The risks confronting twins: a national perspective

Understanding the effects of alcohol policies on treatment admissions and birth outcomes among young pregnant people

BACKGROUND

This study examines whether state-level alcohol policy types in the United States relate to substance use disorder treatment admissions and birth outcomes among young pregnant and birthing people.

METHODS

We used data from the Treatment Episode Data Set: Admissions (TEDS-A) and Vital Statistics birth data for 1992-2019. We examined 16 state-level policies, grouped into three types: youth-specific, general population, and pregnancy-specific alcohol policies. Using Poisson and logistic regression, we assessed policy effects for those under 21 (aged 15-20) and considered whether effects differed for those just over 21 (aged 21-24).

RESULTS

Youth-specific policies were not associated with treatment admissions or preterm birth. There were statistically significant associations between family exceptions to minimum legal drinking age (MLDA) policies and low birthweight, but findings were in opposite directions across possession-focused and consumption-focused (MLDA) policies and did not differentially apply to people 15-20 versus 21-24. Most pregnancy-specific policies were not associated with treatment admissions, and none were significantly associated with birth outcomes. A few general population policies were associated with improved birth outcomes and/or increased treatment admissions. Specifically, both government spirits monopolies and prohibitions of spirits and heavy beer sales in gas stations were associated with decreased low birthweight among people 15-20 and among people 21-24. Effects of Blood Alcohol Concentration (BAC) limits varied by age, with slight reductions in adverse birth outcomes among people 15-20, as BAC limits get stronger, but slight increases for those 21-24. Although treatment admissions rates across ages were similar when BAC limits were in place, treatment admissions were greater for pregnant people 21-24 than for 15-20 when there were no BAC limits.

CONCLUSIONS

General population policies also appear effective for reducing the adverse effects of drinking during pregnancy for young people, including those under 21. Policies that target people based on age or pregnancy status appear less effective.

Prevalence and adverse outcomes of twin pregnancy in Eastern Africa: a systematic review and meta-analysis

INTRODUCTION

Multiple pregnancies are much more common today than they were in the past. Twin pregnancies occur in about 4% of pregnancies in Africa. Adverse pregnancy outcome was more common in twin pregnancy than in singleton pregnancy. There is no pooled evidence on the burden and adverse pregnancy outcome of twin pregnancy in eastern Africa. Thus, this systematic review and meta-analysis were conducted to assess the prevalence and adverse pregnancy outcomes of twin pregnancies.

METHODS

This systematic review and meta-analysis covers published and unpublished studies searched from different databases (PubMed, CINAHL (EBSCO), EMBASE, DOAJ, Web of Sciences, MEDLINE, Cochrane Library, SCOPUS, Google Scholar, and Google search). Finally, 34 studies were included in this systematic review and meta-analysis. JBI checklist was used to assess the quality of included papers. Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were used. Data synthesis and statistical analysis were conducted using STATA Version 14 software. Heterogeneity and publication bias were assessed. A forest plot was used to present the pooled prevalence using the random effect model.

RESULTS

The prevalence of twin pregnancy in eastern Africa was 3% [95% CI: 2, 3]. The adverse pregnancy outcomes like neonatal intensive care unit admission (78%), low birth weight (44%), low APGAR score (33%), prematurity (32%), stillbirth (30%), neonatal mortality (12%) and maternal complications like hypertensive disorder of pregnancy (25%), postpartum hemorrhage (7%), Cesarean section (37%), premature rupture of membrane (12%) and maternal mortality are more common among twin pregnancy than singleton pregnancy.

CONCLUSION

One in every 33 children born a twin in east Africa; admission to neonatal intensive care unit, low birth weight, low APGAR score, prematurity, stillbirth, neonatal mortality and maternal complications are its associated adverse birth outcomes. Since twin pregnancy is a high-risk pregnancy, special care is needed during pregnancy, labor and delivery to reduce adverse pregnancy outcomes.

Investigating associations between maternal stress, smoking and adverse birth outcomes: evidence from the All Our Families cohort

BACKGROUND

Independently, active maternal and environmental tobacco smoke exposure and maternal stress have been linked to an increased risk of preterm birth and low birth weight. An understudied relationship is the potential for interactive effects between these risk factors.

METHODS

Data was obtained from the All Our Families cohort, a study of 3,388 pregnant women < 25 weeks gestation recruited from those receiving prenatal care in Calgary, Canada between May 2008 and December 2010. We investigated the joint effects of active maternal smoking, total smoke exposure (active maternal smoking plus environmental tobacco smoke) and prenatal stress (Perceived Stress Scale, Spielberger State-Trait Anxiety Inventory), measured at two time points (< 25 weeks and 34-36 weeks gestation), on preterm birth and low birth weight.

RESULTS

A marginally significant association was observed with the interaction active maternal smoking and Spielberger State-Trait Anxiety Inventory scores in relation to low birth weight, after imputation (aOR = 1.02, 95%CI: 1.00-1.03, p = 0.06). No significant joint effects of maternal stress and either active maternal smoking or total smoke exposure with preterm birth were observed. Active maternal smoking, total smoke exposure, Perceived Stress Scores, and Spielberger State-Trait Anxiety Inventory scores were independently associated with preterm birth and/or low birth weight.

CONCLUSIONS

Findings indicate the role of independent effects of smoking and stress in terms of preterm birth and low birthweight. However, the etiology of preterm birth and low birth weight is complex and multifactorial. Further investigations of potential interactive effects may be useful in helping to identify women experiencing vulnerability and inform the development of targeted interventions.

Relationship between mandatory warning signs for cannabis use during pregnancy policies and birth outcomes in the Western United States

As U.S. states legalize recreational cannabis, some enact policies requiring Mandatory Warning Signs for cannabis during pregnancy (MWS-cannabis). While previous research has found MWS for alcohol during pregnancy (MWS-alcohol) associated with increases in adverse birth outcomes, research has not examined effects of MWS-cannabis. This study uses Vital Statistics birth certificate data from June 2015 - June 2017 in seven western states and policy data from NIAAA's Alcohol Policy Information System and takes advantage of the quasi-experiment created by Washington State's enactment of MWS-cannabis in June 2016, while nearby states did not. Outcomes are birthweight, low birthweight, gestation, and preterm birth. Analyses use a Difference-in-Difference approach and compare changes in outcomes in Washington to nearby states in the process of legalizing recreational cannabis (Alaska, California, Nevada) and, as a secondary analysis, nearby states continuing to criminalize recreational cannabis (Idaho, Montana, Wyoming). Birthweight was -7.03 g lower (95% CI -10.06, -4.00) and low birthweight 0.3% higher (95% CI 0.0, 0.6) when pregnant people were exposed to MWS-cannabis than when pregnant people were not exposed to MWS-cannabis, both statistically significant (p = 0.005 and p = 0.041). Patterns for gestation, -0.014 weeks earlier (95% CI -0.038, 0.010) and preterm birth 0.2% higher (95% CI -0.2, 0.7), were similar, although not statistically significant (p = 0.168 and 0.202). The direction of findings was similar in secondary analyses, although statistical significance varied. Similar to MWS-alcohol, enacting MWS-cannabis is associated with an increase in adverse birth outcomes. The idea that MWS-cannabis provide a public health benefit is not evidence-based.

Delivery timing in dichorionic diamniotic twin pregnancies complicated by preeclampsia: a decision analysis

OBJECTIVE

To determine the optimal timing of delivery in Dichorionic-diamniotic (DCDA) pregnancies complicated by preeclampsia without severe features.

METHODS

A decision-analytic model was created to compare outcomes of expectant management vs. delivery from 34 to 37w0d. Outcomes included quality-adjusted life years (QALYs), development of severe preeclampsia, maternal mortality, maternal stroke, small for gestational age (SGA) due to fetal growth restriction (FGR) detected antenatally, stillbirth, cerebral palsy (CP), and neonatal mortality. Probabilities, utilities, and life expectancies were derived from the literature. Univariate analysis was used to evaluate the impact of delivery at various gestational ages. Maternal and neonatal outcomes were calculated for a theoretical cohort of 10,000 DCDA pregnancies with preeclampsia.

RESULTS

The optimal gestational age for delivery was 36w0d when the total QALYs (868,112) were highest. Delivery at 34w0d resulted in the fewest cases of severe preeclampsia, maternal mortality, and maternal stroke (0, 4, and 15 cases per 10,000, respectively). The incidence of each of these adverse outcomes increased with gestational age, with the greatest number of adverse outcomes at 37w0d (2452 cases of severe preeclampsia, eight maternal deaths, and 31 cases of maternal stroke per 10,000). Delivery at 34w0d resulted in the fewest cases of severe preeclampsia (0), maternal stroke (15), maternal mortality (4), stillbirth (0), and SGA (1183). However, this strategy was also associated with most cases of neonatal CP (91) and neonatal mortality (87).

CONCLUSION

DCDA twin pregnancies complicated by preeclampsia without severe features appear to have the best outcomes when delivered at 36w0d. Specifically, when compared to delivery at 37w0d, this strategy reduced maternal and neonatal morbidity and mortality.

Methods for Monitoring Risk of Hypoxic Damage in Fetal and Neonatal Brains: A Review

Fetal, perinatal, and neonatal asphyxia are vital health issues for the most vulnerable groups in human beings, including fetuses, newborns, and infants. Severe reduction in oxygen and blood supply to the fetal brain can cause hypoxic-ischemic encephalopathy (HIE), leading to long-term neurological disorders, including mental impairment and cerebral palsy. Such neurological disorders are major healthcare concerns. Therefore, there has been a continuous effort to develop clinically useful diagnostic tools for accurately and quantitatively measuring and monitoring blood and oxygen supply to the fetal and neonatal brain to avoid severe consequences of asphyxia HIE and neonatal encephalopathy. Major diagnostic technologies used for this purpose include fetal heart rate monitoring, fetus scalp blood sampling, ultrasound imaging, magnetic resonance imaging, X-ray computed tomography, and nuclear medicine. In addition, given the limitations and shortcomings of traditional diagnostic methods, emerging technologies such as near-infrared spectroscopy and photoacoustic imaging have also been introduced as stand-alone or complementary solutions to address this critical gap in fetal and neonatal care. This review provides a thorough overview of the traditional and emerging technologies for monitoring fetal and neonatal brain oxygenation status and describes their clinical utility, performance, advantages, and disadvantages.

Association of parental prepregnancy BMI with neonatal outcomes and birth defect in fresh embryo transfer cycles: a retrospective cohort study

Background

Parental body mass index (BMI) is associated with pregnancy outcomes. But the effect of parental prepregnancy BMI on offspring conceived via in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI), especially the birth defect, remains to be determined. This study aimed to investigate the associations of parental prepregnancy BMI with neonatal outcomes and birth defect in fresh embryo transfer cycles.

Methods

We conducted a retrospective cohort study including 5741 couples in their first fresh IVF/ICSI cycles admitted to Women’s Hospital, School of Medicine, Zhejiang University from January 2013 to July 2016. The primary outcome was birth defects, which was classified according to the International Classification of Diseases, 10th Revision. Secondary outcomes included preterm delivery rate, infant gender, birth weight, small-for-gestational age (SGA) and large-for-gestational age (LGA). Multilevel regression analyses were used to assess the associations of parental prepregnancy BMI with neonatal outcomes and birth defect.

Results

In singletons, couples with prepregnancy BMI ≥25 kg/m² had higher odds of LGA than those with BMI < 25 kg/m². The birth defect rate was significantly higher when paternal prepregnancy BMI ≥25 kg/m² in IVF cycles (aOR 1.82, 95% CI 1.06–3.10) and maternal BMI ≥25 kg/m² in ICSI cycles (aOR 4.89, 95% CI 1.45–16.53). For subcategories of birth defects, only the odds of congenital malformations of musculoskeletal system was significantly increased in IVF offspring with paternal BMI ≥25 kg/m² (aOR 4.55, 95% CI 1.32–15.71). For twins, there was no significant difference among four groups, except for the lower birth weight of IVF female infants.

Conclusions

Parental prepregnancy BMI ≥25 kg/m² is associated with higher incidence of LGA in IVF/ICSI singletons. Paternal prepregnancy BMI ≥25 kg/m² was likely to have higher risk of birth defect in IVF offspring than those with BMI < 25 kg/m², particularly in the musculoskeletal system. It is essential for overweight or obesity couples to lose weight before IVF/ICSI treatments.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-021-04261-y.

Maternal weight gain and pregnancy outcomes in twin gestations

BACKGROUND

Data on the optimal gestational weight gain in twin pregnancies are limited. As a result, the Institute of Medicine currently provides only provisional recommendations on gestational weight gain in this population.

OBJECTIVE

This study aimed to identify the optimal range of gestational weight gain in twin pregnancies and to estimate the association between inappropriate gestational weight gain and adverse pregnancy outcomes.

STUDY DESIGN

This was a retrospective cohort study of all women with twin pregnancies that were followed up in a single, tertiary center between 2000 and 2014. We used 2 approaches to identify the optimal range of gestational weight gain: a statistical approach (the interquartile range of gestational weight gain in low-risk pregnancies with normal outcomes) and an outcome-based approach (by identifying thresholds of gestational weight gain below or above which the rate of adverse outcomes increases). The primary outcome was preterm birth. Associations of gestational weight gain below or above the normal range with the study outcomes were estimated using logistic regression analysis and were expressed as adjusted odds ratio with 95% confidence intervals. These associations were stratified by prepregnancy body mass index group.

RESULTS

A total of 1274 women with twin pregnancies met the study criteria: 43 were classified as underweight, 777 were normal weight, 278 were overweight, and 176 were obese. Our estimates of the optimal gestational weight gain range were similar to those recommended by the Institute of Medicine except for the obese category, in which our optimal gestational weight gain range at 37 weeks (9.3-16.3 kg) was lower than in the provisional Institute of Medicine recommendations (11.3-19.1 kg). Nearly half of our cohort experienced inappropriate gestational weight gain: 30% (n=381) gained weight below and 17% (n=216) gained weight above current Institute of Medicine recommendations. In the normal weight group, gestational weight gain below recommendations was associated with an increased risk of preterm birth and birthweight at the <10th centile and with a reduction in the risk of hypertensive disorders, whereas gestational weight gain above recommendations was associated with an increased risk of hypertensive disorders and a reduction in the risk of birthweight at the <10th centile. Associations were less consistent in the overweight and obese groups.

CONCLUSION

These findings identify gestational weight gain as a potentially modifiable risk factor for preterm birth and other pregnancy complications in twin gestations. Further prospective studies are needed to determine whether interventions aimed at optimizing gestational weight gain can improve the outcomes of these high-risk pregnancies.

Multiple births and low birth weight: Evidence from South Korea

OBJECTIVE

The proportion of multiple births has risen rapidly worldwide. Multiple births are likely to affect birth weight, which results in low birth weight (LBW) of less than 2500 g, possibly, because multiples are more likely to be born prematurely or less than 37 weeks into pregnancy. Using data from South Korea, this study aims to estimate the contribution of the rise in multiples to the rise in LBW incidence.

METHODS

Based on data from 2000 to 2017, we estimated the effect of multiples on LBW rates using linear regression analysis. Based on the regression analysis and the change in the proportion of multiples during this period, we calculated the contribution of the rise in multiples to the rise in LBW incidence using the total differential. In other words, we divided the change in LBW during the period due to the change in multiples by the total change during the period. The data are from the birth registry of the National Statistical Office, which contains information on the 8.4 million live births during the period 2000-2017.

RESULTS

We found that a 1 percentage point increase in multiples increases the proportion of LBWs by 0.495 percentage points. In addition, because the changes in the proportion of multiples and LBWs from 2000 to 2017 are 2.2 and 2.4 percentage points, respectively, 1.1 percentage points or 45.8% of the increase in LBWs over the period is due to the increase in multiples.

CONCLUSION

Since the Korean government introduced a measure to reduce the number of transferred embryos recently, one may expect that multiples in Korea would reduce in the near future, as it did in other countries. Subsequently, the incidence of LBW children is also likely to reduce, which is desirable in terms of the children's health outcomes.

Antepartum Fetal Surveillance: ACOG Practice Bulletin, Number 229

The goal of antepartum fetal surveillance is to reduce the risk of stillbirth. Antepartum fetal surveillance techniques based on assessment of fetal heart rate (FHR) patterns have been in clinical use for almost four decades and are used along with real-time ultrasonography and umbilical artery Doppler velocimetry to evaluate fetal well-being. Antepartum fetal surveillance techniques are routinely used to assess the risk of fetal death in pregnancies complicated by preexisting maternal conditions (eg, diabetes mellitus) as well as those in which complications have developed (eg, fetal growth restriction). The purpose of this document is to provide a review of the current indications for and techniques of antepartum fetal surveillance and outline management guidelines for antepartum fetal surveillance that are consistent with the best scientific evidence.

Optimal delivery timing for twin pregnancies: A population-based retrospective cohort study

AIMS

The optimal timing of delivery for twin pregnancies remains controversial. This study examined the risks of adverse neonatal outcomes and neonatal deaths according to gestational age at delivery in order to determine the optimal gestational age of delivery for twin pregnancies.

METHODS

This is a retrospective study of twin pregnancies delivered between 34 and 40 weeks of gestation from 1995 to 2000 in the United States. The primary outcomes evaluated were neonatal morbidity and mortality. The composite outcome of neonatal morbidity included the following variables: Apgar score lower than 7 at 5 minutes, assisted ventilation <30 minutes, assisted ventilation ≥30 minutes, hyaline membrane disease, meconium aspiration syndrome, neonatal seizures, birth injury, anaemia, and congenital malformations. Logistic regressions were applied to calculate adjusted odds ratios of the adverse outcomes according to the gestational week at delivery, with either individual twins or twin pairs as the unit of analysis.

RESULTS

A total of 466 038 twins from 233 019 pregnancies from the US National Center for Health Statistics matched the multiple birth data set included in the study. The composite neonatal morbidity and mortality risks declined from 34 to 38 weeks of gestation and increased thereafter in both individual and pair twins stratified analyses. Amongst neonatal adverse outcomes, the risk of low Apgar score and hyaline membrane disease decreased progressively towards 38 weeks of gestation, only to increase again towards 40 weeks. The risk of meconium aspiration syndrome increased after 38 weeks, in both individual and pair twins. There were no differences in the risk of birth injury and neonatal seizures when stratified by gestational age.

CONCLUSIONS

The optimal timing for twin delivery appears to be at 38 weeks of gestation, although individual maternal, foetal, and pregnancy characteristics should be considered when determining the best timing for delivery.

Fetal Growth Restriction: ACOG Practice Bulletin, Number 227

Fetal growth restriction, also known as intrauterine growth restriction, is a common complication of pregnancy that has been associated with a variety of adverse perinatal outcomes. There is a lack of consensus regarding terminology, etiology, and diagnostic criteria for fetal growth restriction, with uncertainty surrounding the optimal management and timing of delivery for the growth-restricted fetus. An additional challenge is the difficulty in differentiating between the fetus that is constitutionally small and fulfilling its growth potential and the small fetus that is not fulfilling its growth potential because of an underlying pathologic condition. The purpose of this document is to review the topic of fetal growth restriction with a focus on terminology, etiology, diagnostic and surveillance tools, and guidance for management and timing of delivery.

Microwave ablation versus radiofrequency ablation for the treatment of severe complicated monochorionic pregnancies in China：protocol for a pilot randomised controlled trial

INTRODUCTION

Complicated monochorionic twin pregnancies are often associated with high perinatal morbidity and mortality, some of which are severe enough to require a gestational reduction surgery to improve fetal survival and reduce disabilities. While radiofrequency ablation is currently the most commonly used procedure with higher fetal survival and fewer maternal and fetal complications compared with other surgical methods, the therapeutic effect of microwave ablation (MWA) is reported to be better, presumably due to the higher thermal effect and fewer restrictions. Currently there is limited evidence to prove the feasibility of MWA for selective reduction. The aim of this pilot study is to explore the feasibility, efficacy and safety of MWA reduction for severe complicated monochorionic pregnancies and may provide evidence for using the MWA in intrauterine surgeries extensively.

METHODS AND ANALYSIS

This is a study protocol for a parallel-design pilot randomised controlled trial. 60 eligible patients with severe complicated monochorionic pregnancies will be randomised in a ratio of 1:1 to MWA group and radiofrequency group. Patients will be followed up until 6 months of age of the retained fetal. The primary analysis will compare the rates of neonatal survival at 28 days to evaluate the effect of MWA. The study will also evaluate the safety profile of MWA including the occurrence of postoperative adverse events and maternal and fetal complications. Additional secondary outcomes to be explored include the condition of neonatal asphyxia and the growth of surviving fetus at 6 months. Outcomes will be analysed by both a frequentist and the Bayesian statistical approach.

ETHICS AND DISSEMINATION

This study was approved by the ethical review committee of the Peking University Third Hospital (Beijing, China). The results of this study will be published in peer-reviewed scientific journals and presented at relevant academic conferences.

TRIAL REGISTRATION NUMBER

NCT04014452; Pre-results.

Racial differences in the relationship between alcohol/pregnancy policies and birth outcomes and prenatal care utilization: A legal epidemiology study

OBJECTIVES

State policies regarding alcohol use during pregnancy (alcohol/pregnancy policies) have been in effect for more than 40 years. Previous research finds some policies increase adverse birth outcomes and decrease prenatal care utilization. This research examines whether effects of alcohol/pregnancy policies vary by race; the general hypothesis is that health benefits of policies are concentrated among White women and health harms of policies are concentrated among Black women.

METHODS

This study uses 1972-2015 Vital Statistics data and policy data from NIAAA's Alcohol Policy Information System and original legal research. The dataset includes more than 150 million singleton births. Outcomes are preterm birth (PTB), low birthweight (LBW), and prenatal care utilization. Logistic regression models include raceXpolicy interaction terms as main predictors, adjust for individual- and state-level controls, include fixed effects for state, year and state-specific time trends, and account for clustering by state.

RESULTS

The impact of alcohol/pregnancy policies varied by race for preterm birth, varied in a few cases for low birthweight, and generally did not vary for prenatal care utilization. The hypothesis regarding the direction of differential effects was not supported. Six policies had an adverse impact on PTB and/or LBW for White women. Findings differed for Black women; for Black women, four policies had a beneficial impact for PTB and one had an adverse impact for LBW.

CONCLUSIONS

The impact of alcohol/pregnancy policies on birth outcomes varies by race. Future research should explore why some policies appear to have opposite effects for White v. Black women.

Costs associated with policies regarding alcohol use during pregnancy: Results from 1972-2015 Vital Statistics

BACKGROUND AND OBJECTIVE

As of 2016, 43 US states have policies regarding alcohol use during pregnancy. A recent study found that out of eight state-level alcohol/pregnancy policies, six are significantly associated with poorer birth outcomes, and two are not associated with any outcomes. Here we estimate the excess numbers of low birthweight (LBW) and preterm births (PTB) related to these policies and their associated additional costs in the first year of life.

METHODS

Cost study using birth certificate data for 155,446,714 singleton live births in the United States between 1972-2015. Exposures were state- and month/year-specific indicators of having each of eight alcohol/pregnancy policies in place. Outcomes were excess numbers of LBW and PTB and associated costs in the first year of life. Fixed effects regressions with state-specific time trends were used for statistical analyses in 2018.

RESULTS

In 2015, policies mandating warning signs were associated with an excess of 7,375 LBW; policies defining alcohol use during pregnancy as child abuse/neglect were associated with an excess of 12,372 PTB; these excess adverse outcomes are associated with additional costs of $151,928,002 and $582,698,853 in the first year of life, respectively.

CONCLUSIONS

Multiple state-level alcohol pregnancy policies lead to increased prevalence of LBW and PTB, which cost hundreds of millions of dollars annually. Policymakers should consider adverse public health impacts of alcohol/pregnancy policies before expanding extant policies to new substances or adopting existing policies in new states.

The relationship between maternal body mass index and pregnancy outcomes in twin compared with singleton pregnancies

OBJECIVE

Women with twins have an a priori increased risk for many of the complications associated with maternal obesity. Thus, the impact of maternal obesity in twins may differ from that reported in singletons. In addition, given the increased metabolic demands in twin pregnancies, the impact of maternal underweight may be greater in twin compared with singleton gestations. Our objective was to test the hypothesis that the relationship between maternal pre-pregnancy body mass index (BMI) and adverse pregnancy outcomes differ between twin and singleton gestations.

METHODS

This was a retrospective population-based study of all women who had a singleton or twin hospital birth in Ontario, Canada, between April 2012 and March 2016. Data were obtained from the Better Outcomes Registry & Network (BORN) Ontario. The relationship between maternal BMI category and pregnancy complications was assessed separately in twin and singleton gestations. The primary outcome was a composite variable that included any of the following complications: preeclampsia, gestational diabetes, or preterm birth before 32^0/7 weeks. Relative risk (aRR) and 95% confidence intervals (CI) for adverse outcomes for each BMI category as defined by WHO (using normal weight category as reference) were generated using modified Poisson regression, adjusting for maternal age, nulliparity, smoking, previous preterm birth, and fetal sex.

RESULTS

A total of 487,870 women with singleton (n = 480,010) and twin (n = 7860) pregnancies met the inclusion criteria. The risk of the composite primary outcome, preeclampsia, gestational diabetes, and cesarean delivery increased with high maternal BMI in both singleton and twin gestations, but these associations were weaker in twin compared with singleton gestations (association of BMI ≥ 40.0 kg/m² with primary outcome: aRR = 3.10, 95%-CI 2.96-3.24 in singletons compared with aRR = 1.74, 95%-CI 1.37-2.20 in twins). In singleton pregnancies the risk of preterm birth at < 32^0/7 weeks increased with maternal BMI, mainly due to an increased risk of provider-initiated preterm birth. In twin gestations, however, underweight (but not overweight or obesity) was associated with the greatest risk of preterm birth at < 32 weeks (aRR 1.67, 95%-CI 1.17-2.37), mainly due to an increased risk of spontaneous preterm birth (aRR 2.10, 95%-CI 1.44-3.08).

CONCLUSION

In healthy women with twin pregnancies, underweight is associated with the greatest risk for preterm birth, while the association of maternal obesity with adverse pregnancy outcomes is weaker than that observed in singletons.

Do day-3 embryo grade predict day-5 blastocyst transfer outcomes in patients with good prognosis?

The main aim was to investigate whether or not day-3 embryo grade could predict day-5 blastocyst transfer outcomes in patients with good prognosis. This study included 233 elective single blastocyst transfers (eSBT) by D5 selection with conventional morphology (CM) and 121 elective single blastocyst transfers (eSBT) by D5 selection with time-lapse monitoring system (TL) from October 2016 to October 2017. All the patients were submitted to controlled ovarian stimulation (COS) with long-term protocol and transferred for the first time. The main outcome measures were clinical pregnancy rates (CPR) and ongoing pregnancy (OPR). Our results suggested that CPR (58.04 versus 57.89 versus 55.56%; p = .957) and OPR (66.07 versus 65.79 versus 64.44%; p = .981) were comparable among day 3 grades I, grades II, and grades III groups. We also observed that the TL group showed a slightly better CPR and OPR than CM group (p > .05). Our findings suggested that good or poor embryos at day-3 were not predictive of the outcomes of good-quality blastocysts in a good-prognosis population. It needed to be emphasized that time-lapse monitoring might be useful for elective single blastocyst transfer.

Umbilical Cord Coiling in High-risk Pregnancies: Associations With Determinants of Adverse Birth Outcomes and Iron Status

Abnormal umbilical cord coiling has been associated with adverse neonatal outcomes, but the etiology of these findings remains poorly characterized. This study was undertaken to examine associations between cord coiling and maternal iron (Fe) status and to identify potential determinants of hypo- and hypercoiling in 2 higher risk obstetric groups: pregnant adolescents (≤18 years, n = 92) and adult women carrying twins (n = 49), triplets (n = 11), or quadruplets (n = 1). Umbilical cords were classified as hypo-, normo-, or hypercoiled using digital photographs to assess gross appearance. Hypocoiling and hypercoiling were observed in 44% (n = 86/195) and 13% (n = 26/195) of the combined study population. The prevalence of hypocoiling among women carrying multiples was over 3-fold higher than the prevalence in singleton pregnancies based on the published data. Within the entire study population, hypocoiling was associated with a lower gestational age at birth when compared to normocoiling and hypercoiling (36.3 ± 3.6 weeks [n = 86] vs 37.8 ± 2.7 [n = 83], P < .01, and 38.2 ± 2.6 [n = 26], P < .01, respectively), whereas hypercoiling was associated with significantly lower serum ferritin when compared to normocoiling ( P < .01) and hypocoiling ( P < .001). In the multiples cohort only, hypercoiling was significantly associated with multiparity ( P < .01) and lower birth weight ( P < .05). Further studies are needed to identify the determinants and consequences of cord coiling.

Associations Between State-Level Policies Regarding Alcohol Use Among Pregnant Women, Adverse Birth Outcomes, and Prenatal Care Utilization: Results from 1972 to 2013 Vital Statistics

BACKGROUND

Policies regarding alcohol use during pregnancy continue to be enacted and debated in the United States. However, no study to date has examined whether these policies are related to birth outcomes-the outcomes they ultimately aim to improve. Here, we assessed whether state-level policies targeting alcohol use during pregnancy are related to birth outcomes, which has not been done comprehensively before.

METHODS

The study involved secondary analyses of birth certificate data from 148,048,208 U.S. singleton births between 1972 and 2013. Exposures were indicators of whether the following 8 policies were in effect during gestation: Mandatory Warning Signs (MWS), Priority Treatment for Pregnant Women, Priority Treatment for Pregnant Women/Women with Children, Reporting Requirements for Data and Treatment Purposes, Prohibitions Against Criminal Prosecution, Civil Commitment, Reporting Requirements for Child Protective Services Purposes, and Child Abuse/Child Neglect. Outcomes were low birthweight (<2,500 g), premature birth (<37 weeks), any prenatal care utilization (PCU), late PCU, inadequate PCU, and normal (≥7) APGAR score. Multivariable fixed-effect logistic regressions controlling for both maternal- and state-level covariates were used for statistical analyses.

RESULTS

Of the 8 policies, 6 were significantly related to worse outcomes and 2 were not significantly related to any outcomes. The policy requiring MWS was related to the most outcomes: specifically, living in a state with MWS was related to 7% higher odds of low birthweight (p < 0.001); 4% higher odds of premature birth (p < 0.004); 18% lower odds of any PCU (p < 0.001); 12% higher odds of late PCU (p < 0.002); and 10% lower odds of a normal APGAR score (p < 0.001) compared to living in a state without MWS.

CONCLUSIONS

Most policies targeting alcohol use during pregnancy do not have their intended effects and are related to worse birth outcomes and less PCU.

Management of fetal growth restriction using the contraction stress test: a case-control study

Purpose: Fetal growth restriction (FGR) is a concerning health issue. However, studies on FGR management are limited due to its rarity. We aimed to evaluate the efficacy of the contraction stress test (CST) for FGR management. Materials and methods: A case-control retrospective study design. Our institute innovated CST in FGR management in 2017. We included women in their 33rd-40th week of pregnancy with a diagnosis of FGR and retrospectively divided them into groups: the CST group (FGR management with CST) and no CST group (FGR management without CST) before and after CST development. Neonatal outcome, pH, and pO₂ of umbilical artery (UA) were compared between the two groups. Results: No significant differences in the rate of birth weight, Apgar score <7 (5 minutes), neonatal death, hospitalization to newborn childhood intensive care unit (NICU), and UA pH were found between groups. Average UA pH was 7.29 ± 0.05 and 7.29 ± 0.04 in the CST and no CST groups, respectively (p = .864). Average UA pO₂ values were 21.1 ± 8.6 and 15.7 ± 5.0 mmHg in the CST and no CST groups, respectively (p = .016), showing significant differences. Conclusions: Neonatal outcomes and UA pH were slightly different between the groups managed with and without CST. However, UA pO₂ values significantly differed between the groups. For FGR management, the use of a CST may allow for early intervention before fetal acidemia and acidosis. For establishing the effects of a CST for FGR management, analysis including several cases and investigation of long-term outcomes of newborn infants is necessary.

Comparison of conventional 2D ultrasound to magnetic resonance imaging for prenatal estimation of birthweight in twin pregnancy

BACKGROUND

During prenatal follow-up of twin pregnancies, accurate identification of birthweight and birthweight discordance is important to identify the high-risk group and plan perinatal care. Unfortunately, prenatal evaluation of birthweight discordance by 2-dimensional ultrasound has been far from optimal.

OBJECTIVE

The objective of the study was to prospectively compare estimates of fetal weight based on 2-dimensional ultrasound (ultrasound-estimated fetal weight) and magnetic resonance imaging (magnetic resonance-estimated fetal weight) with actual birthweight in women carrying twin pregnancies.

STUDY DESIGN

Written informed consent was obtained for this ethics committee-approved study. Between September 2011 and December 2015 and within 48 hours before delivery, ultrasound-estimated fetal weight and magnetic resonance-estimated fetal weight were conducted in 66 fetuses deriving from twin pregnancies at 34.3-39.0 weeks; gestation. Magnetic resonance-estimated fetal weight derived from manual measurement of fetal body volume. Comparison of magnetic resonance-estimated fetal weight and ultrasound-estimated fetal weight measurements vs birthweight was performed by calculating parameters as described by Bland and Altman. Receiver-operating characteristic curves were constructed for the prediction of small-for-gestational-age neonates using magnetic resonance-estimated fetal weight and ultrasound-estimated fetal weight. For twins 1 and 2 separately, the relative error or percentage error was calculated as follows: (birthweight - ultrasound-estimated fetal weight (or magnetic resonance-estimated fetal weight)/birthweight) × 100 (percentage). Furthermore, ultrasound-estimated fetal weight, magnetic resonance-estimated fetal weight, and birthweight discordance were calculated as 100 × (larger estimated fetal weight-smaller estimated fetal weight)/larger estimated fetal weight. The ultrasound-estimated fetal weight discordance and the birthweight discordance were correlated using linear regression analysis and Pearson's correlation coefficient. The same was done between the magnetic resonance-estimated fetal weight and birthweight discordance. To compare data, the χ², McNemar test, Student t test, and Wilcoxon signed rank test were used as appropriate. We used the Fisher r-to-z transformation to compare correlation coefficients.

RESULTS

The bias and the 95% limits of agreement of ultrasound-estimated fetal weight are 2.99 (-19.17% to 25.15%) and magnetic resonance-estimated fetal weight 0.63 (-9.41% to 10.67%). Limits of agreement were better between magnetic resonance-estimated fetal weight and actual birthweight as compared with the ultrasound-estimated fetal weight. Of the 66 newborns, 27 (40.9%) were of weight of the 10th centile or less and 21 (31.8%) of the fifth centile or less. The area under the receiver-operating characteristic curve for prediction of birthweight the 10th centile or less by prenatal ultrasound was 0.895 (P < .001; SE, 0.049), and by magnetic resonance imaging it was 0.946 (P < .001; SE, 0.024). Pairwise comparison of receiver-operating characteristic curves showed a significant difference between the areas under the receiver-operating characteristic curves (difference, 0.087, P = .049; SE, 0.044). The relative error for ultrasound-estimated fetal weight was 6.8% and by magnetic resonance-estimated fetal weight, 3.2% (P < .001). When using ultrasound-estimated fetal weight, 37.9% of fetuses (25 of 66) were estimated outside the range of ±10% of the actual birthweight, whereas this dropped to 6.1% (4 of 66) with magnetic resonance-estimated fetal weight (P < .001). The ultrasound-estimated fetal weight discordance and the birthweight discordance correlated significantly following the linear equation: ultrasound-estimated fetal weight discordance = 0.03 + 0.91 × birthweight (r = 0.75; P < .001); however, the correlation was better with magnetic resonance imaging: magnetic resonance-estimated fetal weight discordance = 0.02 + 0.81 × birthweight (r = 0.87; P < .001).

CONCLUSION

In twin pregnancies, magnetic resonance-estimated fetal weight performed immediately prior to delivery is more accurate and predicts small-for-gestational-age neonates significantly better than ultrasound-estimated fetal weight. Prediction of birthweight discordance is better with magnetic resonance imaging as compared with ultrasound.

Intrauterine Growth Restriction. Guideline of the German Society of Gynecology and Obstetrics (S2k-Level, AWMF Registry No. 015/080, October 2016)

AIMS

The aim of this official guideline published and coordinated by the German Society of Gynecology and Obstetrics (DGGG) was to provide consensus-based recommendations obtained by evaluating the relevant literature for the diagnostic treatment and management of women with fetal growth restriction.

METHODS

This S2k guideline represents the structured consensus of a representative panel of experts with a range of different professional backgrounds commissioned by the Guideline Committee of the DGGG.

RECOMMENDATIONS

Recommendations for diagnostic treatment, management, counselling, prophylaxis and screening are presented.

Population-based birth weight reference percentiles for Chinese twins

BACKGROUND

Birth weight percentiles by gestational age are important for assessing prenatal growth and predicting postnatal outcomes of newborns. Several countries have developed nation-specific birth weight references for twins, but China still lacks such references.

METHODS AND RESULTS

Birth weight data for twins born between October 2006 and September 2015 were abstracted from the China National Population-based Birth Defects Surveillance System. A total of 54,786 live twin births aged ≥28 weeks of gestation without birth defects were included in the analysis. The LMS method was adopted to generate gestational age-specific birth weight percentiles and curves for male and female twins separately. Significant differences were observed between the current reference and other references developed for Chinese or non-Chinese twins. The neonatal mortality rate in this cohort was 12.3‰, and much higher rates at very early gestation weeks were identified in small-for-gestational-age twins grouped by the newly developed reference cutoffs.

CONCLUSIONS

The established birth weight centiles represent the first birth weight norm for contemporary Chinese twins and can be a useful tool to assess growth of twins in clinical and research settings. Key Messages There have been no population-based birth weight percentiles for Chinese twins prior to this study. The established birth weight centiles for female and male twins are markedly lower than those for Chinese singletons. Twin-specific curves should be used for determining inappropriate for gestational age in twins rather than using existing singleton reference. The birth weight percentiles for twins differed significantly from those for non-Chinese twins. In addition to ethnic influences, the observed differences could be ascribed to variations in prenatal care, fetal or maternal nutrition status or other environmental factors. Neonatal mortality rates varied considerably among twins grouped by the newly developed reference percentiles. Small-for-gestational-age twins had much higher mortality than did appropriate-for-gestational-age twins, highlighting the need to reduce postnatal mortality by improving perinatal health care for twins.

Transferring two grades I cleavage-stage embryo might not be a good protocol

PURPOSE

The aim of this study was to explore whether transferring two grades I cleavage-stage embryo was suitable for the patients in the first fresh transfer.

METHODS

This study included 202 single grades I cleavage-stage, 229 single grades III cleavage-stage, 743 single excellent blastocyst, 522 double grades I cleavage-stage, and 596 double grades III cleavage-stage embryo transfers. Main clinical outcomes: clinical pregnancy and twin-pregnancy rate.

RESULTS

Among single excellent blastocyst, single grades I and single grades III group, the clinical pregnancy rate was significantly higher in single excellent blastocyst group than single grades I and grades III group (67.16% versus 42.08% versus 23.97%; p < 0.001). When transferred double grades I cleavage-stage embryos, the clinical pregnancy rate reached 68.20% which was no significant difference compared with the single excellent blastocyst group (67.16%). However, the twin-pregnancy rate was significantly higher in double grades I group than double grades III and single excellent blastocyst group (43.26% versus 26.70% versus 0.60%; p < 0.001).

CONCLUSIONS

Because of higher twin-pregnancy incidence rate, transferring two grades I cleavage-stage embryo might not be a good protocol. Extended culture to blastocyst-stage could be considered for the patient with only two grades I cleavage-stage embryos.

Lower perinatal mortality in preterm born twins than in singletons: a nationwide study from The Netherlands

BACKGROUND

Twin pregnancies are at increased risk for perinatal morbidity and death because of many factors that include a high incidence of preterm delivery. Compared with singleton pregnancies, overall perinatal risk of death is higher in twin pregnancies; however, for the preterm period, the perinatal mortality rate has been reported to be lower in twins.

OBJECTIVE

The purpose of this study was to compare perinatal mortality rates in relation to gestational age at birth between singleton and twin pregnancies, taking into account socioeconomic status, fetal sex, and parity.

STUDY DESIGN

We studied perinatal mortality rates according to gestational age at birth in 1,502,120 singletons pregnancies and 51,658 twin pregnancies without congenital malformations who were delivered between 2002 and 2010 after 28 weeks of gestation. Data were collected from the nationwide Netherlands Perinatal Registry.

RESULTS

Overall the perinatal mortality rate in twin pregnancies (6.6/1000 infants) was higher than in singleton pregnancies (4.1/1000 infants). However, in the preterm period, the perinatal mortality rate in twin pregnancies was substantially lower than in singleton pregnancies (10.4 per 1000 infants as compared with 34.5 per 1000 infants, respectively) for infants who were born at <37 weeks of gestation; this held especially for antepartum deaths. After 39 weeks of gestation, the perinatal mortality rate was higher in twin pregnancies. Differences in parity, fetal sex, and socioeconomic status did not explain the observed differences in outcome.

CONCLUSION

Overall the perinatal mortality rate was higher in twin pregnancies than in singleton pregnancies, which is most likely caused by the high preterm birth rate in twins and not by a higher mortality rate for gestation, apart from term pregnancies. During the preterm period, the antepartum mortality rate was much lower in twin pregnancies than in singleton pregnancies. We suggest that this might be partially due to a closer monitoring of twin pregnancies, which indirectly suggests a need for closer surveillance of singleton pregnancies.

The effect on pregnancy and multiples of transferring 1-3 embryos in women at least 40 years old

PURPOSE "CAPSULE" IS MANDATORY. PLEASE PROVIDE.SINGLE EMRBYO TRANSFER (SET) IN WOMEN ≥40 YEARS OLD APPEARS TO LOWER THE CHANCE OF A PREGNANCY. HOWEVER, IT MINIMIZES THE RISK OF MULTIPLE PREGNANCIES EVEN IN WOMEN OF ADVANCED MATERNAL AGE. THEREFORE, WOMEN 40 YEARS OF AGE OR OLDER SHOULD BE OFFERED (SET).: This study was performed to investigate the multiple pregnancies and live birth rates when 1-3 embryos are transferred at this age in women at least 40 years of age.

METHOD

A retrospective analysis of data which included 631 women aged 40 to 46 years, who underwent 901 cycles of IVF, from August 2010 to June 2012 was undertaken. These women underwent embryo transfer of 1-3 non-donor fresh embryo(s).

RESULTS

Results suggested that the average pregnancy rate when up to three embryos were transferred was 25 % for women 40 years old, 20 % for women 41 years old, 16 % for women 42 years old, 17 % for women 43 years old, 8 % for women 44 years old, 6 % for women 45 years old, and 0 % for women 46 years old. No live births occurred in women treated after their 44th birthday, and only patients younger than 42 years of age receiving double embryo transfer had a live birth of twins. Live birth rates increased as more embryos were transferred for 40- and 42-year-old subjects (p = 0.01 and 0.05, respectively).

CONCLUSIONS

From these results, it was concluded that SET in women ≥40 years old appears to lower the chance of a pregnancy. However, it minimizes the risk of multiple pregnancies even in women of advanced maternal age. Women 40 years of age or older should be offered single-embryo transfer. Further studies are needed to determine risk of multiple pregnancies in women 42 years of age or older when few embryos are transferred. Decisions on the number of embryos to transfer should be on a case by case basis, in discussion with the patient.

A Case of Delayed Interval Delivery with a Successful Hospital Move

This report is the first case of delayed interval twin delivery in which the first infant and mother survived without major morbidity following transport to another facility. In addition, this case is only the second report of asynchronous delivery in which both twins survived and neither suffered any major morbidity. A 30-year-old G5P1031 African American female with a diamniotic/dichorionic twin pregnancy presented to U.S. Naval Hospital Okinawa, Japan, at 22 + 5 weeks due to vaginal bleeding. At 23 + 2 weeks, Twin A was born secondary to advanced cervical dilation. Twin A's birth weight was 650 g with APGAR scores of 6 (1 min) and 7 (5 min). Following delivery of Twin A, Placenta A was left in utero with high ligation of the umbilical cord. Due to a scheduled hospital move, the mother and Twin A were transported to the new facility at Camp Foster. Three weeks later, Twin B was delivered at 26 + 4 weeks. Twin B's birth weight was 930 g with APGAR scores of 3 (1 min) and 7 (5 min). Both twins were discharged without IVH, PVL, ROP, or CLD. This case demonstrates the possibility of transporting both the mother and surviving infant A to a higher level of care prior to delivery of subsequent fetuses.

Growth parameters of discordant preterm twins during the first year of life

OBJECTIVE

To evaluate and compare growth parameters (weight, length and head circumference) of discordant preterm twins during the first year of life.

METHODS

Retrospective data were collected on 78 pairs of >10% discordant preterm twins. Data regarding short-term neonatal outcome were recorded. Growth parameters were recorded at birth and again at 1 year of age, as collected by phone interview.

RESULTS

At 1 year of age, the gap was significantly reduced between the group of smaller twins and the group of larger twins on all the parameters studied. Discordance in weight decreased from a mean of 22% at birth (calculated from the weight of the larger twin) to 8.9%, in length from 6.5% to 2.5% and in head circumference from 5.5% to 1.3% at 1 year of age. While length and head circumference (HC) z-scores improved in both the large and the small siblings, weight z-score decreased significantly among the large twins and decreased mildly among the small twins.

CONCLUSIONS

The gaps in growth parameters between the smaller twins of preterm discordant twins and their larger siblings are significantly reduced during the first year of life. The impact of the differential growth patterns between the two siblings should be further evaluated.

Perinatal outcomes of multiple-gestation pregnancies in Kenya, Zambia, Pakistan, India, Guatemala, and Argentina: a global network study

AIM

To determine the rates of multiple gestation, stillbirth, and perinatal and neonatal mortality and to determine health care system characteristics related to perinatal mortality of these pregnancies in low- and middle-income countries.

METHODS

Pregnant women residing within defined geographic boundaries located in six countries were enrolled and followed to 42 days postpartum.

RESULTS

Multiple gestations were 0.9% of births. Multiple gestations were more likely to deliver in a health care facility compared with singletons (70 and 66%, respectively, p < 0.001), to be attended by skilled health personnel (71 and 67%, p < 0.001), and to be delivered by cesarean (18 versus 9%, p < 0.001). Multiple-gestation fetuses had a relative risk (RR) for stillbirth of 2.65 (95% confidence interval [CI] 2.06, 3.41) and for perinatal mortality rate (PMR) a RR of 3.98 (95% CI 3.40, 4.65) relative to singletons (both p < 0.0001). Neither delivery in a health facility nor the cesarean delivery rate was associated with decreased PMR. Among multiple-gestation deliveries, physician-attended delivery relative to delivery by other health providers was associated with a decreased risk of perinatal mortality.

CONCLUSIONS

Multiple gestations contribute disproportionately to PMR in low-resource countries. Neither delivery in a health facility nor the cesarean delivery rate is associated with improved PMR.

Utilizing twins as controls for non-twin case-materials in genome wide association studies

Twin registries around the globe have collected DNA samples from large numbers of monozygotic and dizygotic twins. The twin sample collections are frequently used as controls in disease-specific studies together with non-twins. This approach is unbiased under the hypothesis that twins and singletons are comparable in terms of allele frequencies; i.e. there are no genetic variants associated with being a twin per se. To test this hypothesis we performed a genome-wide association study comparing the allele frequency of 572,352 single nucleotide polymorphisms (SNPs) in 1,413 monozygotic (MZ) and 5,451 dizygotic (DZ) twins with 3,720 healthy singletons. Twins and singletons have been genotyped using the same platform. SNPs showing association with being a twin at P-value < 1 × 10^-5 were selected for replication analysis in 1,492 twins (463 MZ and 1,029 DZ) and 1,880 singletons from Finland. No SNPs reached genome-wide significance (P-value < 5 × 10^-8) in the main analysis combining MZ and DZ twins. In a secondary analysis including only DZ twins two SNPs (rs2033541 close to ADAMTSL1 and rs4149283 close to ABCA1) were genome-wide significant after meta-analysis with the Finnish population. The estimated proportion of variance on the liability scale explained by all SNPs was 0.08 (P-value=0.003) when MZ and DZ were considered together and smaller for MZ (0.06, P-value=0.10) compared to DZ (0.09, P-value=0.003) when analyzed separately. In conclusion, twins and singletons can be used in genetic studies together with general population samples without introducing large bias. Further research is needed to explore genetic variances associated with DZ twinning.

Perinatal outcome of monochorionic in comparison to dichorionic twin pregnancies

OBJECTIVE

The aim of this study is to compare the neonatal outcomes of monochorionic and dichorionic twin pregnancies.

METHODS

A retrospective cohort study involving 51 twin pregnancies followed and delivered at Sultan Qaboos University Hospital was conducted between January 2006 and December 2011.

RESULT

Thirty six (71%) pregnancies were dichorionic diamniotic (DCDA), 14 (27%) were monochorionic diamniotic (MCDA), and one (2%) was monochorionic monoamniotic (MCMA). The antepartum complications noted in the 15 monochorionic twins were discordant fetal growth in 2 (14%) cases, low birth weight in 11 (73%) babies, pre-eclampsia in three mothers (21%) and twin to twin transfusion syndrome in four (29%) cases. Fetal respiratory distress affected eight (57%) of the pregnancies. Six (40%) twin sets were delivered before 30 weeks, 4 (27%) sets at 31 to 32 weeks, 2 (13%) sets at 34-35 weeks, 2 (13%) sets at 36-37 weeks, and 1 (7%) at 37-38 weeks. Fifteen mothers delivered 16 live infants, 9 (30%) stillbirths and 5 (17%) died after birth. Most neonatal deaths were due to neonatal sepsis and pulmonary hypoplasia. Dichorioinic twins, (DC) morbidity was seen in 11% and 40% for monochoroinic twins (MC). Mortality rate was 17% for DC and 47% for MC twins.

CONCLUSIONS

Perinatal morbidity and mortality remain high among monochorionic twins. This is likely due to frequent twin-to-twin transfusion syndrome, prematurity, fetal growth restriction and intrauterine fetal death. Improved fetal and neonatal management may result in improved outcomes.

Delayed interval delivery of a second twin after the preterm labor of the first one in twin pregnancies: delayed delivery in twin pregnancies

A diamnionic dichorionic twin pregnant women (due to in vitro fertilization) admitted to emergency department at the 21st week of gestation because of regular contractions. By gynecological examination, we observed 8 cm dilated cervix with 80% effacement. Amniotic membrane was also bulging through the cervix. After evaluation delivery of the presenting fetus occurred quickly. The baby's weight was 610 gr and no heart activity was detected. Placenta of the first fetus expulsed immediately. We decided to retain the second fetus to allow the improvement in the outcome. McDonald cerclage was performed and the patient treated with tocolytics and antibiotics, and she was continuously monitored up to the 28th week of pregnancy. After she was discharged in the 28th week, she was controlled weekly in obstetrics clinic. At the 36th gestational week which was 101 days after the cerclage procedure, 3639 g male fetus was delivered with cesarean section and had an uneventful neonatal course. Delayed-interval delivery is useful and acceptable therapeutic option for the management of the remaining fetus in twin pregnancies even after the expulsion of the placenta. Antibiotic and tocolytic administration with cervical cerclage application can be associated with longer interdelivery interval.

A Comparison of Educational Achievement in a National Sample of Dutch Female Twins and Their Matched Singleton Controls

The aim of this study was to compare the educational achievement of female twins (n = 577) and their matched singleton controls (n = 447), who were selected from participants of a national test of educational achievement in the years 1993 to 1998. To assure the representativeness of the selected groups we also compared the achievement scores of the twins and the controls to those of the total Dutch female population tested in the same period. We analyzed the results of the following educational achievement scales: Language, Mathematics and Information Processing. The results indicated that the singleton classmates performed significantly better than the twins on all three scales. However, the twins performed equally well as compared to the Dutch female population. We believe that our singleton control group was not as properly selected as we intended, a selection bias operative at the level of the schools may have confounded the comparison. We therefore conclude on the basis of a comparison with the performance of the total Dutch female population that there are no differences in educational achievement between female twins and singletons.

Evaluating 2 Year Outcome in Twins ≤ 30 Weeks Gestation at Birth: A Regional Perinatal Unit's Experience

With improved technology in assisted reproductive medicine, there has been an absolute increase in the numbers of twin pregnancies with an associated increase in perinatal mortality and morbidity. This increase in perinatal mortality and morbidity is largely due to a higher incidence of delivering preterm as compared to singletons. Twin pregnancies have their unique complications that include abnormal placental communication and discordant growth which are associated with perinatal mortality and morbidity. The objectives of this study were two-fold: i) to determine if the morbidity/mortality outcome at 18–24 months corrected age seen in a cohort of twins born between 24–30 weeks gestation was significantly different as compared to singleton preterm infants of the same gestation; and ii) to determine and evaluate any differences between monochorionic (MC) and dichorionic (DC) twins. Twins 24–30 weeks gestation at birth born between 01/01/97–30/06/99 were identified and prospectively followed to 18–24 months corrected age (c.a.). They were matched with a singleton infant of the same gender and within 1 week of the same gestation. Obstetrical, neonatal and neurodevelopmental data were gathered and analyzed. The primary outcome was death or the presence of a severe neurodevelopmental deficit at 18–24 months corrected age. Of the 56 sets of twins identified, 52 sets were followed prospectively with 101 infants available for matching. In this cohort, twin pregnancies had a lower incidence of pregnancy-induced hypertension and premature rupture of membranes than singletons (p < 0.05). The two groups were comparable in neonatal characteristics. The incidence of death or severe disability was 29.7% in twins vs. 22.8% in singletons (p = 0.337, Fisher's exact test). The major area of deficit was in the cognitive category for both groups, 9.9% vs. 7.9% respectively. MC twins made up 35.6%; DC twins 64.4%. Twin to twin transfusion syndrome (TTTS) occurred in 6.9%. Discordant growth occurred more frequently in MC pregnancies (p = 0.016). MC twins tended to be more premature, lower in birth weight, and experience neonatal morbidity in the form of patent ductus arteriosus and sepsis (p < 0.05) as compared to DC twins. However, the primary outcome of death or severe neurodevelopmental deficit at 18–24 months c.a. was not significantly different between the two groups, 38.9% (MC) vs. 24.6% (DC), (p = 0.173, Fisher's exact test). Neurodevelopmental morbidity or mortality in twins with TTTS was 42%. Mortality and severe neurodevelopmental morbidity were not significantly higher in twins as compared to singletons in this cohort. However, the trend is slightly higher in twins, which may have clinical significance. Though not statistically significant, the incidence of 38.9% in adverse outcome with MC twins may be clinically significant. With the number of twins steadily increasing, further monitoring is required to determine future directions in intervention and research. Early recognition of monochorionicity remains essential to optimize care and neurodevelopment for these infants.

The Natural Course of Monochorionic and Dichorionic Twin Pregnancies: A Historical Cohort

Current early diagnosis, surveillance and intervention options make it hard to determine the natural course of twin pregnancies, especially regarding spontaneous preterm delivery and perinatal mortality. We studied the natural course in monochorionic (MC) and dichorionic (DC) twin pregnancies in a historical cohort. Twin pregnancies were studied in a unique database of 651 twin pairs born in the period 1907 to 1938. We examined the effect of chorionicity on gestational age, birthweight, peri-natal mortality, intertwin birthweight differences, the incidence of preeclampsia and maternal mortality. Perinatal mortality was 27.7% for MC and 15.8% for DC twins (p < .001). Gestational age and birthweight were stronger predictors of perinatal mortality than chorionicity. Perinatal outcome was poorer for the second twin, especially in DC twins. Delivery before 37 weeks of gestation occurred more often in MC twin pregnancies (48.8% compared to 33.3% in DC twin pregnancies). DC twins were on average 288 g (95% confidence interval 201–376) heavier than MC twins. Severe birthweight discordancy occurred equally in MC and DC twins (18.1%). However, if present, mortality was only increased in MC twins. The birthweight of girls was not affected by the presence of a male co-twin. In this historical cohort MC twin pregnancies had a higher perinatal mortality, caused by a high incidence of low birthweight mainly due to preterm delivery. Mortality did not differ in deliveries after 31 weeks of gestation, which is in contrast to recent data. Apparently, modern obstetrics is more effective in reducing mortality in DC twins.

Pregnancy Outcome of Monochorionic Twins: Does Amnionicity Matter?

Objective: To compare the fetal loss rate of monochorionic (MC) twin pregnancies according to their amnionicity. Methods: A retrospective review of all MC pregnancy outcomes in a tertiary centre. Pregnancy outcomes were compared for monochorionic monoamniotic (MCMA) versus monochorionic diamniotic (MCDA) pregnancies. Results: 29 MCMA and 117 MCDA twin pregnancies were identified. The overall fetal loss rate was significantly higher in MCMA (23/52, 44.2%) compared to MCDA pregnancies (28/233, 12%, Chi squared = 30.03, p < .001). Kaplan-Meier analysis showed that fetal survival rate in MCDA twins were significantly higher than in MCMA twins (Log-rank Chi-squared = 27.9, p < .0005). Early pregnancy ultrasound identified the causes for these fetal losses in some MCMA twins. After exclusion of identifiable causes, the difference in fetal survival was not significant in the two groups (Log-rank chi-squared = 0.373, p = .54). Conclusion: The loss rate for MCMA twins is high and occurs mainly due to discordant congenital abnormality, conjoint twins or twin reversed arterial perfusion (TRAP) sequence. Although the fetal loss rate in MCDA is lower than in MCMA pregnancies, the majority of fetal loss in MCDA pregnancies cannot be predicted at the first scan at presentation. The data of this study questions the widespread policy of a difference in the scheduling of elective delivery for MCMA and MCDA twins.

Age-Related Success with Elective Single versus Double Blastocyst Transfer

Background. Although the optimal outcome of assisted reproductive technology (ART) is a healthy singleton pregnancy, the rate of twin gestation from ART in women over the age of 35 is persistently high. Methods/Findings. We compared clinical pregnancy rates (PRs), ongoing pregnancy/live birth rates, and multiple gestation rates (MGRs) in 108 women who chose elective single blastocyst transfer (eSBT) to 415 women who chose elective double blastocyst transfer (eDBT) at a hospital-based IVF center. There was no significant difference in PR between eSBT and eDBT (57.4% versus 50.2%, P = 0.47) nor between eSBT and eDBT within each age group: <35, 35–37, 38–40, and >40. The risk of multiple gestations, however, was greatly increased between eSBT and eDBT (1.6 versus 32.4%, P < 0.00005), and this difference did not vary across age groups. Conclusion(s). Women undergoing eDBT are at uniformly high risk of multiple gestation regardless of age. eSBT appears to significantly lower the risk of multiple gestation without compromising PR.

Timing delivery of the growth-restricted fetus

Intrauterine growth restriction (IUGR) is commonly defined as an estimated fetal weight of less than the 10th percentile. While 70% of these are small for normal reasons and not at risk, 30% are pathologically small at risk for numerous complications including fetal death. In the late preterm IUGR fetus (>34 weeks), prematurity risks less and the risk of fetal demise becomes the primary concern. Pulsed-wave Doppler interrogation of the umbilical and middle cerebral artery is useful in reducing perinatal mortality, however, Doppler changes in these vessels of the IUGR fetus may not occur after 34 weeks gestation. There are no randomized trials addressing the timing of delivery of the IUGR fetus in the late preterm or early-term period. However, retrospective reports show an increase risk of fetal demise. While timing the delivery of the late preterm/early-term IUGR fetus requires consideration of multiple factors (e.g. degree of growth restriction, etiology, amniotic fluid volume, and biophysical and Doppler testing), available data suggests that delivery should occur by 37 to 38 weeks for singleton IUGR fetuses. In twin pregnancies with a co-twin IUGR fetus, chorionicity also impacts timing of delivery, but delivery should occur by 34-36 weeks.

Genetics and developmental pathology of twinning

Twin pregnancy is associated with a high risk of congenital malformations. This review covers the risk of such anomalies in both dizygotic and monozygotic twin pregnancies, and discusses current insights into the associations relating to zygosity, chorionicity and genetic factors. The pathological basis of specific malformations unique to the monochorionic twinning process, including conjoined twinning and twin reversed arterial perfusion (TRAP) sequence, is discussed in more detail, and factors contributing to the higher perinatal mortality rate in multiple pregnancies are addressed.

The impact of fetal gender on prematurity in dichorionic twin gestations after in vitro fertilization

BACKGROUND

Impact of fetal gender on prematurity has been primarily investigated in singleton pregnancies. In an attempt to understand better how fetal gender may affect gestational length in twin gestations after in vitro fertilization, same-sex twins and opposite twins were compared for pregnancy duration.

METHODS

This study evaluated 113 women at ages 20 to 39 years with consecutive dichorionic-diamniotic twin gestations after assisted reproduction. All pregnancies were results of fresh in vitro fertilization (IVF) cycles with use of autologous oocytes and sperm and were delivered at up to 37 weeks of gestation at a University-based high-risk, maternal-fetal medicine unit.

RESULTS

Both groups did not differ in baseline characteristics, such as maternal ages, indications for fertility treatments, number of previous IVF attempts, body mass index and parity. Opposite sex- twins, however, presented with significantly shorter gestational age at birth (32.9 +/- 3.4 weeks) than same-sex twins (34.3 +/- 2.5 weeks), (p < 0.05). Younger maternal age was also associated with shorter pregnancy duration (p < 0.05).

CONCLUSIONS

Fetal gender mix serves as risk factor for more significant prematurity in dichorionic-diamniotic twins after assisted reproduction with opposite sex twins at higher risk than same sex-twins.

Are there differences in brain morphometry between twins and unrelated singletons? A pediatric MRI study

Twins provide a unique capacity to explore relative genetic and environmental contributions to brain development, but results are applicable to non-twin populations only to the extent that twin and singleton brains are alike. A reason to suspect differences is that as a group twins are more likely than singletons to experience adverse prenatal and perinatal events that may affect brain development. We sought to assess whether this increased risk leads to differences in child or adolescent brain anatomy in twins who do not experience behavioral or neurological sequelae during the perinatal period. Brain MRI scans of 185 healthy pediatric twins (mean age = 11.0, SD = 3.6) were compared to scans of 167 age- and sex-matched unrelated singletons on brain structures measured, which included gray and white matter lobar volumes, ventricular volume, and area of the corpus callosum. There were no significant differences between groups for any structure, despite sufficient power for low type II (i.e. false negative) error. The implications of these results are twofold: (1) within this age range and for these measures, it is appropriate to include healthy twins in studies of typical brain development, and (2) findings regarding heritability of brain structures obtained from twin studies can be generalized to non-twin populations.

Correlates of negative and positive mood state in mothers of twins

Relationships between parenting distress, social support, and sense of competence and negative and positive maternal mood were assessed in 162 mothers with twins younger than 2 years. Women with lower satisfaction scores on the sense of competence scale reported higher negative mood (adjusted R(2) = 21.7%, p < .001). Women with lower parenting distress and higher efficacy scores on the sense of competence scale reported higher positive mood (adjusted R(2) = 39.4%, p < .001). Neither instrumental nor subjective social support contributed to variance in maternal mood. Interventions should be aimed at decreasing parenting distress and increasing sense of competence for mothers of twins.

Monochorionic twins in which at least one fetus has a congenital heart disease with or without twin-twin transfusion syndrome

AIMS

To review the course of monochorionic (MC) twin gestations in which one or both fetuses were diagnosed with congenital heart disease (CHD) and to identify clinical characteristics regarding the related intrauterine environmental factors particularly associated with non-twin-twin transfusion syndrome (TTTS).

METHODS

This study is a review of a two-center experience of MC twin pregnancies with CHD born between 2000 and 2006.

RESULTS

There were 87 MC twin pregnancies of which 11 were associated with fetal heart disease. We found concordance of CHD in 2 of the 11 twin sets. Among all of the discordant cases, the size of the affected twin was smaller. TTTS was observed in one case associated with CHD; in this case the donor twin had a coarctation of the aorta. Abnormal cord insertion was observed in 9 (69%) out of the 13 affected infants, and a significant relation was found between the presence of CHD and abnormal cord insertion.

CONCLUSIONS

Of the MC twins, the smaller seemed more likely to be affected by primary structural cardiac anomalies. CHD in MC twins is possibly related to an abnormal cord insertion. Further studies are warranted to determine whether a causal relationship exists.

The association of crown-rump length discordance in twin gestations with adverse perinatal outcomes

OBJECTIVE

The purpose of this study was to evaluate the association between the crown-rump length (CRL) difference in twin gestations and adverse pregnancy outcome.

STUDY DESIGN

Women with a first trimester ultrasound scan of a twin pregnancy who delivered between June 2000 and March 2006 at Northwestern Memorial Hospital were identified. The association between the difference in CRLs and pregnancy outcomes was explored.

RESULTS

For the 178 twins who were eligible for the study, the median difference in CRLs was 4.2% and the median difference in birthweights was 9.3%. Twins with a CRL difference of >85th percentile (11.1%) were more likely to have discordant birthweights and to have at least 1 of the pair be small-for-gestational age, be admitted to the special care nursery, and have perinatal morbidity.

CONCLUSION

CRL differences of >85th percentile are associated with several measures of adverse perinatal outcome.

Medicolegal issues in multiple pregnancy

Any discussion of multiple pregnancy figures prominently in the consideration of the medicolegal aspects of placental pathology. Multiple gestations are common and becoming more so with assisted reproductive techniques, and multiples are associated with a disproportionate share of complications that may result in disputes over quality of care. Higher rates of intrauterine growth retardation, prematurity, stillbirth, morbidity, mortality, cerebral palsy, anomalous development, and malformation as compared with singletons are well documented in multiple pregnancy and should be anticipated. Monochorionic placentation and complications of vascular anastomosis are important factors contributing to poor outcome. Other factors, although occurring in all gestations, are relevant because they are more common in multiple gestations.