Maternal and perinatal outcomes in twin pregnancies following assisted reproduction: a systematic review and meta-analysis involving 802 462 pregnancies

BACKGROUND

ART is associated with higher rates of twin pregnancies than singleton pregnancies. Whether twin pregnancies conceived following ART have additional maternal and neonatal complications compared with non-ART twin pregnancies is not known.

OBJECTIVE AND RATIONALE

The objective was to quantify the risk of adverse maternal and perinatal outcomes among twin pregnancies conceived following ART compared with non-ART and natural conception. Existing reviews vary in the reported outcomes, with many studies including triplet pregnancies in the study population. Therefore, we aimed to perform an up-to-date review with an in-depth analysis of maternal and perinatal outcomes limited to twin pregnancies.

SEARCH METHODS

We searched electronic databases MEDLINE and EMBASE from January 1990 to May 2023 without language restrictions. All cohort studies reporting maternal and perinatal outcomes following ART compared with non-ART twin pregnancies and natural conception were included. Case-control studies, case reports, case series, animal studies, and in vitro studies were excluded. The Newcastle-Ottawa Scale was used to assess the methodological quality of the studies. Using random-effects meta-analysis, the estimates were pooled and the findings were reported as odds ratios (OR) with 95% CI.

OUTCOMES

We included 111 studies (802 462 pregnancies). Twin pregnancies conceived following ART were at higher risk of preterm birth at <34 weeks (OR 1.33, 95% CI 1.14-1.56, 29 studies, I2 = 73%), <37 weeks (OR 1.26, 95% CI 1.19-1.33, 70 studies, I2 = 76%), hypertensive disorders in pregnancy (OR 1.29, 95% CI 1.14-1.46, 59 studies, I2 = 87%), gestational diabetes mellitus (OR 1.61, 95% CI 1.48-1.75, 51 studies, I2 = 65%), and caesarean delivery (OR 1.80, 95% CI 1.65-1.97, 70 studies, I2 = 89%) compared with non-ART twins. The risks for the above maternal outcomes were also increased in the ART group compared with natural conception. Of the perinatal outcomes, ART twins were at significantly increased risk of congenital malformations (OR 1.17, 95% CI 1.05-1.30, 39 studies, I2 = 59%), birthweight discordance (>25% (OR 1.31, 95% CI 1.05-1.63, 7 studies, I2 = 0%)), respiratory distress syndrome (OR 1.32, 95% CI 1.09-1.60, 16 studies, I2 = 61%), and neonatal intensive care unit admission (OR 1.24, 95% CI 1.14-1.35, 32 studies, I2 = 87%) compared with non-ART twins. When comparing ART with natural conception, the risk of respiratory distress syndrome, intensive care admissions, and birthweight discordance >25% was higher among the ART group. Perinatal complications, such as stillbirth (OR 0.83, 95% CI 0.70-0.99, 33 studies, I2 = 49%), small for gestational age <10th centile (OR 0.90, 95% CI 0.85-0.95, 26 studies, I2 = 36%), and twin-twin transfusion syndrome (OR 0.45, 95% CI 0.25-0.82, 9 studies, I2 = 25%), were reduced in twin pregnancies conceived with ART versus those without ART. The above perinatal complications were also fewer amongst the ART group than natural conception.

WIDER IMPLICATIONS

ART twin pregnancies are associated with higher maternal complications than non-ART pregnancies and natural conception, with varied perinatal outcomes. Women seeking ART should be counselled about the increased risks of ART twin pregnancies and should be closely monitored in pregnancy for complications. We recommend exercising caution when interpreting the study findings owing to the study's limitations.

Neonatal outcomes in infants conceived using assisted reproductive technologies: A single medical center cohort study

BACKGROUND

A significant rise in the use of assisted reproductive technology (ART) has been observed, but concerns about its impact on neonatal outcomes have been considered. The aim of this retrospective cohort study is to determine the association between ART and the risk of neonatal complications and congenital anomalies within a recent time period.

METHODS

This retrospective study enrolled infants born after 20 weeks of gestation at a tertiary hospital in Taiwan between January 2019 and December 2021. The study population was divided into two groups: (1) ART pregnancy group and (2) natural pregnancy group. Maternal and neonatal characteristics, pregnancy complications, and neonatal outcomes were compared between the two groups. Multivariate logistic regression was used to adjust for maternal characteristics, preexisting maternal conditions, pregnancy complications, delivery methods, and infant characteristics.

RESULTS

This study enrolled 1770 infants comprising 289 in the ART pregnancy group and 1481 in the natural pregnancy group. The ART pregnancy group showed higher rates of multiple births, preterm births, low birth weights, and longer hospitalization periods. In the stratified analyses that were conducted on singleton births, no significant difference was observed. In the case of multiple births, lower rates of preterm birth, low birth weight, and respiratory support were observed in the ART pregnancy group. After adjusting for maternal and infant characteristics, ART was not considered a significant risk factor for adverse neonatal outcomes, including mortality, complications, and congenital anomalies.

CONCLUSION

Although ART pregnancies were more likely to result in multiple births and furthermore adverse outcomes, ART itself was not associated with an increased risk of poor neonatal outcomes. By implementing measures to control the number of implanted embryos, ensuring appropriate prenatal screening, and providing comprehensive postnatal care, the risks associated with increased multiple pregnancies caused by ART may be reduced.

Change of HeART: Cardiovascular Implications of Assisted Reproductive Technology

Cardiovascular (CV) disease is the leading cause of death in women, and it may manifest differently than in men, in part related to sex-specific CV risk factors. In females, assisted reproductive technologies (ARTs) are commonly used to treat infertility, and they utilize controlled ovarian stimulation involving the administration of exogenous sex hormones. ARTs, and especially controlled ovarian stimulation, have been associated with an increased pregnancy and short-term CV risk, although the long-term CV implications of these treatments in individuals treated with ARTs and their offspring remain unclear. This review endeavors to provide a comprehensive examination of what is known about the relationship between ART and CV outcomes for females treated with ARTs, as well as their offspring, and recommendations for future research. Novel insights into female-specific CV risk factors are critical to reduce the disproportionate burden of CV disease in Canadian women. ART has revolutionized reproductive medicine, offering hope to millions of individuals with infertility worldwide, and a further understanding of the CV implications of this important sex-specific CV risk factor is warranted urgently.

Association between cesarean section rate and maternal age in twin pregnancies

OBJECTIVES

To evaluate the effect of maternal age to the cesarean section rate of twin pregnancies in late preterm and term gestation.

METHODS

A retrospective study was performed on twin pregnancies delivered at Seoul National University Bundang Hospital from June 2003 to December 2020. Preterm births before 34 weeks of gestation were excluded, and only live births were analyzed. The patients were classified into four groups according to maternal age (<30, 30-34, 35-39, and ≥40 years). The primary outcome was the rate of cesarean section.

RESULTS

The median value of maternal body mass index, the rate of assisted reproductive technology, dichorionic twin pregnancy, preeclampsia, and gestational diabetes increased significantly according to the maternal age group (all p<0.05). Among a total of 2,075 twin pregnancies, the rates of cesarean section were 65, 74, 80, and 95% for groups with maternal age under 30, 30-34, 35-39, and ≥40 years, respectively (p<0.001). The cesarean section rates after a trial of labor were 22, 22, 28, and 63%, respectively (p=0.032). Maternal old age was an independent risk factor for cesarean section after a trial of labor in both nulliparous and multiparous women after adjusting for confounding factors.

CONCLUSIONS

The rate of cesarean section in twin pregnancies significantly increased as maternal age increased, even in multiparous women.

Obstetric Outcomes and Successful Reduction of Twin Pregnancies Achieved by In Vitro Fertilization

The use of in vitro fertilization methods around the world is constantly increasing. In some developed countries, up to 5% of newborns are as a result of pregnancies after IVF procedures. In vitro fertilization as one of the main and widespread methods for treatment of infertility is the main reason for the high frequency of multiple pregnancies, which, in many countries, is still too high. Most of the multiple pregnancies are in fact twin pregnancies. Twin pregnancies, regardless of how they are achieved, are associated with large number of complications compared with singleton ones. More often these pregnancies can lead to maternal complications and adverse pregnancy outcomes. Maternal complications include development of preeclampsia, gestational diabetes, placenta previa, placental abruption, premature rupture of membranes, antepartum and postpartum hemorrhage, and delivery by cesarean sections. Adverse pregnancy outcomes mostly include preterm birth (PTB), low birth weight (LBW), small for gestational age newborn (SGA), intrauterine growth restriction (IUGR), neonatal respiratory distress syndrome (RDS), and admission to neonatal intensive care unit (NICU). A number of studies have found differences in the course of twin pregnancies according to their mode of occurrence – spontaneous or after IVF. Some of them have found that twin pregnancies after IVF are associated with poorer obstetric and perinatal outcomes, others do not find such a difference, and there are even studies that find a better outcome in IVF twin pregnancies. Twin pregnancy is a common occurrence after IVF procedure, because multiple-embryo transfer is commonly regarded as an effective strategy to improve the likelihood of a successful pregnancy. Understanding the risks of these pregnancies should be a strong motive for the transfer of fewer embryos during IVF procedures. The most effective way to do this is to transfer a single-embryo into the uterus in cases, where this is justified and the chances of getting pregnant are high. An important element in achieving this goal is the use of methods for vitrification of embryos, which leads to a sufficiently high rate of clinical pregnancies after freezing of embryos obtained by IVF and their subsequent transfer after thawing in case of failure of fresh ET.

Assisted Reproductive Technology Surveillance - United States, 2018

Problem/Condition

Since the first U.S. infant conceived with assisted reproductive technology (ART) was born in 1981, both the use of ART and the number of fertility clinics providing ART services have increased steadily in the United States. ART includes fertility treatments in which eggs or embryos are handled in the laboratory (i.e., in vitro fertilization [IVF] and related procedures). Although the majority of infants conceived through ART are singletons, women who undergo ART procedures are more likely than women who conceive naturally to have multiple births because multiple embryos might be transferred. Multiple births can pose substantial risks for both mothers and infants, including obstetric complications, preterm birth (<37 weeks), and low birthweight (<2,500 g). This report provides state-specific information for the United States (including the District of Columbia and Puerto Rico) on ART procedures performed in 2018 and compares birth outcomes that occurred in 2018 (resulting from ART procedures performed in 2017 and 2018) with outcomes for all infants born in the United States in 2018.

Period Covered

2018.

Description of System

In 1995, CDC began collecting data on ART procedures performed in fertility clinics in the United States as mandated by the Fertility Clinic Success Rate and Certification Act of 1992 (Public Law 102–493 [October 24, 1992]). Data are collected through the National ART Surveillance System (NASS), a web-based data collection system developed by CDC. This report includes data from the 50 U.S. states, the District of Columbia, and Puerto Rico.

Results

In 2018, a total of 203,119 ART procedures (range: 196 in Alaska to 26,028 in California) were performed in 456 U.S. fertility clinics and reported to CDC. These procedures resulted in 73,831 live-birth deliveries (range: 76 in Puerto Rico and Wyoming to 9,666 in California) and 81,478 infants born (range: 84 in Wyoming to 10,620 in California). Nationally, among women aged 15–44 years, the rate of ART procedures performed was 3,135 per 1 million women. ART use exceeded 1.5 times the national rate in seven states (Connecticut, Illinois, Maryland, Massachusetts, New Jersey, New York, and Rhode Island) and the District of Columbia. ART use rates exceeded the national rate in an additional seven states (California, Delaware, Hawaii, New Hampshire, Utah, Vermont, and Virginia).

Nationally, among all ART transfer procedures, the average number of embryos transferred was similar across age groups (1.3 among women aged <35 years, 1.3 among women aged 35–37 years, and 1.4 among women aged >37 years). The national single-embryo transfer (SET) rate among all embryo-transfer procedures was 74.1% among women aged <35 years (range: 28.2% in Puerto Rico to 89.5% in Delaware), 72.8% among women aged 35–37 years (range: 30.6% in Puerto Rico to 93.7% in Delaware), and 66.4% among women aged >37 years (range: 27.1% in Puerto Rico to 85.3% in Delaware).

In 2018, ART contributed to 2.0% of all infants born in the United States (range: 0.4% in Puerto Rico to 5.1% in Massachusetts) from procedures performed in 2017 and 2018. Approximately 78.6% of ART-conceived infants were singleton infants. Overall, ART contributed to 12.5% of all multiple births, including 12.5% of all twin births and 13.3% of all triplets and higher-order births. ART-conceived twins accounted for approximately 97.1% (15,532 of 16,001) of all ART-conceived multiple births. The percentage of multiple births was higher among infants conceived with ART (21.4%) than among all infants born in the total birth population (3.3%). Approximately 20.7% (15,532 of 74,926) of ART-conceived infants were twins, and 0.6% (469 of 74,926) were triplets and higher-order multiples.

Nationally, infants conceived with ART contributed to 4.2% of all low birthweight (<2,500 g) infants. Among ART-conceived infants, 18.3% were low birthweight compared with 8.3% among all infants. ART-conceived infants contributed to 5.1% of all preterm (gestational age <37 weeks) infants. The percentage of preterm births was higher among infants conceived with ART (26.1%) than among all infants born in the total birth population (10.0%).

The percentage of low birthweight among singletons was 8.3% among ART-conceived infants and 6.6% among all infants born. The percentage of preterm births among ART-conceived singleton infants was 14.9% compared with 8.3% among all singleton infants. The percentages of small for gestational age infants was 7.3% among ART-conceived infants compared with 9.4% among all infants.

Interpretation

Although singleton infants accounted for the majority of ART-conceived infants, multiple births from ART varied substantially among states and nationally, contributing to >12% of all twins, triplets, and higher-order multiple infants born in the United States. Because multiple births are associated with higher rates of prematurity than singleton births, the contribution of ART to poor birth outcomes continues to be noteworthy. Although SET rates increased among all age groups, variations in SET rates among states and territories remained, which might reflect variations in embryo-transfer practices among fertility clinics and might in part account for variations in multiple birth rates among states and territories.

Public Health Action

Reducing the number of embryos transferred and increasing use of SET, when clinically appropriate, can help reduce multiple births and related adverse health consequences for both mothers and infants. Whereas risks to mothers from multiple-birth pregnancy include higher rates of caesarean delivery, gestational hypertension, and gestational diabetes, infants from multiple births are at increased risk for numerous adverse sequelae such as preterm birth, birth defects, and developmental disabilities. Long-term follow-up of ART infants through integration of existing maternal and infant health surveillance systems and registries with data available from NASS might be useful for monitoring adverse outcomes on a population basis.

Association Between Ambient Air Pollutants Exposure and Preterm Birth in Women Who Underwent in vitro Fertilization: A Retrospective Cohort Study From Hangzhou, China

Objectives: Exposure to air pollutants has been linked to preterm birth (PTB) after natural conception. However, few studies have explored the effects of air pollution on PTB in patients who underwent in vitro fertilization (IVF). We aimed to investigate the association between ambient air pollutants exposure and PTB risk in IVF patients.

Methods: This retrospective cohort study included 2,195 infertile women who underwent IVF treatment from January 2017 and September 2020 in Hangzhou Women's Hospital. Totally 1,005 subjects who underwent a first fresh embryo(s) transfer cycle were analyzed in this study. Residential exposure to ambient six air pollutants (PM_2.5, PM₁₀, SO₂, NO₂, CO, O₃) during various periods of the IVF timeline were estimated by satellite remote-sensing and ground measurement. Cox proportional hazards models for discrete time were used to explore the association between pollutants exposure and incident PTB, with adjustment for confounders. Stratified analyses were employed to explore the effect modifiers.

Results: The clinical pregnancy and PTB rates were 61.2 and 9.3%, respectively. We found that PM_2.5 exposure was significantly associated with an increased risk of PTB during 85 days before oocyte retrieval [period A, adjusted hazard ratio, HR=1.09, 95%CI: 1.02–1.21], gonadotropin start to oocyte retrieval [period B, 1.07 (1.01–1.19)], first trimester of pregnancy [period F, 1.06 (1.01–1.14)], and the entire IVF pregnancy [period I, 1.07 (1.01–1.14)], respectively. An interquartile range increment in PM₁₀ during periods A and B was significantly associated with PTB at 1.15 (1.04–1.36), 1.12 (1.03–1.28), and 1.14 (1.01–1.32) for NO₂ during period A. The stratified analysis showed that the associations were stronger for women aged <35 years and those who underwent two embryos transferred.

Conclusions: Our study suggests ambient PM_2.5, PM₁₀, and NO₂ exposure were significantly associated with elevated PTB risk in IVF patients, especially at early stages of IVF cycle and during pregnancy.

Maternal and perinatal outcomes of dichorionic diamniotic twins in women after spontaneous and assisted conception

OBJECTIVE

Twin pregnancies have been shown to be associated with numerous maternal and perinatal complications. Published data shows conflicting reports on whether assisted conception influences these risks. The purpose of this study was to assess the impact of mode of conception on maternal and perinatal outcomes of dichorionic diamniotic twin pregnancies.

STUDY DESIGN

This was a large retrospective study of 497 women with dichorionic diamniotic twins that were conceived spontaneously or with assisted conception in a single centre over a 10-year period.

RESULTS

This study showed no significant difference in mode of delivery (OR 1.40 95% CI 0.88 - 2.24), need for admission to neonatal unit (OR 1.56 95% CI 0.88-2.77), or preterm births between dichorionic twin pregnancies conceived following assisted conception when compared to spontaneously conceived dichorionic twin pregnancies. Women who conceived twins by assisted conception that did not have an elective caesarean section were more likely to go into spontaneous labour than have an induction of labour (OR 0.54 95% CI 0.3 - 0.99). They also had a higher chance of having an estimated blood loss of more than 1L than women who conceived naturally (OR 1.70 95% CI 1.06 - 2.73).

CONCLUSIONS

In the case of dichorionic twins, this study showed that assisted conception does not seem to be associated with adverse obstetric and perinatal outcomes when compared with spontaneous conception. These results should be considered reassuring to women undergoing assisted conception, and may assist clinicians when counselling patients for assisted conception treatment. Further research is needed to assess the impact of assisted conception on postpartum blood loss.

Trends of infant mortality and its determinants in Ethiopia: mixed-effect binary logistic regression and multivariate decomposition analysis

BACKGROUND

Infant mortality remains a serious global public health problem. The global infant mortality rate has decreased significantly over time, but the rate of decline in most African countries, including Ethiopia, is far below the rate expected to meet the SDG targets. Therefore, this study aimed to investigate the trends of infant mortality and its determinants in Ethiopia based on the four consecutive Ethiopian Demographic and Health Surveys (EDHSs).

METHODS

This analysis was based on the data from four EDHSs (EDHS 2000, 2005, 2011, and 2016). A total weighted sample of 46,317 live births was included for the final analysis. The logit-based multivariate decomposition analysis was used to identify significantly contributing factors for the decrease in infant mortality in Ethiopia over the last 16 years. To identify determinants, a mixed-effect logistic regression model was fitted. The Intra-class Correlation Coefficient (ICC) and Likelihood Ratio (LR) test were used to assess the presence of a significant clustering effect. Deviance, Akaike Information Criteria (AIC), and Bayesian Information Criteria (BIC) were used for model comparison. Variables with a p-value of less than 0.2 in the bi-variable analysis were considered for the multivariable analysis. In the multivariable analysis, the Adjusted Odds Ratio (AOR) with 95% Confidence Interval (CI) were reported to identify the statistically significant determinants of infant mortality.

RESULTS

Infant mortality rate has decreased from 96.9 per 1000 births in 2000 to 48 per 1000 births in 2016, with an annual rate of reduction of 4.2%. According to the logit based multivariate decomposition analysis, about 18.1% of the overall decrease in infant mortality was due to the difference in composition of the respondents with respect to residence, maternal age, type of birth, and parity across the surveys, while the remaining 81.9% was due to the difference in the effect of residence, parity, type of birth and parity across the surveys. In the mixed-effect binary logistic regression analysis; preceding interval <  24 months (AOR = 1.79, 95% CI; 1.46, 2.19), small size at birth (AOR = 1.55, 95% CI; 1.25, 1.92), large size at birth (AOR = 1.26, 95% CI; 1.01, 1.57), BMI <  18.5 kg/m² (AOR = 1.22, 95% CI; 1.05, 1.50), and twins (AOR = 4.25, 95% CI; 3.01, 6.01), parity> 6 (1.51, 95% CI; 1.01, 2.26), maternal age and male sex (AOR = 1.50, 95% CI: 1.25, 1.79) were significantly associated with increased odds of infant mortality.

CONCLUSION

This study found that the infant mortality rate has declined over time in Ethiopia since 2000. Preceding birth interval, child-size at birth, BMI, type of birth, parity, maternal age, and sex of child were significant predictors of infant mortality. Public health programs aimed at rural communities, and multiparous mothers through enhancing health facility delivery would help maintain Ethiopia's declining infant mortality rate. Furthermore, improving the use of ANC services and maternal nutrition is crucial to reducing infant mortality and achieving the SDG targets in Ethiopia.

Hypertensive disorders of pregnancy by oocyte donation pregnancy in Japanese women aged 40 years or older: a single-center retrospective cohort study

This study aimed to examine the incidence of hypertensive disorders of pregnancy (HDP) among Japanese women with oocyte donation pregnancy (ODP) aged 40 years or older and estimate whether the women with ODP were more likely to develop HDP than those with autologous oocyte pregnancy (AOP) and spontaneous pregnancy (SP). In our study (N = 1361), the proportions of women who developed HDP were 20.5%, 12.8%, and 7.6% for ODP, AOP, and SP, respectively. After adjustment of covariables, the women with ODP were more likely to develop HDP than those with AOP or SP.

Association between IVF/ICSI treatment and preterm birth and major perinatal outcomes among dichorionic-diamnionic twin pregnancies: A seven-year retrospective cohort study

INTRODUCTION

This study aimed to evaluate the preterm birth and additional perinatal outcomes between spontaneous and in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) dichorionic-diamnionic (DCDA) twin pregnancies.

MATERIAL AND METHODS

This retrospective cohort study was conducted in a tertiary university-affiliated medical center. All women with DCDA twin pregnancies were considered for inclusion. The primary outcome of interest was preterm birth <37 weeks of gestation and secondary outcomes included spontaneous preterm birth, iatrogenic (induced) preterm birth, gestational diabetes mellitus, pregnancy-induced hypertensive disorder, preeclampsia, preterm premature rupture of membranes (PPROM), intrahepatic cholestasis of pregnancy, placenta previa, neonatal intensive care unit (NICU) admission, birthweight discordance, small for gestational age, neonatal respiratory distress syndrome, ventilator support, and perinatal death and/or severe morbidity. These outcomes were compared between IVF/ICSI and spontaneous twin pregnancies. Multivariable logistic regressions were used to adjust for confounders. General estimated equation models were used to address intertwin correlation.

RESULTS

A total of 1297 twin pregnancies, including 213 spontaneous and 1084 IVF/ICSI DCDA pregnancies, met the inclusion criteria. Women with IVF/ICSI pregnancies were older and had higher body mass index, adherence with prenatal care and proportion of nulliparity. After adjustment for confounders, IVF/ICSI pregnancies were associated with a slight increase in preterm birth <37 weeks of gestation (adjusted odds ratio [aOR] 1.72; 95% CI 1.24-2.39), iatrogenic preterm birth <37 weeks of gestation (aOR 1.41; 95% CI 1.00-1.97) as well as NICU admission (aOR 1.34; 95% CI 1.00-1.80). IVF/ICSI pregnancies were associated with a decrease in PPROM (aOR 0.64; 95% CI 0.42-0.99). There were no differences between IVF/ICSI and spontaneous DCDA pregnancies in terms of spontaneous preterm birth, gestational diabetes mellitus, pregnancy-induced hypertensive disorder, preeclampsia, intrahepatic cholestasis of pregnancy, placenta previa, birthweight discordance, small for gestational age, neonatal respiratory distress syndrome, ventilator support, and perinatal death and/or severe morbidity.

CONCLUSIONS

IVF/ICSI DCDA twin pregnancies were associated with a slight increase in preterm birth <37 weeks of gestation, iatrogenic preterm birth <37 weeks of gestation, and NICU admission but with a decrease in PPROM. Other outcomes were comparable between IVF/ICSI and spontaneous DCDA twin pregnancies. Multicenter studies with adequate power remain warranted.

[Influence of twin pregnancy by assisted reproductive technology on neonatal outcomes]

OBJECTIVE

To study the influence of twin pregnancy by assisted reproductive technology (ART) versus twin pregnancy by spontaneous conception (SC) on neonatal outcomes.

METHODS

A retrospective analysis was performed for the clinical data of 3 356 live twins with a gestational age of ≥24 weeks who were born in Nanjing Maternal and Child Health Hospital from 2017 to 2019, with 2 006 twins (1 003 pairs) in the ART group and 1 350 (675 pairs) in the SC group. The two groups were compared in terms of the mother's general information and pregnancy comorbidities and the general information, diseases, and outcomes of neonates.

RESULTS

Compared with the SC group, the ART group had a significantly higher maternal age (P < 0.05) and significantly higher rates of primiparity, cesarean section, and cervical cerclage (P < 0.05). Compared with the SC group, the ART group had significantly higher incidence rates of maternal pregnancy comorbidities including hypertension, gestational diabetes, and postpartum hemorrhage (P < 0.05). Compared with the SC group, the ART group had a significantly lower mean gestational age of neonates (P < 0.05) and a significantly higher proportion of very-low-birth-weight infants (6.8% vs 5.8%, P < 0.05), while ART did not increase the risks of preterm birth and low Apgar score. There were no significant differences between the two groups in the mortality rate of neonates and the incidence rates of neonatal diseases including respiratory distress syndrome, stage II/III necrotizing enterocolitis, bronchopulmonary dysplasia, and grade III-IV intracranial hemorrhage (P > 0.05).

CONCLUSIONS

Compared with twin pregnancy by SC, twin pregnancy by ART does not increase the neonatal mortality rate and risk of adverse outcomes.

Neonatal outcomes of extremely preterm twins by sex pairing: an international cohort study

OBJECTIVE

Infant boys have worse outcomes than girls. In twins, the 'male disadvantage' has been reported to extend to female co-twins via a 'masculinising' effect. We studied the association between sex pairing and neonatal outcomes in extremely preterm twins.

DESIGN

Retrospective cohort study SETTING: Eleven countries participating in the International Network for Evaluating Outcomes of Neonates.

PATIENTS

Liveborn twins admitted at 23-29 weeks' gestation in 2007-2015.

MAIN OUTCOME MEASURES

We examined in-hospital mortality, grades 3/4 intraventricular haemorrhage or cystic periventricular leukomalacia (IVH/PVL), bronchopulmonary dysplasia (BPD), retinopathy of prematurity requiring treatment and a composite outcome (mortality or any of the outcomes above).

RESULTS

Among 20 924 twins, 38% were from male-male pairs, 32% were from female-female pairs and 30% were sex discordant. We had no information on chorionicity. Girls with a male co-twin had lower odds of mortality, IVH/PVL and the composite outcome than girl-girl pairs (reference group): adjusted OR (aOR) (95% CI) 0.79 (0.68 to 0.92), 0.83 (0.72 to 0.96) and 0.88 (0.79 to 0.98), respectively. Boys with a female co-twin also had lower odds of mortality: aOR 0.86 (0.74 to 0.99). Boys from male-male pairs had highest odds of BPD and composite outcome: aOR 1.38 (1.24 to 1.52) and 1.27 (1.16 to 1.39), respectively.

CONCLUSIONS

Sex-related disparities in outcomes exist in extremely preterm twins, with girls having lower risks than boys and opposite-sex pairs having lower risks than same-sex pairs. Our results may help clinicians in assessing risk in this large segment of extremely preterm infants.

Assisted Reproductive Technology Surveillance - United States, 2017

PROBLEM/CONDITION

Since the first U.S. infant conceived with assisted reproductive technology (ART) was born in 1981, both the use of ART and the number of fertility clinics providing ART services have increased steadily in the United States. ART includes fertility treatments in which eggs or embryos are handled in the laboratory (i.e., in vitro fertilization [IVF] and related procedures). Although the majority of infants conceived through ART are singletons, women who undergo ART procedures are more likely than women who conceive naturally to have multiple-birth infants because multiple embryos may be transferred. Multiple births can pose substantial risks for both mothers and infants, including obstetric complications, preterm birth (<37 weeks), and low birthweight (<2,500 g). This report provides state-specific information for the United States (including the District of Columbia and Puerto Rico) on ART procedures performed in 2017 and compares birth outcomes that occurred in 2017 (resulting from ART procedures performed in 2016 and 2017) with outcomes for all infants born in the United States in 2017.

PERIOD COVERED

2017.

DESCRIPTION OF SYSTEM

In 1995, CDC began collecting data on ART procedures performed in fertility clinics in the United States as mandated by the Fertility Clinic Success Rate and Certification Act of 1992 (Public Law 102-493 [October 24, 1992]). Data are collected through the National ART Surveillance System (NASS), a web-based data collection system developed by CDC. This report includes data from the 50 states, the District of Columbia, and Puerto Rico.

RESULTS

In 2017, a total of 196,454 ART procedures (range: 162 in Alaska to 24,179 in California) with at least one embryo transferred were performed in 448 U.S. fertility clinics and reported to CDC. These procedures resulted in 68,908 live-birth deliveries (range: 67 in Puerto Rico to 8,852 in California) and 78,052 infants born (range: 85 in Puerto Rico to 9,926 in California). Nationally, the number of ART procedures performed per 1 million women of reproductive age (15-44 years) was 3,040. ART use rates exceeded the national rate in 14 states (Connecticut, Delaware, District of Columbia, Hawaii, Illinois, Maryland, Massachusetts, New Hampshire, New Jersey, New York, Rhode Island, Utah, Vermont, and Virginia). ART use exceeded 1.5 times the national rate in seven states (Connecticut, the District of Columbia, Illinois, Maryland, Massachusetts, New Jersey, and New York). Nationally, among all ART transfer procedures, the average number of embryos transferred increased slightly with increasing age (1.3 among women aged <35 years, 1.4 among women aged 35-37 years, and 1.5 among women aged >37 years). This year, single-embryo transfer (SET) rates among all embryo-transfer procedures are presented instead of elective single-embryo transfer procedures previously reported. Nationally, SET rates were 67.3% (range: 38.9% in South Dakota to 90.4% in Delaware), 65.0% (range: 23.6% in Puerto Rico to 89.4% in Delaware), and 60.0% (range: 28.6% in Puerto Rico to 83.1% in Delaware) among women aged <35 years, aged 35-37 years, and aged >37 years, respectively. In 2017, ART contributed to 1.9% of all infants born in the United States (range: 0.4% in Puerto Rico to 5.0% in Massachusetts). Approximately 73.6% of ART-conceived infants were singleton infants. Overall, ART contributed to 14.7% of all multiple births, including 14.7% of all twin infants and 17.3% of all triplets and higher-order infants. ART-conceived twins accounted for approximately 96.5% (18,890 of 19,570) of all ART-conceived infants born in multiple deliveries. The percentage of multiple births was higher among infants conceived with ART (26.4%) than among all infants born in the total birth population (3.4%). Approximately 25.5% of ART-conceived infants were twins, and 0.9% were triplets and higher-order infants. Nationally, infants conceived with ART contributed to 4.5% of all low birthweight (<2,500 g) infants. Among ART-conceived infants, 20.2% had low birthweight, compared with 8.3% among all infants. ART-conceived infants contributed to 5.3% of all preterm (gestational age <37 weeks) infants. The percentage of preterm births was higher among infants conceived with ART (27.8%) than among all infants born in the total birth population (9.9%). The percentage of low birthweight among singletons was 8.1% among ART-conceived infants and 6.6% among all infants born. The percentage of preterm births among ART-conceived singleton infants was 14.0%, compared with 8.1% among all singleton infants. The percentages of small for gestational age infants was 7.6% among ART-conceived infants, compared with 9.9% among all infants.

INTERPRETATION

Although singleton infants accounted for the majority of ART-conceived infants, multiple births from ART still contributed to a substantial proportion of all twins, triplets, and higher-order infants born in the United States. Variations in SET rates among states and territories were noted, reflecting variations in embryo-transfer practices among fertility clinics, which might in part account for higher multiple birth from ART observed in some states and territories.

PUBLIC HEALTH ACTION

Reducing the number of embryos transferred and increasing use of SET, when clinically appropriate, can help reduce multiple births and related adverse health consequences for both mothers and infants. Because infants from multiple births are at increased risk for numerous adverse sequelae that cannot be ascertained from the data collected through NASS alone, long-term follow-up for ART infants through integration of existing maternal and infant health surveillance systems and registries with data available from NASS might be useful for monitoring adverse outcomes on a population basis.

Birthweight is an independent predictor of birth asphyxia in twins: A retrospective cross-sectional cohort study of 5337 Chinese twins

OBJECTIVE

Few studies are available on birth asphyxia risks in twin neonates. This retrospective multi-center cross-sectional study determined the birthweight percentiles of 5337twins and birth asphyxia incidence of the twin population.

METHODS

We retrieved sociodemographic and obstetric data from the electronic records systems of participating centers. Neonate birthweight was measured within 24 h of birth. Perinatal asphyxia was diagnosed if 5-minute Apgar score was ≤5, or resuscitation was required 10 min after birth. The primary outcome was the incidence of birth asphyxia.

RESULTS

Totally 5337 neonates were eligible. The mean neonatal birthweight was 2227.1 ± 608.99 g and the 5th, 50th, and 95th percentiles of birthweight were 970, 2400, and 3080 g, respectively. The mean Apgar score was 9.06 ± 1.73 at 1 min and 8.99 ± 1.74 at 5 min. Totally 13.5 % (705/5222) twins had asphyxia and 9.35 % and 4.16 % twins had moderate and severe asphyxia, respectively. Twins with a birthweight< 1500 g had the highest asphyxia rate (64.8 %) and twins with a birthweight between 2500 and 3000 g had the lowest asphyxia rate (3.6 %). Stepwise logistic regression analysis revealed that higher birthweight was associated with a significantly reduced risk of asphyxia [OR 0.772 (95 %CI 0.755, 0.789), P < 0.001]. The AUROC for mean twin birthweight was 0.86±0.01 (95 %CI 0.84, 0.88) using a cutoff of 1950 g, with a sensitivity of 0.84 and a specificity of 0.78.

CONCLUSION

Twins have lower birthweight versus singletons and a significant proportion of twins, especially twins with lower birthweight, are at risk of birth asphyxia. Birthweight is an independent predictor of asphyxia and should be further explored as a predictive marker for stratifying asphyxia risks in twin neonates.

Maternal and Neonatal Complications in Twin Deliveries as Compared to Singleton Deliveries following In vitro Fertilization

Background

Twin pregnancy is an iatrogenic complication following in vitro fertilization (IVF) that can be decreased using elective single-embryo transfer. However, the risks associated with twin pregnancy following IVF as compared to singleton IVF pregnancy need to be further evaluated.

Aim

This study aims to compare the maternal, perinatal, and neonatal complications in singleton and twin pregnancies following IVF-intracytoplasmic sperm injection (ICSI). Settings and Design: Retrospective observational cohort study using previously collected routine patient data.

Materials and Methods

Singleton and twin deliveries following IVF/ICSI from January 2014 to August 2015 were included. Data were collected from patient records and the obstetricians of the patients.

Statistical Analysis Used

SPSS was used for analysis. Student's t-test and Fisher's exact test were used for continuous and categorical data, respectively. Significance was kept at 0.05.

Results

There were 897 singleton and 382 twin deliveries (total of 1661 babies). The mean gestational age at delivery was lower in twin deliveries (34.9 ± 3.1 weeks) as compared to singleton deliveries (36.8 ± 3.2 weeks, P < 0.001). The overall incidence of maternal complications was higher in twin pregnancies (29.3% vs. 21.3%, odds ratio = 1.53, 95% confidence interval = 1.17-2.01; P = 0.003). The mean birth weight of babies was significantly lower (2.02 ± 0.58 kg vs. 2.71 ± 0.68 kg; P < 0.001) and the incidence of stillbirth plus neonatal death was higher (7.5% vs. 4.6%, P = 0.01) in the twin group as compared to the singleton group.

Conclusion

Twin deliveries, following IVF/ICSI deliver at lower gestational age, have lower birth weight and have higher odds of stillbirth plus neonatal death as compared to singleton deliveries following IVF/ICSI.

Maternal and Fetal Risk Associated With Assisted Reproductive Technology

Infertility is a disease that affects up to 15.5% of reproductive-aged couples. Until the birth of the first neonate born from in vitro fertilization (IVF) in 1978, many infertile couples did not have an opportunity to conceive a biological child. Over the past 40 years, access to and effectiveness of IVF have increased; currently 1.7% of births in the United States result from IVF. As with any medical intervention, potential risk exists. In the case of IVF, both maternal risks (ovarian stimulation, oocyte retrieval, and subsequent pregnancy) and fetal risks that vary based on maternal age and fetal number must be considered. Importantly, risk quantification varies by comparison group, which is typically either spontaneous conception in a fertile couple or assisted non-IVF conception in an infertile couple. It must also be considered compared with the alternative of not undergoing IVF, which may mean not having a biological child. Although increased compared with spontaneous conception, absolute maternal-fetal-assisted reproductive technology risks are low and can be minimized by optimizing ovarian stimulation and transferring a single embryo. In this article, we aim to summarize maternal and fetal risk associated with use of assisted reproductive technology. The review focuses on ovarian stimulation and procedural risks as well as adverse perinatal outcomes among resultant singleton and twin pregnancies in young women and women of advanced maternal age.

Impact of the recommendation for embryo transfer limitation on multiple pregnancy: A population-based study in Japan

OBJECTIVE

Limitations on the number of embryos transferred have been recommended worldwide to reduce the number of medically assisted multiple births. Our aim was to evaluate the impact of this recommendation for embryo transfer limitation on perinatal outcomes of multiple births.

STUDY DESIGN

A retrospective and population-based study compared all multiple births in Shiga prefecture of Japan in 2014-2015 (2015 group) with those in 2007-2008 (2008 group). The perinatal background and neonatal outcomes of multiple births were compared.

RESULTS

The number of multiple pregnancies in the 2015 group (n = 251) was almost the same as in the 2008 group (n = 245). The proportion of multiple pregnancies conceived through assisted reproductive technology significantly decreased to 23% in the 2015 group compared to 31% in the 2008 group. In contrast, the rate of ovulation induction significantly increased to 24% in the 2015 group from 15% in the 2008 group. There was no significant difference in the outcome of multiple-birth infants between the two groups.

CONCLUSION

The method of conception in multiple pregnancies markedly shifted from in vitro fertilization to non-in vitro fertilization after the issuance of a recommendation for limits on embryo transfer. It should be necessary for the assessment of the impact of this recommendation to monitor closely multiple pregnancies via non-in vitro fertilization as well as via in vitro fertilization.

Assisted Reproductive Technology Surveillance - United States, 2016

PROBLEM/CONDITION

Since the first U.S. infant conceived with assisted reproductive technology (ART) was born in 1981, both the use of ART and the number of fertility clinics providing ART services have increased steadily in the United States. ART includes fertility treatments in which eggs or embryos are handled in the laboratory (i.e., in vitro fertilization [IVF] and related procedures). Although the majority of infants conceived through ART are singletons, women who undergo ART procedures are more likely than women who conceive naturally to deliver multiple-birth infants. Multiple births pose substantial risks for both mothers and infants, including obstetric complications, preterm delivery (<37 weeks), and low birthweight (<2,500 g). This report provides state-specific information for the United States (including the District of Columbia and Puerto Rico) on ART procedures performed in 2016 and compares birth outcomes that occurred in 2016 (resulting from ART procedures performed in 2015 and 2016) with outcomes for all infants born in the United States in 2016.

PERIOD COVERED

2016.

DESCRIPTION OF SYSTEM

In 1995, CDC began collecting data on ART procedures performed in fertility clinics in the United States as mandated by the Fertility Clinic Success Rate and Certification Act of 1992 (FCSRCA) (Public Law 102-493 [October 24, 1992]). Data are collected through the National ART Surveillance System (NASS), a web-based data collection system developed by CDC. This report includes data from 52 reporting areas (the 50 states, the District of Columbia, and Puerto Rico).

RESULTS

In 2016, a total of 197,706 ART procedures (range: 162 in Wyoming to 24,030 in California) with the intent to transfer at least one embryo were performed in 463 U.S. fertility clinics and reported to CDC. These procedures resulted in 65,964 live-birth deliveries (range: 57 in Puerto Rico to 8,638 in California) and 76,892 infants born (range: 74 in Alaska to 9,885 in California). Nationally, the number of ART procedures performed per 1 million women of reproductive age (15-44 years), a proxy measure of the ART use rate, was 3,075. ART use rates exceeded the national rate in 14 reporting areas (Connecticut, Delaware, the District of Columbia, Hawaii, Illinois, Maryland, Massachusetts, New Hampshire, New Jersey, New York, Pennsylvania, Rhode Island, Utah, and Virginia). ART use exceeded 1.5 times the national rate in nine states, including three (Illinois, Massachusetts, and New Jersey) that also had comprehensive mandated health insurance coverage for ART procedures (i.e., coverage for at least four oocyte retrievals). Nationally, among ART transfer procedures for patients using fresh embryos from their own eggs, the average number of embryos transferred increased with increasing age (1.5 among women aged <35 years, 1.7 among women aged 35-37 years, and 2.2 among women aged >37 years). Among women aged <35 years, the national elective single-embryo transfer (eSET) rate was 42.7% (range: 8.3% in North Dakota to 83.9% in Delaware). In 2016, ART contributed to 1.8% of all infants born in the United States (range: 0.3% in Puerto Rico to 4.7% in Massachusetts). ART also contributed to 16.4% of all multiple-birth infants, including 16.2% of all twin infants and 19.4% of all triplets and higher-order infants. ART-conceived twins accounted for approximately 96.5% (21,455 of 22,233) of all ART-conceived infants born in multiple deliveries. The percentage of multiple-birth infants was higher among infants conceived with ART (31.5%) than among all infants born in the total birth population (3.4%). Approximately 30.4% of ART-conceived infants were twins and 1.1% were triplets and higher-order infants. Nationally, infants conceived with ART contributed to 5.0% of all low birthweight (<2,500 g) infants. Among ART-conceived infants, 23.6% had low birthweight compared with 8.2% among all infants. ART-conceived infants contributed to 5.3% of all preterm (gestational age <37 weeks) infants. The percentage of preterm births was higher among infants conceived with ART (29.9%) than among all infants born in the total birth population (9.9%). The percentage of ART-conceived infants who had low birthweight was 8.7% among singletons, 54.9% among twins, and 94.9% among triplets and higher-order multiples; the corresponding percentages among all infants born were 6.2% among singletons, 55.4% among twins, and 94.6% among triplets and higher-order multiples. The percentage of ART-conceived infants who were born preterm was 13.7% among singletons, 64.2% among twins, and 97.0% among triplets and higher-order infants; the corresponding percentages among all infants were 7.8% for singletons, 59.9% for twins, and 97.7% for triplets and higher-order infants.

INTERPRETATION

Multiple births from ART contributed to a substantial proportion of all twins, triplets, and higher-order infants born in the United States. For women aged <35 years, who typically are considered good candidates for eSET, on average, 1.5 embryos were transferred per ART procedure, resulting in higher multiple birth rates than could be achieved with single-embryo transfers. Of the four states (Illinois, Massachusetts, New Jersey, and Rhode Island) with comprehensive mandated health insurance coverage, three (Illinois, Massachusetts, and New Jersey) had rates of ART use >1.5 times the national average. Although other factors might influence ART use, insurance coverage for infertility treatments accounts for some of the difference in per capita ART use observed among states because most states do not mandate any coverage for ART treatment.

PUBLIC HEALTH ACTION

Twins account for almost all of ART-conceived multiple births born in multiple deliveries. Reducing the number of embryos transferred and increasing use of eSET, when clinically appropriate, could help reduce multiple births and related adverse health consequences for both mothers and infants. Because multiple-birth infants are at increased risk for numerous adverse sequelae that cannot be ascertained from the data collected through NASS alone, long-term follow-up of ART infants through integration of existing maternal and infant health surveillance systems and registries with data available from NASS might be useful for monitoring adverse outcomes.

Neonatal outcomes among twins stratified by method of conception: secondary analysis of maternal fetal medicine (MFMU) network database

PURPOSE

To investigate whether twin pregnancies conceived by different forms of fertility treatments are associated with adverse neonatal outcomes and to examine the difference in maternal and obstetrical characteristics between patients.

METHODS

Our study was a retrospective analysis of twin pregnancies conceived by fertility treatments from a prospectively collected database. Treatments were stratified into two groups: group 1 (ART) consisted of in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI), and group 2 (non-ART) included intrauterine insemination (IUI) and ovulation induction (OI). Composite neonatal morbidity included respiratory distress syndrome, intraventricular hemorrhage, leukomalacia, chronic lung disease, and death prior to discharge.

RESULTS

There were 460 neonates in our study; among them, 67% (n = 310) were in group 1, and 33% (n = 150) in group 2. Group 1 patients were more likely to be older (p = 0.004), nulliparous (p = 0.01), delivered twins with lower birth weights (2278 g ± 605 vs. 2427 ± 519, p = 0.009), and had more deliveries < 32 weeks gestation (p = 0.001). In multivariable Poisson regression model, only neonatal intensive care unit admission rate was increased for group 1 twins (aRR = 1.27, 95% CI 1.003-1.60).

CONCLUSIONS

After adjusting for confounders, twins conceived via ART compared to non-ART had similar neonatal outcomes. These data can help when counseling this patient population and assist in planning larger prospective cohorts.

Assisted Reproductive Technology Surveillance - United States, 2015

PROBLEM/CONDITION

Since the first U.S. infant conceived with assisted reproductive technology (ART) was born in 1981, both the use of ART and the number of fertility clinics providing ART services have increased steadily in the United States. ART includes fertility treatments in which eggs or embryos are handled in the laboratory (i.e., in vitro fertilization [IVF] and related procedures). Although the majority of infants conceived through ART are singletons, women who undergo ART procedures are more likely than women who conceive naturally to deliver multiple-birth infants. Multiple births pose substantial risks for both mothers and infants, including obstetric complications, preterm delivery (<37 weeks), and low birthweight (<2,500 g) infants. This report provides state-specific information for the United States (including the District of Columbia and Puerto Rico) on ART procedures performed in 2015 and compares birth outcomes that occurred in 2015 (resulting from ART procedures performed in 2014 and 2015) with outcomes for all infants born in the United States in 2015.

PERIOD COVERED

2015.

DESCRIPTION OF SYSTEM

In 1995, CDC began collecting data on ART procedures performed in fertility clinics in the United States as mandated by the Fertility Clinic Success Rate and Certification Act of 1992 (FCSRCA) (Public Law 102-493 [October 24, 1992]). Data are collected through the National ART Surveillance System, a web-based data collection system developed by CDC. This report includes data from 52 reporting areas (the 50 states, the District of Columbia, and Puerto Rico).

RESULTS

In 2015, a total of 182,111 ART procedures (range: 135 in Alaska to 23,198 in California) with the intent to transfer at least one embryo were performed in 464 U.S. fertility clinics and reported to CDC. These procedures resulted in 59,334 live-birth deliveries (range: 55 in Wyoming to 7,802 in California) and 71,152 infants born (range: 68 in Wyoming to 9,176 in California). Nationally, the number of ART procedures performed per 1 million women of reproductive age (15-44 years), a proxy measure of the ART utilization rate, was 2,832. ART use exceeded the national rate in 13 reporting areas (California, Connecticut, Delaware, the District of Columbia, Hawaii, Illinois, Maryland, Massachusetts, New Hampshire, New Jersey, New York, Rhode Island, and Virginia). Nationally, among ART transfer procedures in patients using fresh embryos from their own eggs, the average number of embryos transferred increased with increasing age of the woman (1.6 among women aged <35 years, 1.8 among women aged 35-37 years, and 2.3 among women aged >37 years). Among women aged <35 years, the national elective single-embryo transfer (eSET) rate was 34.7% (range: 11.3% in Puerto Rico to 88.1% in Delaware). In 2015, ART contributed to 1.7% of all infants born in the United States (range: 0.3% in Puerto Rico to 4.5% in Massachusetts). ART also contributed to 17.0% of all multiple-birth infants, 16.8% of all twin infants, and 22.2% of all triplets and higher-order infants. The percentage of multiple-birth infants was higher among infants conceived with ART (35.3%) than among all infants born in the total birth population (3.4%). Approximately 34.0% of ART-conceived infants were twins and 1.0% were triplets and higher-order infants. Nationally, infants conceived with ART contributed to 5.1% of all low birthweight infants. Among ART-conceived infants, 25.5% had low birthweight, compared with 8.1% among all infants. ART-conceived infants contributed to 5.3% of all preterm (gestational age <37 weeks) infants. The percentage of preterm births was higher among infants conceived with ART (31.2%) than among all infants born in the total birth population (9.7%). Among singletons, the percentage of ART-conceived infants who had low birthweight was 8.7% compared with 6.4% among all infants born. The percentage of ART-conceived infants who were born preterm was 13.4% among singletons compared with 7.9% among all infants.

INTERPRETATION

Multiple births from ART contributed to a substantial proportion of all twins, triplets, and higher-order infants born in the United States. For women aged <35 years, who are typically considered good candidates for eSET, the national average of 1.6 embryos was transferred per ART procedure. Of the four states (Illinois, Massachusetts, New Jersey, and Rhode Island) with comprehensive mandated health insurance coverage for ART procedures (i.e., coverage for at least four cycles of IVF), three (Illinois, Massachusetts, and New Jersey) had rates of ART use exceeding 1.5 times the national rate. This type of mandated insurance coverage has been associated with greater use of ART and likely accounts for some of the difference in per capita ART use observed among states.

PUBLIC HEALTH ACTION

Twins account for the majority of ART-conceived multiple births. Reducing the number of embryos transferred and increasing use of eSET when clinically appropriate could help reduce multiple births and related adverse health consequences for both mothers and infants. State-based surveillance of ART might be useful for monitoring and evaluating maternal and infant health outcomes of ART in states with high ART use.

Adverse pregnancy, birth, and infant outcomes in twins: effects of maternal fertility status and infant gender combinations; the Massachusetts Outcomes Study of Assisted Reproductive Technology

BACKGROUND

It is unknown whether the risk of adverse outcomes in twin pregnancies among subfertile women, conceived with and without in vitro fertilization, differs from those conceived spontaneously.

OBJECTIVE

We sought to evaluate the effects of fertility status on adverse perinatal outcomes in twin pregnancies on a population basis.

STUDY DESIGN

All twin live births of ≥22 weeks' gestation and ≥350 g birthweight to Massachusetts resident women in 2004 through 2010 were linked to hospital discharge records, vital records, and in vitro fertilization cycles. Women were categorized by their fertility status as in vitro fertilization, subfertile, or fertile, and by twin pair genders (all, like, unlike). Women whose births linked to in vitro fertilization cycles were classified as in vitro fertilization; those with indicators of subfertility but without in vitro fertilization treatment were classified as subfertile; all others were classified as fertile. Risks of 6 adverse pregnancy outcomes (gestational diabetes, pregnancy hypertension, uterine bleeding, placental complications [placenta abruptio, placenta previa, and vasa previa], prenatal hospitalizations, and primary cesarean) and 9 adverse infant outcomes (very low birthweight, low birthweight, small-for-gestation birthweight, large-for-gestation birthweight, very preterm [<32 weeks], preterm, birth defects, neonatal death, and infant death) were modeled by fertility status with the fertile group as reference, using multivariate log binomial regression and reported as adjusted relative risk ratios and 95% confidence intervals.

RESULTS

The study population included 10,352 women with twin pregnancies (6090 fertile, 724 subfertile, and 3538 in vitro fertilization). Among all twins, the risks for all 6 adverse pregnancy outcomes were significantly increased for the subfertile and in vitro fertilization groups, with highest risks for uterine bleeding (adjusted relative risk ratios, 1.92 and 2.58, respectively) and placental complications (adjusted relative risk ratios, 2.07 and 1.83, respectively). Among all twins, the risks for those born to subfertile women were significantly increased for very preterm birth and neonatal and infant death (adjusted relative risk ratios, 1.36, 1.89, and 1.87, respectively). Risks were significantly increased among in vitro fertilization twins for very preterm birth, preterm birth, and birth defects (adjusted relative risk ratios, 1.28, 1.07, and 1.26, respectively).

CONCLUSION

Risks of all maternal and most infant adverse outcomes were increased for subfertile and in vitro fertilization twins. Among all twins, the highest risks were for uterine bleeding and placental complications for the subfertile and in vitro fertilization groups, and neonatal and infant death in the subfertile group. These findings provide further evidence supporting single embryo transfer and more cautious use of ovulation induction.

Pregnancy, birth, and infant outcomes by maternal fertility status: the Massachusetts Outcomes Study of Assisted Reproductive Technology

BACKGROUND

Births to subfertile women, with and without infertility treatment, have been reported to have lower birthweights and shorter gestations, even when limited to singletons. It is unknown whether these decrements are due to parental characteristics or aspects of infertility treatment.

OBJECTIVE

The objective of the study was to evaluate the effect of maternal fertility status on the risk of pregnancy, birth, and infant complications.

STUDY DESIGN

All singleton live births of ≥22 weeks' gestation and ≥350 g birthweight to Massachusetts resident women in 2004-2010 were linked to hospital discharge and vital records. Women were categorized by their fertility status as in vitro fertilization, subfertile, or fertile. Women whose births linked to in vitro fertilization cycles from the Society for Assisted Reproductive Technology Clinic Outcomes Reporting System were classified as in vitro fertilization. Women with indicators of subfertility but not treated with in vitro fertilization were classified as subfertile. Women without indicators of subfertility or in vitro fertilization treatment were classified as fertile. Risks of 15 adverse outcomes (gestational diabetes, pregnancy hypertension, antenatal bleeding, placental complications [placenta abruptio and placenta previa], prenatal hospitalizations, primary cesarean delivery, very low birthweight [<1500 g], low birthweight [<2500 g], small-for-gestation birthweight [z-score ≤-1.28], large-for-gestation birthweight [z-score ≥1.28], very preterm [<32 weeks], preterm [<37 weeks], birth defects, neonatal death [0-27 days], and infant death [0-364 days of life]) were modeled by fertility status with the fertile group as reference and the subfertile group as reference, using multivariate log binomial regression and reported as adjusted risk ratios and 95% confidence intervals.

RESULTS

The study population included 459,623 women (441,420 fertile, 8054 subfertile, and 10,149 in vitro fertilization). Women in the subfertile and in vitro fertilization groups were older than their fertile counterparts. Risks for 6 of 6 pregnancy outcomes and 6 of 9 infant outcomes were increased for the subfertile group, and 5 of 6 pregnancy outcomes and 7 of 9 infant outcomes were increased for the in vitro fertilization group. For 4 of the 6 pregnancy outcomes (uterine bleeding, placental complications, prenatal hospitalizations, and primary cesarean) and 2 of the infant outcomes (low birthweight and preterm) the risk was greater in the in vitro fertilization group, with nonoverlapping confidence intervals to the subfertile group, indicating a substantially higher risk among in vitro fertilization-treated women. The highest risks for the in vitro fertilization women were uterine bleeding (adjusted risk ratio, 3.80; 95% confidence interval, 3.31-4.36) and placental complications (adjusted risk ratio, 2.81; 95% confidence interval, 2.57-3.08), and for in vitro fertilization infants, very preterm birth (adjusted risk ratio, 2.13; 95% confidence interval, 1.80-2.52), and very low birthweight (adjusted risk ratio, 2.15; 95% confidence interval, 1.80-2.56). With subfertile women as reference, risks for the in vitro fertilization group were significantly increased for uterine bleeding, placental complications, prenatal hospitalizations, primary cesarean delivery, low and very low birthweight, and preterm and very preterm birth.

CONCLUSION

These analyses indicate that, compared with fertile women, subfertile and in vitro fertilization-treated women tend to be older, have more preexisting chronic conditions, and are at higher risk for adverse pregnancy outcomes, particularly uterine bleeding and placental complications. The greater risk in in vitro fertilization-treated women may reflect more severe infertility, more extensive underlying pathology, or other unfavorable factors not measured in this study.

Assisted Reproductive Technology Surveillance - United States, 2014

PROBLEM/CONDITION

Since the first U.S. infant conceived with assisted reproductive technology (ART) was born in 1981, both the use of ART and the number of fertility clinics providing ART services have increased steadily in the United States. ART includes fertility treatments in which eggs or embryos are handled in the laboratory (i.e., in vitro fertilization [IVF] and related procedures). Women who undergo ART procedures are more likely than women who conceive naturally to deliver multiple-birth infants. Multiple births pose substantial risks to both mothers and infants, including obstetric complications, preterm delivery, and low birthweight infants. This report provides state-specific information for the United States (including the District of Columbia and Puerto Rico) on ART procedures performed in 2014 and compares birth outcomes that occurred in 2014 (resulting from ART procedures performed in 2013 and 2014) with outcomes for all infants born in the United States in 2014.

PERIOD COVERED

2014.

DESCRIPTION OF SYSTEM

In 1996, CDC began collecting data on ART procedures performed in fertility clinics in the United States as mandated by the Fertility Clinic Success Rate and Certification Act of 1992 (FCSRCA) (Public Law 102-493). Data are collected through the National ART Surveillance System (NASS), a web-based data collection system developed by CDC. This report includes data from 52 reporting areas (the 50 states, the District of Columbia, and Puerto Rico).

RESULTS

In 2014, a total of 169,568 ART procedures (range: 124 in Wyoming to 21,018 in California) with the intent to transfer at least one embryo were performed in 458 U.S. fertility clinics and reported to CDC. These procedures resulted in 56,028 live-birth deliveries (range: 52 in Wyoming to 7,230 in California) and 68,782 infants born (range: 64 in Wyoming to 8,793 in California). Nationally, the total number of ART procedures performed per million women of reproductive age (15-44 years), a proxy measure of the ART usage rate, was 2,647 (range: 364 in Puerto Rico to 6,726 in Massachusetts). ART use exceeded the national average in 13 reporting areas (Connecticut, Delaware, the District of Columbia, Hawaii, Illinois, Maryland, Massachusetts, New Hampshire, New Jersey, New York, Pennsylvania, Rhode Island, and Virginia). Eight reporting areas (Connecticut, the District of Columbia, Hawaii, Illinois, Maryland, Massachusetts, New Jersey, and New York) had rates of ART use exceeding 1.5 times the national average. Nationally, among ART transfer procedures in patients using fresh embryos from their own eggs, the average number of embryos transferred increased with increasing age of the woman (1.7 among women aged <35 years, 1.9 among women aged 35-37 years, and 2.3 among women aged >37 years). Among women aged <35 years, who typically are considered to be good candidates for elective single embryo transfer (eSET) procedures, the national eSET rate was 28.5% (range: 4.3% in Puerto Rico to 67.9% in Delaware). In 2014, ART contributed to 1.6% of all infants born in the United States (range: 0.4% in Puerto Rico to 4.7% in Massachusetts) and 18.3% of all multiple-birth infants (range: 5.5% in Alaska and West Virginia to 37.3% in Hawaii), including 18.0% of all twin infants (range: 5.2% in some states to 36.2% in Hawaii) and 26.4% of all triplets and higher-order infants (range: 0% in some states to 65.2% in Hawaii). Percentages of live births that were multiple-birth deliveries were higher among infants conceived with ART (39.4%; range: 11.5% in Delaware to 55.6% in Puerto Rico) than among all infants born in the total birth population (3.5%; range: 2.2% in Puerto Rico to 4.4% in New Jersey). Approximately 38.0% of ART-conceived infants were twin infants, and 2.0% were triplets and higher-order infants. ART-conceived twins accounted for approximately 95.3% of all ART-conceived infants born in multiple deliveries. Nationally, infants conceived with ART contributed to 5.5% of all low birthweight (<2,500 g) infants (range: 1.2% in West Virginia to 14.2% in Massachusetts). Among ART-conceived infants, 27.8% were low birthweight (range: 10.6% in Delaware to 44.4% in Puerto Rico), compared with 8.0% among all infants (range: 5.9% in Alaska to 11.3% in Mississippi). ART-conceived infants contributed to 4.7% of all preterm (<37 weeks) infants (range: 1.2% in Puerto Rico to 13.4% in Massachusetts). Percentages of preterm births were higher among infants conceived with ART (33.2%; range: 18.9% in the District of Columbia to 45.9% in Puerto Rico) than among all infants born in the total birth population (11.3%; range: 8.5% in California to 16.0% in Mississippi). The percentage of ART-conceived infants who were low birthweight was 8.9% (range: 3.2% in some states to 16.1% in Vermont) among singletons and 55.2% (range: 38.5% in Delaware to 77.8% in Alaska) among twins; the corresponding percentages of low birthweight infants among all infants born were 6.3% for singletons (range: 4.6% in Alaska, North Dakota, and Oregon to 9.5% in Puerto Rico) and 55.2% for twins (range: 46.1% in Alaska to 65.6% in Mississippi). The percentage of ART-conceived infants who were preterm was 13.2% (range: 7.5% in Rhode Island to 23.4% in West Virginia) among singletons and 62.2% (range: 33.3% in some states to 81.4% in Mississippi) among twins; the corresponding percentages of preterm infants among all infants were 9.7% for singletons (range: 1.7% in the District of Columbia to 14.2% in Mississippi) and 56.6% for twins (range: 47.2% in Vermont to 66.9% in Wyoming).

INTERPRETATION

The percentage of infants conceived with ART varied considerably by reporting area. Multiple births from ART contributed to a substantial proportion of all twins, triplets, and higher-order infants born. Low birthweight and preterm infant birth rates were disproportionately higher among ART-conceived infants than among the overall birth population. Although women aged <35 years are typically considered good candidates for eSET, on average two embryos were transferred per ART procedure with women in this group. Compared with ART-conceived singletons, ART-conceived twins were approximately five times more likely to be born preterm and approximately six times more likely to be born with low birthweight. Singleton infants conceived with ART had higher percentages of preterm birth and low birthweight than all singleton infants born in the United States. ART use per population unit was geographically variable, with 13 reporting areas showing ART use higher than the national rate. Of the four states (Illinois, Massachusetts, New Jersey, and Rhode Island) with comprehensive statewide-mandated health insurance coverage for ART procedures (i.e., coverage for at least four cycles of IVF), three (Illinois, Massachusetts, and New Jersey) had rates of ART use exceeding 1.5 times the national rate. This type of mandated insurance has been associated with greater use of ART and likely accounts for some of the difference in per capita ART use observed among states.

PUBLIC HEALTH ACTION

Reducing the number of embryos transferred and increasing use of eSET when clinically appropriate could help reduce multiple births and related adverse health consequences. Because twins account for the majority of ART-conceived multiple births, improved provider practices and patient education and counseling on the maternal and infant health risks of having twins are needed. Although ART contributes to high percentages of multiple births, other factors not investigated in this report (e.g., delayed childbearing and use of non-ART fertility treatments) also contribute to multiple births and warrant further study.

Perinatal outcomes of singleton siblings: the effects of changing maternal fertility status

PURPOSE

The objective of this study was to evaluate the effect of changing fertility status on perinatal outcomes of singleton siblings, conceived with and without assisted reproductive technology (ART).

METHOD

A longitudinal cohort study of Massachusetts resident women having two consecutive singleton births during 2004-2010 was performed. Women were classified as ART (A), subfertile (S), or fertile (F) and categorized by their fertility status in each birth as A-A, A-S, S-A, S-S, F-A, F-S, and F-F. Within categories, adjusted mean birthweights, gestations, and birthweight Z scores were estimated with linear generalized estimating equations. Risks of low birthweight (LBW, <2500 g), preterm birth (PTB, <37 weeks), and placental complications were modeled using logistic regression by fertility status as adjusted odds ratios (AORs) and 95 % confidence intervals (CIs).

RESULTS

Birthweights in second pregnancies averaged 74-155 g higher, except for births to F-A women, who averaged -16 g lower. Most women had a reduction in length of gestation in their second pregnancies, with F-A women having the largest decline (-0.5 weeks). In first birth models, the risks for LBW and placental complications were increased for subfertile (AOR 1.39 [1.07-1.81] and 1.97 [1.33-2.93], respectively) and ART women (AOR 1.58 [1.29-1.93] and 3.40 [2.64-4.37], respectively). Second birth models showed increased risks for ART births of LBW (AOR 3.13 [2.19-4.48]) and placental complications (AOR 2.45 [1.56-3.86]) and greater risks of PTB for both ART (AOR 2.37 [1.74-3.23]) and subfertile women (AOR 1.47 [1.02-2.13]).

CONCLUSIONS

Declining fertility status, with and without assisted reproductive technology treatment, is associated with increasing risks for adverse outcomes, greatest for women whose fertility status declined the most.

Is artificial reproductive technology a risk factor for retinopathy of prematurity independent of the generation of multiple births?

PURPOSE

There is some debate regarding whether artificial reproductive technology (ART) constitutes an independent risk factor for retinopathy of prematurity (ROP). We wanted to assess the prevalence of ART in multiple birth infants seen for ROP screening and whether or not ROP was identified or treated, in order to evaluate whether ART contributes a risk factor for ROP independent of the generation of multiple births.

METHODS

A retrospective audit was performed of all multiple birth babies admitted to a tertiary neonatal unit who met the UK ROP screening criteria (<32 weeks gestational age [GA] and/or <1,501 g birthweight [BW]).

RESULTS

A total of 205 babies met our criteria, of whom 87.3% were twins. A total of 39.5% were born following ART. A total of 30.5% of the non-ART group developed ROP vs 34% of the ART group (p = 0.837). Stage 3 ROP developed in 5.1% of non-ART babies and 6% of ART babies. A total of 8.5% of non-ART babies and 10% of ART babies required treatment for ROP. Logistic regression demonstrated that ART was not independently associated with development of ROP.

CONCLUSIONS

Artificial reproductive technology multiple birth babies make up a considerable proportion of the ROP screening burden and their number is likely to increase as ART is increasingly available and utilized. We found no significant difference between the numbers of babies developing ROP in the ART vs non-ART groups, but the numbers are small. The estimated odds of developing ROP are slightly higher in the ART babies, so our data do not rule out a possible association.

Clinical outcomes after assisted reproductive technology in twin pregnancies: chorionicity-based comparison

The chorionicity–based evaluation of the perinatal risk in twin pregnancies after assisted reproductive technology (ART) is lacking. A retrospective review was performed of all twin pregnancies monitored prenatally and delivered at our hospital between 2010 and 2014. Chorionicity was diagnosed by ultrasound examination at first trimester and confirmed by postnatal pathology. Pregnancy and perinatal outcomes were prospectively recorded. Adjusted odds ratios (aOR) with 95% confidence intervals (CI) were calculated in a logistic regression model. A total of 1153 twin pregnancies were analyzed. The occurrence of preterm premature rupture of membranes (PPROM) was 3 times as frequent in monochorionic diamniotic (MCDA) twin pregnancies after ART as in those spontaneous counterparts (aOR 3.0; 95%CI 1.1–3.2). The prevalence of intrahepatic cholestasis of pregnancies (ICP) was significantly higher in dichorionic diamniotic (DCDA) twin pregnancies following ART compared to spontaneous DCDA pregnancies (aOR 3.3; 95%CI 1.3–5.6). Perinatal outcomes did not differ between two conception methods, either in MCDA or DCDA twin pregnancies. Based on differentiation of chorionicity, ART is associated with the increased risk of PPROM in MCDA twin pregnancies and with a higher rate of ICP in DCDA twin gestations. ART does not increase adversity of perinatal outcomes in twin pregnancies.

Validation of birth outcomes from the Society for Assisted Reproductive Technology Clinic Outcome Reporting System (SART CORS): population-based analysis from the Massachusetts Outcome Study of Assisted Reproductive Technology (MOSART)

OBJECTIVE

To assess the validity of outcome data reported to the Society for Assisted Reproductive Technology Clinic Outcome Reporting System (SART CORS) compared with data from vital records and the birth defects registry in Massachusetts.

DESIGN

Longitudinal cohort.

SETTING

Not applicable.

PARTICIPANT(S)

A total of 342,035 live births and fetal deaths from Massachusetts mothers giving birth in the state from July 1, 2004, to December 31, 2008; 9,092 births and fetal deaths were from mothers who had conceived with the use of assisted reproductive technology (ART) and whose cycle data had been reported to the SART CORS.

INTERVENTION(S)

Not applicable.

MAIN OUTCOME MEASURE(S)

Percentage agreement between maternal race and ethnicity, delivery outcome (live birth or fetal death), plurality (singleton, twin, or triplet+), delivery date, and singleton birth weight reported in the SART CORS versus vital records; sensitivity and specificity for birth defects among singletons as reported in the SART CORS versus the Massachusetts Birth Defects Monitoring Program (BDMP).

RESULT(S)

There was >95% agreement between the SART CORS and vital records for fields of maternal race/ethnicity, live birth/fetal death, and plurality; birth outcome date was within 1 day with 94.9% agreement and birth weight was within 100 g with 89.6% agreement. In contrast, sensitivity for report of any birth defect was 38.6%, with a range of 18.4%-50.0%, for specific birth defect categories.

CONCLUSION(S)

Although most SART CORS outcome fields are accurately reported, birth defect variables showed poor sensitivity compared with the gold standard data from the BDMP. We suggest that reporting of birth defects be discontinued.

Assisted reproductive technology and perinatal outcomes: conventional versus discordant-sibling design

OBJECTIVE

To compare risks of adverse perinatal outcomes between assisted reproductive technology (ART) and naturally conceived singleton births using a dual design approach.

DESIGN

Discordant-sibling and conventional cross-sectional general population comparison.

SETTING

Not applicable.

PATIENT(S)

All singleton live births, conceived naturally or via ART.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Birth weight, gestational age, low birth weight, preterm delivery, small for gestational age (SGA), low Apgar score.

RESULT(S)

A total of 32,762 (0.8%) of 3,896,242 singleton live births in the three states were conceived via ART. In 6,458 sibling pairs, ART-conceived singletons were 33 g lighter (adjusted β = -33.40, 95% confidence interval [CI], -48.60, -18.21) and born half a day sooner (β = -0.58, 95% CI, -1.02, -0.14) than singletons conceived naturally. The absolute risk of low birth weight and preterm birth was 6.8% and 9.7%, respectively, in the ART group and 4.9% and 7.9%, respectively, in the non-ART group. The odds of low birth weight were 33% higher (adjusted odds ratio [aOR] = 1.33; 95% CI, 1.13, 1.56) and 20% higher for preterm birth (aOR = 1.20; 95% CI, 1.07, 1.34). The odds of SGA and low Apgar score were not significantly different in both groups (aOR = 1.22; 95% CI, 0.88, 1.68; and aOR = 0.75; 95% CI, 0.54, 1.05, respectively). Results of conventional analyses were similar, although the magnitude of risk was higher for preterm birth (aOR, 1.51; 95% CI 1.46, 1.56).

CONCLUSION(S)

Despite some inflated risks in the general population comparison, ART remained associated with an increased likelihood of low birth weight and preterm birth when underlying maternal factors were kept constant using discordant-sibling comparison.

Obstetric outcome and incidence of congenital anomalies in 2351 IVF/ICSI babies

PURPOSE

The aim of this study was to provide a comprehensive follow-up of fetal and perinatal outcome and the incidence of congenital anomalies in babies born after fresh embryo transfers compared to those conceived spontaneously in infertile couples.

METHODS

Retrospective comparative analysis of all clinical pregnancies from fresh cleavage-stage embryo transfer cycles (IVF and ICSI) compared with infertile patients who conceived spontaneously in the same time period (control). Congenital anomalies were classified following the European Surveillance of Congenital Anomalies (EUROCAT) classification.

RESULTS

A total of 2414 assisted reproductive technology (ART) pregnancies were compared to 582 spontaneous conceptions in the control infertile group representing 2306 deliveries. No significant differences were found in pregnancy outcome between the two groups (delivery rate, abortion rate, ectopic pregnancies, medical abortions for fetal anomalies, single and twins mean gestational age, and weight at delivery). A significant difference (p < 0.001) was found in the twin (21.3 vs 2.3 %) and triplet rates (2.3 vs 0 %). A total of 2351 babies were delivered in the ART group and 449 in the control group. A total of 90 babies (3.8 %) were diagnosed with a major congenital anomaly in the ART group and 15 (3.3 %) in the control group (p = ns). The overall rate of major congenital anomalies (105/2800) in ART and spontaneous pregnancies in infertile couples was significantly higher when compared to the EUROCAT 2.0 versus 3.75 % (p = 0.0002).

DISCUSSION

Babies born after ART treatments and from spontaneous conception in infertile couples had rates of congenital anomalies higher than those recorded by the EUROCAT. However, the rates of anomalies were not different within the infertile population whether conceived by ART or spontaneously. These data suggest that the diagnosis of infertility in itself is the common denominator for the increase in the rates of anomalies seen in both ART and spontaneous conceptions.

Dizygotic twin pregnancies after medically assisted reproduction and after natural conception: maternal and perinatal outcomes

OBJECTIVE

To compare maternal and perinatal outcomes in dizygotic twin pregnancies conceived after medically assisted reproduction (MAR) with outcomes after natural conception (NC).

DESIGN

Nationwide registry based study.

SETTING

Academic medical center.

PATIENT(S)

Primiparous women who delivered opposite sex twins between January 2000 and December 2012 in the Netherlands, comprising dizygotic twin pregnancies: 6,694 women, 470 after ovulation induction (OI), 511 after intrauterine insemination with controlled ovarian hyperstimulation (IUI-COH), 2,437 after in vitro fertilization (IVF) with intracytoplasmic sperm injection (ICSI), and 3,276 after NC.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Multivariable logistic regression and generalized linear mixed models to evaluate differences in outcomes: maternal outcomes of hypertension, preeclampsia, preterm delivery, hemorrhage, and delivery mode, perinatal outcomes including small for gestational age (SGA) with birth weight <10th percentile, birth weight <1,500 g, 5-minute Apgar score <7, admission to neonatal intensive care unit, congenital anomalies, and perinatal mortality.

RESULT(S)

We found no statistically significant differences in maternal or perinatal outcomes after OI compared with NC. Women pregnant after IVF-ICSI had a lower risk for hypertension (adjusted odds ratio [aOR] 0.74; 95% confidence interval [CI], 0.66-0.83) compared with women pregnant after NC. After IUI-COH more children had Apgar scores <7 (adjusted odds ratio (aOR) 1.38; 95% confidence interval (CI) 1.05-1.81) and perinatal mortality rates were higher (aOR 1.56; 95% CI, 1.04-2.33) compared with NC. We found no differences in perinatal outcomes after IVF-ICSI compared with NC.

CONCLUSION(S)

Overall, maternal and perinatal risks other than those due to multiplicity are similar for twin pregnancies conceived after MAR and after NC.

Factors associated with the use of elective single-embryo transfer and pregnancy outcomes in the United States, 2004-2012

OBJECTIVE

To evaluate factors associated with elective single-embryo transfer (eSET) utilization and its effect on assisted reproductive technology outcomes in the United States.

DESIGN

Historical cohort.

SETTING

Not applicable.

PATIENT(S)

Fresh IVF cycles of women aged 18-37 years using autologous oocytes with either one (SET) or two (double-embryo transfer [DET]) embryos transferred and reported to the Society for Assisted Reproductive Technology Clinic Outcome Reporting System between 2004 and 2012. Cycles were categorized into four groups with ([+]) or without ([-]) supernumerary embryos cryopreserved. The SET group with embryos cryopreserved was designated as eSET.

INTERVENTION(S)

None.

MAIN OUTCOMES MEASURE(S)

The likelihood of eSET utilization, live birth, and singleton non-low birth weight term live birth, modeled using logistic regression. Presented as adjusted odds ratios (aORs) and 95% confidence intervals (CIs).

RESULT(S)

The study included 263,375 cycles (21,917 SET[-]cryopreservation, 20,996 SET[+]cryopreservation, 103,371 DET[-]cryopreservation, and 117,091 DET[+]cryopreservation). The utilization of eSET (SET[+]cryopreservation) increased from 1.8% in 2004 to 14.9% in 2012 (aOR 7.66, 95% CI 6.87-8.53) and was more likely with assisted reproductive technology insurance coverage (aOR 1.60, 95% CI 1.54-1.66), Asian race (aOR 1.26, 95% CI 1.20-1.33), uterine factor diagnosis (aOR 1.48, 95% CI 1.37-1.59), retrieval of ≥16 oocytes (aOR 2.85, 95% CI 2.55-3.19), and the transfer of day 5-6 embryos (aOR 4.23, 95% CI 4.06-4.40); eSET was less likely in women aged 35-37 years (aOR 0.76, 95% CI 0.73-0.80). Compared with DET cycles, the likelihood of the ideal outcome, term non-low birth weight singleton live birth, was increased 45%-52% with eSET.

CONCLUSION(S)

Expanding insurance coverage for IVF would facilitate the broader use of eSET and may reduce the morbidity and healthcare costs associated with multiple pregnancies.

Assisted Reproductive Technology and Early Intervention Program Enrollment

OBJECTIVES

We examined the prevalence of Early Intervention (EI) enrollment in Massachusetts comparing singleton children conceived via assisted reproductive technology (ART), children born to mothers with indicators of subfertility but no ART (Subfertile), and children born to mothers who had no indicators of subfertility and conceived naturally (Fertile). We assessed the natural direct effect (NDE), the natural indirect effect (NIE) through preterm birth, and the total effect of ART and subfertility on EI enrollment.

METHODS

We examined maternal and infant characteristics among singleton ART (n = 6447), Subfertile (n = 5515), and Fertile (n = 306,343) groups and characteristics associated with EI enrollment includingpreterm birth using χ(2) statistics (α = 0.05). We estimated the NDE and NIE of the ART-EI enrollment relationship by fitting a model for enrollment, conditional on ART, preterm and the ART-preterm delivery interaction, and covariates. Similar analyses were conducted by using Subfertile as the exposure.

RESULTS

The NDE indicated that the odds of EI enrollment were 27% higher among the ART group (odds ratioNDE = 1.27; 95% confidence interval (CI): 1.19 ̶ 1.36) and 20% higher among the Subfertilegroup (odds ratioNDE = 1.20; 95% CI: 1.12 ̶ 1.29) compared with the Fertile group, even if the rate of preterm birth is held constant.

CONCLUSIONS

Singleton children conceived through ART and children of subfertile mothers both have elevated risks of EI enrollment. These findings have implications for clinical providers as they counsel women about child health outcomes associated with ART or subfertility.

Comparative analysis of perinatal outcome of spontaneous pregnancy reduction and multifetal pregnancy reduction in triplet pregnancies conceived after assisted reproductive technique

INTRODUCTION

With the advent of assisted reproductive treatment options, the incidence of multiple pregnancies has increased. Although the need for elective single embryo transfer is emphasized time and again, its uniform applicability in practice is yet a distant goal. In view of the fact that triplet and higher order pregnancies are associated with significant fetomaternal complications, the fetal reduction is a commonly used option in such cases. This retrospective study aims to compare the perinatal outcome in patients with triplet gestation who have undergone spontaneous fetal reduction (SFR) as against those in whom multifetal pregnancy reduction (MFPR) was done.

MATERIALS AND METHODS

In the present study, eighty patients with triplet gestation at 6 weeks were considered. The patients underwent SFR or MFPR at or before 12-13 weeks and were divided into two groups (34 and 46), respectively.

RESULTS

Our study found no statistical difference in perinatal outcome between the SFR and MFPR groups in terms of average gestational age at delivery, abortion rate, preterm delivery rate, and birth weight. The study shows that the risk of aborting all fetuses after SFR is three times (odds ratio [OR] = 3.600, 95% confidence interval [CI] = 0.2794-46.388) that of MFPR in subsequent 2 weeks. There were more chances of loss of extra fetus in SFR (23.5%) group than MFPR group (8.7%) (OR = 3.889, 95% CI = 1.030-14.680). As neither group offers any significant benefit from preterm delivery, multiple pregnancies continue to be responsible for preterm delivery despite fetal reduction.

CONCLUSION

There appears to be some advantages of MFPR in perinatal outcome when compared to SFR, especially if the latter happens at advanced gestation. Therefore, although it is advisable to wait for SFR to occur, in patients with triplet gestation at 11-12 weeks, MFPR is a viable option to be considered.

Is the wrong question being asked in infertility research?

A persistent finding is that assisted reproductive technology (ART) is associated with compromised birth outcomes, including higher risks for prematurity, low birthweight, and congenital malformations, even among singletons. Over the past decade, our research group, the Massachusetts Outcome Study of Assisted Reproductive Technology (MOSART), has evaluated pregnancy and birth outcomes among three groups of women, those women treated with ART, those with indicators of subfertility but without ART treatment, and fertile women. We have also explored the influence of infertility-related diagnoses on outcomes for women and infants. Over the course of our research, we have changed our perspective from an original focus on ART treatment parameters as the primary cause of excess morbidity to one centered instead on the underlying infertility-related diagnoses. This paper summarizes the research findings from our group that support this change in focus for infertility-based research from a primary emphasis on ART treatment to greater attention to the contribution of preexisting pathology underlying the infertility and suggests directions for future analyses.

Assisted Reproductive Technology Surveillance - United States, 2013

PROBLEM/CONDITION

Since the first U.S. infant conceived with assisted reproductive technology (ART) was born in 1981, both the use of ART and the number of fertility clinics providing ART services have increased steadily in the United States. ART includes fertility treatments in which eggs or embryos are handled in the laboratory (i.e., in vitro fertilization [IVF] and related procedures). Women who undergo ART procedures are more likely than women who conceive naturally to deliver multiple-birth infants. Multiple births pose substantial risks to both mothers and infants, including obstetric complications, preterm delivery, and low birthweight infants. This report provides state-specific information for the United States (including Puerto Rico) on ART procedures performed in 2013 and compares infant outcomes that occurred in 2013 (resulting from ART procedures performed in 2012 and 2013) with outcomes for all infants born in the United States in 2013.

REPORTING PERIOD COVERED

2013.

DESCRIPTION OF SYSTEM

In 1996, CDC began collecting data on ART procedures performed in fertility clinics in the United States as mandated by the Fertility Clinic Success Rate and Certification Act of 1992 (FCSRCA) (Public Law 102-493). Data are collected through the National ART Surveillance System (NASS), a web-based data collection system developed by CDC. This report includes data from 52 reporting areas (the 50 states, the District of Columbia [DC], and Puerto Rico).

RESULTS

In 2013, a total of 160,521 ART procedures (range: 109 in Wyoming to 20,299 in California) with the intent to transfer at least one embryo were performed in 467 U.S. fertility clinics and were reported to CDC. These procedures resulted in 53,252 live-birth deliveries (range: 47 in Alaska to 6,979 in California) and 66,691 infants (range: 61 in Alaska to 8,649 in California). Nationally, the total number of ART procedures performed per million women of reproductive age (15-44 years), a proxy measure of the ART usage rate, was 2,521 (range: 352 in Puerto Rico to 7,688 in DC). ART use exceeded the national rate in 13 reporting areas (California, Connecticut, Delaware, Hawaii, Illinois, Maryland, Massachusetts, New Hampshire, New Jersey, New York, Rhode Island, Virginia, and DC). Nationally, among ART transfer procedures in patients using fresh embryos from their own eggs, the average number of embryos transferred increased with increasing age of the woman (1.8 among women aged <35 years, 2.0 among women aged 35-37 years, and 2.5 among women aged >37 years). Among women aged <35 years, who typically are considered to be good candidates for elective single embryo transfer (eSET) procedures, the national eSET rate was 21.4% (range: 4.0% in Idaho to 77.5% in Delaware). In 2013, ART contributed to 1.6% of all infants born in the United States (range: 0.2% in Puerto Rico to 4.8% in Massachusetts) and 18.7% of all multiple-birth infants (range: 4.5% in Puerto Rico to 35.7% in Massachusetts), including 18.5% of all twin infants (range: 4.5% in Mississippi to 35.3% in Massachusetts) and 25.2% of all triplet and higher-order infants (range: 0% in several reporting areas to 51.5% in New Jersey). Multiple-birth deliveries were higher among infants conceived with ART (41.1%; range: 20.4% in Delaware to 61.6% in Wyoming) than among all infants born in the total birth population (only 3.5%; range: 1.8% in Puerto Rico to 4.5% in Massachusetts and New Jersey). Approximately 39% of ART-conceived infants were twin infants, and 2% were triplet and higher-order infants. ART-conceived twins accounted for approximately 95.4% of all ART-conceived infants born in multiple deliveries. Nationally, infants conceived with ART contributed to 5.8% of all low birthweight (<2,500 grams) infants (range: 0.9% in Puerto Rico to 15.1% in Massachusetts). Among ART-conceived infants, 29.1% were low birthweight (range: 18.3% in Delaware to 42.6% in Louisiana), compared with 8.0% among all infants (range: 5.8% in Alaska to 11.5% in Mississippi). ART-conceived infants contributed to 4.6% of all preterm (<37 weeks) infants (range: 0.6% in Puerto Rico to 13.3% in Massachusetts). Preterm birth rates were higher among infants conceived with ART (33.6%; range: 22.3% in DC to 50.7% in Louisiana) than among all infants born in the total birth population (11.4%; range: 8.8% in California to 16.6% in Mississippi). The percentage of ART-conceived infants who were low birthweight was 9.0% (range: 5.1% in Mississippi to 19.7% in Puerto Rico) among singletons and 56.3% (range: 48.3% in Maine to 72.4% in Puerto Rico) among twins; the corresponding percentages among all infants born were 6.3% for singletons (range: 4.6% in Alaska to 9.6% in Mississippi and Puerto Rico) and 55.3% for twins (range: 43.6% in Alaska to 65.6% in Mississippi). The percentage of ART-conceived infants who were preterm varied from 13.3% (range: 8.7% in Rhode Island to 26.9% in West Virginia) among singletons to 61.0% (range: 47.8% in DC to 78.8% in Oklahoma) among twins; the corresponding percentages among all infants were 10.1% for singletons (range: 6.8% in Vermont to 14.8% in Mississippi) and 56.6% for twins (range: 44.7% in New Hampshire to 68.9% in Louisiana).

INTERPRETATION

The percentage of infants conceived with ART varied considerably by reporting area. In most reporting areas, multiple births from ART contributed to a substantial proportion of all twins, triplets, and higher-order infants born, and the low birthweight and preterm infant birth rates were disproportionately higher among ART-conceived infants than among the overall birth population. Although women aged <35 years are typically considered good candidates for eSET, on average two embryos were transferred per ART procedure with women in this group, increasing the overall multiple-birth rates in the United States. Compared with ART-conceived singletons, ART-conceived twins were approximately four-and-a-half times more likely to be born preterm, and approximately six times more likely to be born with low birthweight. Singleton infants conceived with ART had slightly higher rates of preterm delivery and low birthweight than all singleton infants born in the United States. ART use per population unit was geographically variable, with 13 reporting areas showing ART use above the national rate. Of the four states (Illinois, Massachusetts, New Jersey, and Rhode Island) with comprehensive statewide-mandated health insurance coverage for ART procedures (i.e., coverage for at least four cycles of IVF), two states (Massachusetts and New Jersey) had rates of ART use exceeding twice the national level. This type of mandated insurance has been associated with greater use of ART and likely accounts for some of the difference in per capita ART use observed among states.

PUBLIC HEALTH ACTIONS

Reducing the number of embryos transferred per ART procedure and increasing use of eSET, when clinically appropriate (typically for women aged <35 years), could help reduce multiple births, particularly ART-conceived twin infants, and related adverse consequences of ART. Because twins account for the majority of ART-conceived multiple births, improved patient education and counseling on the maternal and infant health risks of having twins is needed. Although ART contributes to high rates of multiple births, other factors not investigated in this report (e.g., delayed childbearing and non-ART fertility treatments) also contribute to multiple births and warrant further study.

Adverse pregnancy outcomes after in vitro fertilization: effect of number of embryos transferred and plurality at conception

OBJECTIVE

To evaluate risks for adverse pregnancy outcomes by number of embryos transferred (ET) and fetal heartbeats (FHB) in assisted reproductive technology-conceived singleton live births.

DESIGN

Longitudinal cohort using cycles reported to the Society for Assisted Reproductive Technology Clinic Outcomes Reporting System between 2004 and 2008 among women who were treated and gave birth in Massachusetts.

SETTING

Not applicable.

PATIENT(S)

Assisted reproductive technology data on 6,073 births between 2004 and 2008 were linked to vital records and hospital data. Likelihood of ET ≥3 vs. 1-2, FHB >1 vs. 1, and risks of preterm birth (PTB, <37 weeks' gestation), low birth weight (LBW, <2,500 g), and small-for-gestational-age birth weight (SGA, <10th percentile) with FHB >1 were modeled with binary logistic regression using a backward-stepping algorithm, and presented as adjusted odds ratios (95% confidence intervals).

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

ET ≥3, FHB >1, PTB, LBW, and SGA.

RESULT(S)

Higher ET was significantly more likely with older maternal age, intracytoplasmic sperm injection, assisted hatching, cleavage-stage embryos, and thawed embryos. The likelihood of FHB >1 with ≥3 ET vs. 1-2 ET was 2.04 (1.68-2.48). Risks of PTB and LBW with FHB >1 were 1.63 (1.27-2.09) and 1.81 (1.36-2.39), respectively; the risk of SGA was not significant. Nulliparity was associated with higher risks of PTB (1.34 [1.12-1.59]), LBW (1.48 [1.20-1.83]), and SGA (2.17 [1.69-2.78]).

CONCLUSION(S)

Number of embryos transferred was strongly associated with FHBs, with twice the risk of FHB >1 with ≥3 ET vs. 1-2 ET. Increasing FHBs were associated with significantly greater risks for PTB and LBW outcomes.

Triplet Pregnancy: Is the Mode of Conception Related to Perinatal Outcomes?

Many triplets are conceived as a consequence of assisted reproductive technology (ART). Concerns have been raised that triplet pregnancies conceived by ART are more complicated than those conceived spontaneously. The purpose of this study was to evaluate all triplet pregnancies managed over a 12-year period to determine if there were any differences in outcome based on the mode of conception. All triplet pregnancies between 1999 and 2011 that reached at least 20 weeks’ gestation and that were managed at the Royal Women's Hospital (RWH), Melbourne, Victoria were identified. Maternal and neonatal outcomes were compared between ART conceived and spontaneously conceived triplets. In the study period, 53 sets of triplets managed in our institution met the eligibility criteria. Twenty-five triplet sets were conceived by ART and 28 were conceived spontaneously. More ART conceptions resulted in trichorionic triamniotic (TCTA) triplets than did spontaneous conceptions (p= .015). There were no differences between ART and spontaneously conceived triplets for any of the maternal or neonatal complications studied. Trichorionic (TC) triplets delivered at a later gestation than other triplets: 32.1 (SD2.9) versus 30.4 (SD3.9) weeks (p= .08). TC triplets were significantly less likely to die than monochorionic (MC) or dichorionic (DC) triplets: 3/93 (3%) versus 13/66 (20%) (p= .025). In conclusion, triplets conceived by ART are more likely to have TCTA placentation and TCTA triplet sets had lower mortality rates than other triplet combinations. Outcomes for triplets conceived by ART were similar to those of triplets conceived spontaneously.

Association between assisted reproductive technology conception and autism in California, 1997-2007

OBJECTIVES

We assessed the association between assisted reproductive technology (ART) and diagnosed autistic disorder in a population-based sample of California births.

METHODS

We performed an observational cohort study using linked records from the California Birth Master Files for 1997 through 2007, the California Department of Developmental Services autism caseload for 1997 through 2011, and the Centers for Disease Control and Prevention's National ART Surveillance System for live births in 1997 through 2007. Participants were all 5 926 251 live births, including 48 865 ART-originated infants and 32 922 cases of autism diagnosed by the Department of Developmental Services. We compared births originated using ART with births originated without ART for incidence of autism.

RESULTS

In the full population, the incidence of diagnosed autism was twice as high for ART as non-ART births. The association was diminished by excluding mothers unlikely to use ART; adjustment for demographic and adverse prenatal and perinatal outcomes reduced the association substantially, although statistical significance persisted for mothers aged 20 to 34 years.

CONCLUSIONS

The association between ART and autism is primarily explained by adverse prenatal and perinatal outcomes and multiple births.

Perinatal outcomes associated with assisted reproductive technology: the Massachusetts Outcomes Study of Assisted Reproductive Technologies (MOSART)

OBJECTIVE

To compare on a population basis the birth outcomes of women treated with assisted reproductive technologies (ART), women with indicators of subfertility but without ART, and fertile women.

DESIGN

Longitudinal cohort study.

SETTING

Not applicable.

PARTICIPANT(S)

A total of 334,628 births and fetal deaths to Massachusetts mothers giving birth in a Massachusetts hospital from July 1, 2004, to December 31, 2008, subdivided into three subgroups for comparison: ART 11,271, subfertile 6,609, and fertile 316,748.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Four outcomes-preterm birth, low birth weight, small for gestational age, and perinatal death-were modeled separately for singletons and twins with the use of logistic regression for the primary comparison between ART births and those to the newly created population-based subgroup of births to women with indicators of subfertility but no ART.

RESULT(S)

For singletons, the risks for both preterm birth and low birth weight were higher for the ART group (adjusted odds ratios [AORs] 1.23 and 1.26, respectively) compared with the subfertile group, and risks in both the ART and the subfertile groups were higher than those among the fertile births group. For twins, the risk of perinatal death was significantly lower among ART births than fertile (AOR 0.55) or subfertile (AOR 0.15) births.

CONCLUSION(S)

The use of a population-based comparison group of subfertile births without ART demonstrated significantly higher rates of preterm birth and low birth weight in ART singleton births, but these differences are smaller than differences between ART and fertile births. Further refinement of the measurement of subfertile births and examination of the independent risks of subfertile births is warranted.

Epidemiology of twinning in the National Birth Defects Prevention Study, 1997 to 2007

BACKGROUND

Our objective was to evaluate associations between twinning and maternal demographic factors and periconceptional exposures among infants with and without orofacial clefts.

METHODS

We used data from the National Birth Defects Prevention Study; 228 twins and 8242 singletons without birth defects (controls), and 117 twins and 2859 singletons with orofacial clefts, born 1997 to 2007, were included in the analyses. Because of the occurrence of twinning due to the use of assisted reproductive technologies, logistic regression models were computed to estimate odds ratios and 95% confidence intervals for each exposure, stratified by fertility treatment use. To evaluate factors by zygosity, we used sex-pairing data and a simulation approach to estimate the zygosity of like-sex twin pairs for unassisted conceptions.

RESULTS

Among control mothers who did not use fertility treatments, predictors of twinning included non-Hispanic black maternal race (adjusted odds ratio, 1.6; 95% confidence interval, 1.0-2.4), and tobacco smoking (adjusted odds ratio, 1.6; 95% confidence interval, 1.1-2.4). Among control mothers who used fertility treatments, older maternal age, higher income, and state of residence were associated with twinning. Associations were generally stronger among mothers of dizygotic (estimated) twins than monozygotic (estimated) twins. Results for mothers of infants with isolated orofacial clefts were similar to those of controls.

CONCLUSION

We observed an increased twinning frequency with increasing maternal age, but factors such as maternal race/ethnicity and socioeconomic status may also contribute. Among women receiving fertility treatments, factors associated with twinning suggested a relation with treatment specifics (e.g., treatment type and number of embryos implanted) and availability of insurance coverage.

Early prediction of spontaneous twin very preterm birth: a population based study 2002-2012

OBJECTIVE

The aim of this study was to establish early pregnancy risk indicators for spontaneous twin very preterm birth.

METHODS

We conducted a retrospective observational population-based study. Twenty-one potential early pregnancy risk factors were analyzed using multivariable logistic regression to determine which of them was independently associated with spontaneous twin very preterm birth.

RESULTS

Of 1815 spontaneous twin births 15.3% (277) occurred before 32 weeks. Previous preterm delivery (aOR 3.73; 95% CI, 2.52-5.52), nulliparity (aOR 2.94; 95% CI, 2.09-4.14), body mass index <18.5 (aOR 1.86; 95% CI, 1.12-3.10), body mass index ≥30 (aOR 1.87; 95% CI, 1.21-2.89), hysteroscopic metroplasty (aOR 1.63; 1.07-2.49), conization (aOR 2.05; 95% CI, 1.07-3.94) and monochorionicity (aOR 1.83; 95% CI, 1.28-2.63) were significantly associated with twin very preterm birth.

CONCLUSIONS

Pending verification in other populations, twin pregnancies at significant risk for spontaneous very preterm birth can be identified in early pregnancy using several risk indicators.

Mortality and major morbidities in very preterm infants born from assisted conception or naturally conceived: results of the area-based ACTION study

BACKGROUND

The use of assisted conception (AC) has been associated with higher risk of adverse perinatal outcome. Few data are available on the outcome of AC-neonates when pregnancy ends before 32 weeks of gestational age.The aim of this study was to compare the short-term outcome of AC- and naturally conceived preterm infants <32 weeks gestation.

METHODS

The area-based cohort study ACTION collected data on births 22-31 weeks gestation occurred in 2003-05 in 6 Italian regions. Infants born to 2529 mothers with known mode of conception were studied. The main outcomes were hospital mortality and survival free from major morbidities (IVH grade 3-4, cPVL, ROP stage ≥3, BPD), and were assessed separately for single and multiple infants. Other outcomes were also investigated. Multivariable logistic analyses were used to adjust for maternal and infants' characteristics. To account for the correlation of observations within intensive care units, robust variance and standard error estimates of regression parameters were computed.

RESULTS

AC was used in 6.4% of mothers. Infants were 2934; 314 (10.7%) were born after AC. Multiples were 86.0% among AC and 21.7% among non-AC babies. In multivariable analysis no statistically significant difference in hospital mortality and survival without major morbidities was found between AC and non-AC infants. The risk of BPD was lower in AC than in non-AC multiples (aOR 0.41, CI 0.20-0.87), and this finding did not change after controlling for mechanical ventilation (aOR 0.42, CI 0.20-0.85) or presence of a patent ductus arteriosus (aOR 0.39, CI 0.18-0.84).

CONCLUSION

When the analysis is restricted to very preterm infants and stratified by multiplicity, no significant associations between AC and increased risk of short-term mortality and survival without major morbidities emerge. This result is consistent with previous studies, and may confirm the hypothesis that the adverse effects of AC are mediated by preterm birth. However, larger appropriately powered studies are needed before definitely excluding the possibility of adverse events linked to AC in infants born before 32 weeks gestation.

Multiple pregnancies following assisted reproductive technologies--a happy consequence or double trouble?

The association between assisted reproduction technologies (ART) and multiple pregnancy is well-established, with a multiple birth rate of 24% in ART pregnancies. Multiple pregnancy is associated with significantly increased maternal and perinatal morbidity and mortality, as well as increased costs to the National Health Service. Evidence relating to the obstetric outcomes of ART twins versus naturally conceived twins is discussed in this review. Methods to reduce the risk of multiple births including elective single embryo transfer and multifetal pregnancy reduction are also discussed.

Accuracy of assisted reproductive technology information on birth certificates: Florida and Massachusetts, 2004-06

BACKGROUND

Assisted Reproductive Technology (ART) includes fertility procedures where both egg and sperm are handled in the lab. ART use has increased considerably in recent years, accounting for 47,090 livebirths in the U.S. in 2010. ART increases the probability of multiple gestation births, which are at higher risks than singletons for adverse outcomes. Additionally, ART is associated with a greater risk of complications during pregnancy, labour, and delivery, and increased risk of adverse perinatal outcomes in singleton births.

METHODS

We merged Florida and Massachusetts birth records from 2004-06 with the National ART Surveillance System (NASS) and using NASS as the gold standard, calculated sensitivity, specificity, and positive predictive value (PPV) of ART reporting on the birth certificates by maternal, infant, and hospital characteristics. We fit random-effects logistic regression models to evaluate simultaneously the association of ART reporting with these predictors while accounting for correlation among births occurring in the same hospital.

RESULTS

Sensitivity of ART reporting on the birth certificate was 28.9% in Florida and 41.4% in Massachusetts. Specificity was >99% in both states. PPV was 45.5% in Florida and 54.6% in Massachusetts. The odds of ART reporting varied by state and by several maternal and delivery characteristics including age, parity, history of fetal loss, plurality, race/Hispanic ethnicity, delivery payment source, pre-existing conditions, and complications during pregnancy or labour and delivery.

CONCLUSIONS

There was significant under-reporting of ART procedures on the birth certificates. Using data on ART births identified only from birth certificates yields a biased sample of the population of ART births.