Validation of infertility treatment and assisted reproductive technology use on the birth certificate in eight states

Infertility treatments and cyanotic congenital heart defects among livebirths in the USA: findings from a contemporary cohort

STUDY QUESTION

Is there an elevated risk of cyanotic congenital heart defects (CCHD) among livebirths following infertility treatments?

SUMMARY ANSWER

In this population-based study of single livebirths, infertility treatment (either ART or non-ART) was associated with a higher prevalence of CCHD among livebirths.

WHAT IS KNOWN ALREADY

The use of infertility treatment has been on the rise over the past few decades. However, there are limited studies assessing the risk of major cardiac defects following infertility treatments.

STUDY DESIGN, SIZE, DURATION

A retrospective cohort study of livebirth data from the National Vital Statistics System (NVSS) was conducted, comprising of 9.6 million singleton livebirths among first-time mothers aged 15-49 years from 2016 to 2022.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Information on infertility treatment use and CCHD was obtained from the health and medical information section of birth certificates, which was completed by healthcare staff after reviewing medical records. Logistic regression models were used to estimate odds ratios (OR) and 95% CI. Entropy balancing weighting analysis and probabilistic bias analysis were also performed.

MAIN RESULTS AND THE ROLE OF CHANCE

The proportion of births following infertility treatment increased from 1.9% (27 116) to 3.1% (43 510) during the study period. Overall, there were 5287 cases of CCHD resulting in a prevalence of 0.6 per 1000 livebirths. The prevalence was 1.2 per 1000 live births among infertility treatment users (ART: 1.1 per 1000 livebirths; non-ART: 1.3 per 1000 livebirths) while that for naturally conceived births was 0.5 per 1000 livebirths. Compared to naturally conceived births, the use of any infertility treatment (OR: 2.06, 95% CI: 1.82-2.33), either ART (OR: 2.02, 95% CI: 1.73-2.36) or other infertility treatments (OR: 2.12, 95% CI: 1.74-2.33), was associated with higher odds of CCHD after adjusting for maternal and paternal age, race and ethnicity, and education, as well as maternal nativity, marital status, source of payment, smoking status, and pre-pregnancy measures of BMI, hypertension and diabetes. This association did not differ by the type of infertility treatment (ART versus other infertility treatments) (OR: 1.04, 95% CI: 0.82-1.33, P = 0.712), and was robust to the presence of exposure and outcome misclassification bias and residual confounding.

LIMITATIONS, REASONS FOR CAUTION

The findings are only limited to livebirths. We did not have the capacity to examine termination data, but differential termination by mode of conception has not been supported by previous studies designed to consider it. Infertility treatment use was self-reported, leading to the potential for selection bias and misclassification for infertility treatment and CCHD. However, the association persisted when systematic bias as well as exposure and outcome misclassification bias were accounted for in the analyses. Information on the underlying etiology of infertility relating to either maternal, paternal, or both factors, data on specific types of ART and other infertility treatments, as well as information on subtypes of CCHD, were all not available.

WIDER IMPLICATIONS OF THE FINDINGS

In light of the increasing trend in the use of infertility treatment in the USA, and elsewhere, the finding of the current study holds significant importance for the clinical and public health of reproductive-aged individuals. The data show that the use of infertility treatment may expose offspring to elevated odds of severe congenital heart defects such as CCHD studied here. These findings cannot be interpreted causally. While our findings can assist in preconception counseling and prenatal care for pregnancies conceived by either ART or other infertility treatments, they also support some current recommendations that pregnancies resulting from infertility treatments undergo fetal echocardiography screening.

STUDY FUNDING/COMPETING INTEREST(S)

No funding was sought for the study. The authors declare that they have no conflict of interest.

TRIAL REGISTRAION NUMBER

N/A.

Infertility treatment is associated with increased risk of postpartum hospitalization due to heart disease

BACKGROUND

Cardiovascular disease is a major cause of maternal mortality, but the extent to which infertility treatment is implicated in heart disease remains unclear.

OBJECTIVE

To evaluate the association between infertility treatment and postpartum heart disease.

METHODS

We designed a retrospective cohort study of patients who delivered in the United States between 2010 and 2018. The primary outcome was hospitalization within 12-month post-delivery due to heart disease (including ischemic heart disease, atherosclerotic heart disease, cardiomyopathy, hypertensive disease, heart failure, and cardiac dysrhythmias). We estimated the rate difference (RD) of hospitalizations among patients who conceived with infertility treatment and those who conceived spontaneously. Associations were expressed as hazard ratios (HRs) and 95% confidence intervals (CIs), derived from Cox proportional hazards regression after adjustment for potential confounders.

RESULTS

Infertility treatment was recorded in 0.9% (n = 287,813) of 31,339,991 deliveries. Rates of heart disease hospitalizations with infertility treatment and with spontaneous conception were 550 and 355 per 100,000, respectively (RD 195, 95% CI: 143-247; adjusted HR 1.99, 95% CI: 1.80-2.20). The most important increase in risk was observed for hypertensive disease (adjusted HR 2.16, 95% CI: 1.92-2.42). This increased risk was apparent as early as 30-day post-delivery (HR 1.61, 95% CI: 1.39-1.86), with progressively increasing risk up to a year.

CONCLUSIONS

Although the absolute risk of postpartum heart disease hospitalization is low, infertility treatment is associated with an increased risk, especially for hypertensive disease. These findings highlight the importance of timely postpartum follow-ups in patients who received infertility treatment.

Gestational diabetes mellitus in pregnancies conceived after infertility treatment: a population-based study in the United States, 2015-2020

Objective

To evaluate the risk of gestational diabetes mellitus (GDM) in singleton pregnancies conceived using infertility treatment and examine the influence of race and ethnicity as well as prepregnancy body mass index (BMI).

Design

Cross-sectional study using the US vital records data of women that delivered singleton births.

Setting

United States, 2015-2020.

Interventions

Any infertility treatment was divided into two groups: those that used fertility-enhancing drugs, artificial insemination, or intrauterine insemination, and those that used assisted reproductive technology (ART).

Main Outcome Measuress

Gestational diabetes mellitus, defined as a diagnosis of diabetes mellitus during pregnancy, includes both diet-controlled GDM and medication-controlled GDM in singleton pregnancies conceived with infertility treatment or spontaneously and delivered between 20- and 44-weeks' gestation. We also examined whether the infertility treatment-GDM association was modified by maternal race and ethnicity as well as prepregnancy BMI. Associations were expressed as a rate ratio (RR) and 95% confidence interval (CI), derived from log-linear models after adjustment for potential confounders.

Results

A total of 21,943,384 singleton births were included, with 1.5% (n = 318,086) undergoing infertility treatment. Rates of GDM among women undergoing infertility treatment and those who conceived spontaneously were 11.0% (n = 34,946) and 6.5% (n = 1,398,613), respectively (adjusted RR 1.24, 95% CI 1.23, 1.26). The RRs were adjusted for maternal age, parity, education, race and ethnicity, smoking, BMI, chronic hypertension, and year of delivery. The risk of GDM was modestly increased for those using fertility-enhancing drugs (adjusted RR 1.28, 95% CI 1.27, 1.30) compared with ART (adjusted RR 1.18, 95% CI 1.17, 1.20), and this risk was especially apparent for non-Hispanic White women (adjusted RR 1.29, 95% CI 1.26, 1.31) and Hispanic women (adjusted RR 1.35, 95% CI 1.29, 1.41). The number of women who needed to be exposed to infertility treatment to diagnose one case of GDM was 46. Prepregnancy BMI did not modify the infertility treatment-GDM association overall and within strata of race and ethnicity. These general patterns were stronger after potential corrections for misclassification of infertility treatment and unmeasured confounding.

Conclusions

Infertility treatment, among those who received fertility-enhancing drugs, is associated with an increased GDM risk. The persistently higher risk of GDM among women who seek infertility treatment, irrespective of prepregnancy weight classification, deserves attention. Infertility specialists must be vigilant with preconception counseling and ensure that all patients, regardless of race and ethnicity or BMI, are adequately tested for GDM early in pregnancy using a fasting blood glucose level or a traditional 50-g oral glucose tolerance test. Testing may be completed by the infertility specialist or deferred to the primary prenatal care provider at the first prenatal visit.

Risk of Stroke Hospitalization After Infertility Treatment

Importance

Stroke accounts for 7% of pregnancy-related deaths in the US. As the use of infertility treatment is increasing, many studies have sought to characterize the association of infertility treatment with the risk of stroke with mixed results.

Objective

To evaluate the risk of hospitalization from hemorrhagic and ischemic strokes in patients who underwent infertility treatment.

Design, Setting, and Participants

This population-based, retrospective cohort study used data abstracted from the Nationwide Readmissions Database, which stores data from all-payer hospital inpatient stays from 28 states across the US, from 2010 and 2018. Eligible participants included individuals aged 15 to 54 who had a hospital delivery from January to November in a given calendar year, and any subsequent hospitalizations from January to December in the same calendar year of delivery during the study period. Statistical analysis was performed between November 2022 and April 2023.

Exposure

Hospital delivery after infertility treatment (ie, intrauterine insemination, assisted reproductive technology, fertility preservation procedures, or use of a gestational carrier) or after spontaneous conception.

Main Outcomes and Measures

The primary outcome was hospitalization for nonfatal stroke (either ischemic or hemorrhagic stroke) within the first calendar year after delivery. Secondary outcomes included risk of stroke hospitalization at less than 30 days, less than 60 days, less than 90 days, and less than 180 days post partum. Cox proportional hazards regression models were used to estimate associations, which were expressed as hazard ratios (HRs), adjusted for confounders. Effect size estimates were corrected for biases due to exposure misclassification, selection, and unmeasured confounding through a probabilistic bias analysis.

Results

Of 31 339 991 patients, 287 813 (0.9%; median [IQR] age, 32.1 [28.5-35.8] years) underwent infertility treatment and 31 052 178 (99.1%; median [IQR] age, 27.7 [23.1-32.0] years) delivered after spontaneous conception. The rate of stroke hospitalization within 12 months of delivery was 37 hospitalizations per 100 000 people (105 patients) among those who received infertility treatment and 29 hospitalizations per 100 000 people (9027 patients) among those who delivered after spontaneous conception (rate difference, 8 hospitalizations per 100 000 people; 95% CI, -6 to 21 hospitalizations per 100 000 people; HR, 1.66; 95% CI, 1.17 to 2.35). The risk of hospitalization for hemorrhagic stroke (adjusted HR, 2.02; 95% CI, 1.13 to 3.61) was greater than that for ischemic stroke (adjusted HR, 1.55; 95% CI, 1.01 to 2.39). The risk of stroke hospitalization increased as the time between delivery and hospitalization for stroke increased, particularly for hemorrhagic strokes. In general, these associations became larger for hemorrhagic stroke and smaller for ischemic stroke following correction for biases.

Conclusions and Relevance

In this cohort study, infertility treatment was associated with an increased risk of stroke-related hospitalization within 12 months of delivery; this risk was evident as early as 30 days after delivery. Timely follow-up in the immediate days post partum and continued long-term follow-up should be considered to mitigate stroke risk.

Assisted reproductive technology and association with childhood cancer subtypes

OBJECTIVES

To investigate the association between assisted reproductive technology (ART) use and childhood cancer subtype.

STUDY DESIGN

We deployed a cross-sectional survey of 1701 parents of children with cancer about their ART use, demographics, and gestational and perinatal factors. Multivariable logistic regression modeled the association between ART use, birthweight and multiple gestation status with childhood cancer, by subtype.

RESULTS

ART use was highest among children with osteosarcoma relative to children with other cancer types, and this association was statistically significant in multivariable models (OR = 4.4; 95% CI = 1.7-11.3; p = 0.0020). ART use was also elevated among children with hepatoblastoma, but this relationship appeared to be due to the strong associations between ART use and lower birthweight in our sample. No specific ART modality appeared to drive these associations. In univariate models, multiple gestation was associated with a 2.7-fold increased odds of hepatoblastoma (OR = 2.71; 95% CI = 1.14-6.42; p = 0.02) and a 1.6-fold increased odds of neuroblastoma (OR = 1.62; 95% CI = 1.03-2.54; p = 0.03), but these associations were not retained in multivariable models.

CONCLUSIONS

Associations between ART use and hepatoblastoma risk may be attributable to birthweight, a known hepatoblastoma risk factor. ART use may also be associated with osteosarcoma, independent of birthweight, an association not previously observed in studies limited to cancers diagnosed before adolescence. Evaluating long-term health outcomes in children conceived by ART, throughout adolescence and potentially into adulthood, appears warranted.

The risks of birth defects and childhood cancer with conception by assisted reproductive technology

STUDY QUESTION

Is there an association between fertility status, method of conception and the risks of birth defects and childhood cancer?

SUMMARY ANSWER

The risk of childhood cancer had two independent components: (i) method of conception and (ii) presence, type and number of birth defects.

WHAT IS KNOWN ALREADY

The rarity of the co-occurrence of birth defects, cancer and ART makes studying their association challenging. Prior studies have indicated that infertility and ART are associated with an increased risk of birth defects or cancer but have been limited by small sample size and inadequate statistical power, failure to adjust for or include plurality, differences in definitions and/or methods of ascertainment, lack of information on ART treatment parameters or study periods spanning decades resulting in a substantial historical bias as ART techniques have improved.

STUDY DESIGN, SIZE, DURATION

This was a population-based cohort study linking ART cycles reported to the Society for Assisted Reproductive Technology Clinic Outcome Reporting System (SART CORS) from 1 January 2004 to 31 December 2017 that resulted in live births in 2004-2018 in Massachusetts and North Carolina and live births in 2004-2017 in Texas and New York. A 10:1 sample of non-ART births were chosen within the same time period as the ART birth. Non-ART siblings were identified through the ART mother's information. Children from non-ART births were classified as being born to women who conceived with ovulation induction or IUI (OI/IUI) when there was an indication of infertility treatment on the birth certificate, and the woman did not link to the SART CORS; all others were classified as being naturally conceived.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The study population included 165 125 ART children, 31 524 non-ART siblings, 12 451 children born to OI/IUI-treated women and 1 353 440 naturally conceived children. All study children were linked to their respective State birth defect registries to identify major defects diagnosed within the first year of life. We classified children with major defects as either chromosomal (i.e. presence of a chromosomal defect with or without any other major defect) or nonchromosomal (i.e. presence of a major defect but having no chromosomal defect), or all major defects (chromosomal and nonchromosomal), and calculated rates per 1000 children. Logistic regression models were used to generate adjusted odds ratios (AORs) and 95% CIs of the risk of birth defects by conception group (OI/IUI, non-ART sibling and ART by oocyte source and embryo state) with naturally conceived children as the reference, adjusted for paternal and maternal ages; maternal race and ethnicity, education, BMI, parity, diabetes, hypertension; and for plurality, infant sex and State and year of birth. All study children were also linked to their respective State cancer registries. Cox proportional hazards regression models were used to estimate hazard ratios (HRs) and 95% CIs of cancer by birth defect status (including presence of a defect, type and number of defects), and conception group.

MAIN RESULTS AND THE ROLE OF CHANCE

A total of 29 571 singleton children (2.0%) and 3753 twin children (3.5%) had a major birth defect (chromosomal or nonchromosomal). Children conceived with ART from autologous oocytes had increased risks for nonchromosomal defects, including blastogenesis, cardiovascular, gastrointestinal and, for males only, genitourinary defects, with AORs ranging from 1.22 to 1.85; children in the autologous-fresh group also had increased risks for musculoskeletal (AOR 1.28, 95% CI 1.13, 1.45) and orofacial defects (AOR 1.40, 95% CI 1.17, 1.68). Within the donor oocyte group, the children conceived from fresh embryos did not have increased risks in any birth defect category, whereas children conceived from thawed embryos had increased risks for nonchromosomal defects (AOR 1.20, 95% CI 1.03, 1.40) and blastogenesis defects (AOR 1.74, 95% CI 1.14, 2.65). The risk of cancer was increased among ART children in the autologous-fresh group (HR 1.31, 95% CI 1.08, 1.59) and non-ART siblings (1.34, 95% CI 1.02, 1.76). The risk of leukemia was increased among children in the OI/IUI group (HR 2.15, 95% CI 1.04, 4.47) and non-ART siblings (HR 1.63, 95% CI 1.02, 2.61). The risk of central nervous system tumors was increased among ART children in the autologous-fresh group (HR 1.68, 95% CI 1.14, 2.48), donor-fresh group (HR 2.57, 95% CI 1.04, 6.32) and non-ART siblings (HR 1.84, 95% CI 1.12, 3.03). ART children in the autologous-fresh group were also at increased risk for solid tumors (HR 1.39, 95% CI 1.09, 1.77). A total of 127 children had both major birth defects and cancer, of which 53 children (42%) had leukemia. The risk of cancer had two independent components: (i) method of conception (described above) and (ii) presence, type and number of birth defects. The presence of nonchromosomal defects increased the cancer risk, greater for two or more defects versus one defect, for all cancers and each type evaluated. The presence of chromosomal defects was strongly associated with cancer risk (HR 8.70 for all cancers and HR 21.90 for leukemia), further elevated in the presence of both chromosomal and nonchromosomal defects (HR 21.29 for all cancers, HR 64.83 for leukemia and HR 4.71 for embryonal tumors). Among the 83 946 children born from ART in the USA in 2019 compared to their naturally conceived counterparts, these risks translate into an estimated excess of 761 children with major birth defects, 31 children with cancer and 11 children with both major birth defects and cancer.

LIMITATIONS, REASONS FOR CAUTION

In the SART CORS database, it was not possible to differentiate method of embryo freezing (slow freezing versus vitrification), and data on ICSI were only available in the fresh embryo ART group. In the OI/IUI group, it was not possible to differentiate type of non-ART treatment utilized, and in both the ART and OI/IUI groups, data were unavailable on duration of infertility. Since OI/IUI is underreported on the birth certificate, some OI/IUI children were likely included among the naturally conceived children, which will decrease the difference between all the groups and the naturally conceived children.

WIDER IMPLICATIONS OF THE FINDINGS

The use of ART is associated with increased risks of major nonchromosomal birth defects. The presence of birth defects is associated with greater risks for cancer, which adds to the baseline risk in the ART group. Although this study does not show causality, these findings indicate that children conceived with ART, non-ART siblings, and all children with birth defects should be monitored more closely for the subsequent development of cancer.

STUDY FUNDING/COMPETING INTEREST(S)

This project was supported by grant R01 HD084377 from the National Institute of Child Health and Human Development. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institute of Child Health and Human Development, or the National Institutes of Health, nor any of the State Departments of Health which contributed data. M.L.E. reports consultancy for Ro, Hannah, Dadi, Sandstone and Underdog; presidency of SSMR; and SMRU board member. The remaining authors report no conflict of interest.

TRIAL REGISTRATION NUMBER

N/A.

Medically Assisted Reproduction Treatment Types and Birth Outcomes

Medically assisted reproduction treatments are associated with adverse birth outcomes; however, those risks are unlikely to be associated with the infertility treatments themselves.

OBJECTIVE:

To compare risks of adverse birth outcomes among pregnancies conceived with and without medically assisted reproduction treatments.

METHODS:

Birth certificates were used to study birth outcomes of all neonates born in Utah from 2009 through 2017. Of the 469,919 deliveries, 52.8% (N=248,013) were included in the sample, with 5.2% of the neonates conceived through medically assisted reproduction. The outcome measures included birth weight, gestational age, low birth weight (LBW, less than 2,500 g), preterm birth (less than 37 weeks of gestation), and small for gestational age (SGA, birth weight less than the 10th percentile). Linear models were estimated for the continuous outcomes (birth weight, gestational age), and linear probability models were used for the binary outcomes (LBW, preterm birth, SGA). First, we compared the birth outcomes of neonates born after medically assisted reproduction and natural conception in the overall sample (between-family analyses), before and after adjustment for parental background and neonatal characteristics. Second, we employed family fixed effect models to investigate whether the birth outcomes of neonates conceived through medically assisted reproduction differed from those of their naturally conceived siblings (within-family comparisons).

RESULTS:

Neonates conceived through medically assisted reproduction weighed less, were born earlier, and were more likely to be LBW, preterm, and SGA than neonates conceived naturally. More invasive treatments (assisted reproductive technology [ART] and artificial insemination [AI] or intrauterine insemination) were associated with worse birth outcomes; for example, the proportion of LBW and preterm birth was 6.1% and 7.9% among neonates conceived naturally and 25.5% and 29.8% among neonates conceived through ART, respectively. After adjustments for various neonatal and parental characteristics, the differences in birth outcomes between neonates conceived through medically assisted reproduction and naturally were attenuated yet remained statistically significant; for example, neonates conceived through ART were at 3.2 percentage points higher risk for LBW (95% CI 2.4–4.1) and 4.8 percentage points higher risk for preterm birth (95% CI 3.9–5.7). Among siblings, the differences in the frequency of adverse outcomes between neonates conceived through medically assisted reproduction and neonates conceived naturally were small and statistically insignificant for all types of treatments.

CONCLUSION:

Medically assisted reproduction treatments are associated with adverse birth outcomes; however, those risks are unlikely to be associated with the infertility treatments itself.

Infertility treatment and the risk of small for gestational age births: a population-based study in the United States

Objective

To evaluate the association between infertility treatments and small for gestational age (SGA) births.

Design

Cross-sectional study.

Setting

United States, 2015–2019.

Patient(s)

Women (n = 16,836,228) who delivered nonmalformed, singleton live births (24–44 weeks’ gestation).

Intervention(s)

Any infertility treatment, including assisted reproductive technology (ART) and prescribed fertility-enhancing medications.

Main Outcome Measure(s)

Small for gestational age birth, defined as sex-specific birth weight <10% for gestational age. Associations between SGA and infertility treatment were derived from Poisson regression with robust variance. Risk ratios (RR) and 95% confidence intervals (CI) were derived after adjusting for confounders. In a sensitivity analysis, we corrected for nondifferential exposure misclassification and unmeasured confounding biases.

Result(s)

Subsequently, 1.4% (n = 231,177) of pregnancies resulted from infertility treatments (0.8% ART and 0.6% fertility-enhancing medications). Of these, SGA births occurred in 9.4% (n = 21,771) and 11.9% (n = 1,755,925) of pregnancies conceived with infertility treatment and naturally conceived pregnancies, respectively (adjusted RR, 1.07; 95% CI, 1.06, 1.08). However, after correction for misclassification bias and unmeasured confounding, infertility treatment was associated with a 27% reduced risk of SGA (bias-corrected RR, 0.73; 95% CI, 0.53, 0.85). Similar trends were seen for analyses stratified by exposure to ART and fertility-enhancing medications, as well as for SGA <5th and <3rd percentiles.

Conclusion(s)

Exposure to infertility treatment is associated with a reduced risk of SGA births. These findings, which are contrary to some published reports, may reflect changes in the modern practice of infertility care, maternal lifestyle, and compliance with prenatal care within the infertile population. Until these findings are corroborated, the associations must be cautiously interpreted.

Singleton pregnancies conceived with infertility treatments and the risk of neonatal and infant mortality

OBJECTIVES

To examine the risks of neonatal and infant mortality in relation to infertility treatment and to quantify the extent to which preterm delivery mediates this relationship.

DESIGN

Cross-sectional study.

SETTING

United States, 2015-2018.

PATIENT(S)

A total of 14,961,207 pregnancies resulting in a singleton live birth.

INTERVENTION(S)

Any infertility treatment, including assisted reproductive technology and fertility-enhancing drugs.

MAIN OUTCOME MEASURE(S)

Neonatal (<28 days) mortality. The effect measure, risk ratio (RR), and 95% confidence interval (CI) were derived from log-linear Poisson models. A causal mediation analysis of the relationship between infertility treatment and mortality associated with preterm delivery (<37 weeks) was performed. The effects of exposure misclassification and unmeasured confounding biases were assessed.

RESULT(S)

Any infertility treatment was documented in 1.3% (n = 198,986) of pregnancies. Infertility treatment was associated with a 51% increased risk of neonatal mortality (RR 1.51, 95% CI 1.39-1.64), with a slightly higher risk for early neonatal mortality (RR 1.57, 95% CI 1.43-1.73) than late neonatal mortality (RR 1.33, 95% CI 1.11-1.58). These risks were similar for pregnancies conceived through assisted reproductive technology and fertility-enhancing drugs. The mediation analysis showed that 72% (95% CI 59-85) of the total effect of infertility treatment on neonatal mortality was mediated through preterm delivery. In a sensitivity analysis, following corrections for exposure misclassification and unmeasured confounding biases, these risks were higher for early, but not for late, neonatal mortality.

CONCLUSION(S)

Pregnancies conceived with infertility treatment are associated with increased neonatal mortality, and this association is largely mediated through preterm delivery. However, given the substantial underreporting of infertility treatment, these associations must be cautiously interpreted.

The association of adverse outcomes with pregnancy conception methods among low-risk term pregnancies

OBJECTIVE

To compare composite neonatal and maternal adverse outcomes among low-risk singleton pregnancies at 37-41 weeks among conception methods: spontaneously-conceived (SC) pregnancy; infertility medications and/or intrauterine insemination (IFM/IUI); and assisted reproductive technology (ART).

DESIGN

Population-based retrospective cohort study.

SETTING

US Vital Statistics datasets 2013-2017.

PATIENT(S)

Low-risk pregnancies (without hypertensive disorders, pregestational or gestational diabetes, or history of preterm birth) of women ≥20 years with nonanomalous singletons, who labored, delivered at 37-41 weeks, and had data on pregnancy conception method.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

The primary outcome was the composite neonatal adverse outcome (CNAO). The secondary outcome was the composite maternal adverse outcome (CMAO).

RESULT(S)

Of the 19.7 million deliveries during the study period, 54.0% (N = 10,676,184) met the inclusion criteria, with 99.0% (N = 10,573,741) being conceived spontaneously, 0.4% (N = 47,227) by IFM/IUI, and 0.5% (N = 55,216) by ART. The overall rate of CNAO was 6.68 per 1,000 live births. Compared with SC, the risk of CNAO was significantly higher among IFM/IUI (adjusted relative risk [aRR], 1.29; 95% CI, 1.18-1.41) and ART (aRR, 1.29; 95% CI, 1.18-1.39). The overall rate of CMAO was 2.50 per 1,000 live births. Compared with SC, the risk of CMAO was significantly increased among IFM/IUI (aRR, 1.72; 95% CI, 1.50-1.97) and ART (aRR, 2.40; 95% CI, 2.17-2.65).

CONCLUSION(S)

Among low-risk term singleton pregnancies, IFM/IUI and ART have modestly higher rates of adverse outcomes to maternal-neonatal dyad than SC.

The risk of birth defects with conception by ART

STUDY QUESTION

What is the association between ART conception and treatment parameters and the risk of birth defects?

SUMMARY ANSWER

Compared to naturally conceived singleton infants, the risk of a major nonchromosomal defect among ART singletons conceived with autologous oocytes and fresh embryos without use of ICSI was increased by 18%, with increases of 42% and 30% for use of ICSI with and without male factor diagnosis, respectively.

WHAT IS KNOWN ALREADY

Prior studies have indicated that infertility and ART are associated with an increased risk of birth defects but have been limited by small sample size and inadequate statistical power, failure to differentiate results by plurality, differences in birth defect definitions and methods of ascertainment, lack of information on ART treatment parameters or study periods spanning decades resulting in a substantial historical bias as ART techniques have improved.

STUDY DESIGN, SIZE, DURATION

This was a population-based cohort study linking ART cycles reported to the Society for Assisted Reproductive Technology Clinic Outcome Reporting System (SART CORS) from 1 January 2004 to 31 December 2015 that resulted in live births from 1 September 2004 to 31 December 2016 in Massachusetts and North Carolina and from 1 September 2004 to 31 December 2015 for Texas and New York: these were large and ethnically diverse States, with birth defect registries utilizing the same case definitions and data collected, and with high numbers of ART births annually. A 10:1 sample of non-ART births were chosen within the same time period as the ART birth. Naturally conceived ART siblings were identified through the mother's information. Non-ART children were classified as being born to women who conceived with ovulation induction (OI)/IUI when there was an indication of infertility treatment on the birth certificate, but the woman did not link to the SART CORS; all others were classified as being naturally conceived.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The study population included 135 051 ART children (78 362 singletons and 56 689 twins), 23 647 naturally conceived ART siblings (22 301 singletons and 1346 twins) and 9396 children born to women treated with OI/IUI (6597 singletons and 2799 twins) and 1 067 922 naturally conceived children (1 037 757 singletons and 30 165 twins). All study children were linked to their respective State birth defect registries to identify major defects diagnosed within the first year of life. We classified children with major defects as either chromosomal (i.e. presence of a chromosomal defect with or without any other major defect) or nonchromosomal (i.e. presence of a major defect but having no chromosomal defect), or all major defects (chromosomal and nonchromosomal). Logistic regression models were used to generate adjusted odds ratios (AORs) and 95% CI to evaluate the risk of birth defects due to conception with ART (using autologous oocytes and fresh embryos), and with and without the use of ICSI in the absence or presence of male factor infertility, with naturally conceived children as the reference. Analyses within the ART group were stratified by combinations of oocyte source (autologous, donor) and embryo state (fresh, thawed), with births from autologous oocytes and fresh embryos as the reference. Analyses limited to fresh embryos were stratified by oocyte source (autologous, donor) and the use of ICSI. Triplets and higher-order multiples were excluded.

MAIN RESULTS AND THE ROLE OF CHANCE

A total of 21 998 singleton children (1.9%) and 3037 twin children (3.3%) had a major birth defect. Compared to naturally conceived children, ART singletons (conceived from autologous oocytes, fresh embryos without the use of ICSI) had increased risks of a major nonchromosomal birth defect (AOR 1.18, 95% 1.05, 1.32), cardiovascular defects (AOR 1.20, 95% CI 1.03, 1.40), and any birth defect (AOR 1.18, 95% CI 1.09, 1.27). Compared to naturally conceived children, ART singletons conceived (from autologous oocytes, fresh embryos) with the use of ICSI, the risks were increased for a major nonchromosomal birth defect (AOR 1.30, 95% CI 1.16, 1.45 without male factor diagnosis; AOR 1.42, 95% CI 1.28, 1.57 with male factor diagnosis); blastogenesis defects (AOR 1.49, 95% CI 1.08, 2.05 without male factor; AOR 1.56, 95% CI 1.17, 2.08 with male factor); cardiovascular defects (AOR 1.28, 95% CI 1.10,1.48 without male factor; AOR 1.45, 95% CI 1.27, 1.66 with male factor); in addition, the risk for musculoskeletal defects was increased (AOR 1.34, 95% CI 1.01, 1.78 without male factor) and the risk for genitourinary defects in male infants was increased (AOR 1.33, 95% CI 1.08, 1.65 with male factor). Comparisons within ART singleton births conceived from autologous oocytes and fresh embryos indicated that the use of ICSI was associated with increased risks of a major nonchromosomal birth defect (AOR 1.18, 95% CI 1.03, 1.35), blastogenesis defects (AOR 1.65, 95% CI 1.08, 2.51), gastrointestinal defects (AOR 2.21, 95% CI 1.28, 3.82) and any defect (AOR 1.11, 95% CI 1.01, 1.22). Compared to naturally conceived children, ART singleton siblings had increased risks of musculoskeletal defects (AOR 1.32, 95% CI 1.04, 1.67) and any defect (AOR 1.15, 95% CI 1.08, 1.23). ART twins (conceived with autologous oocytes, fresh embryos, without ICSI) were at increased risk of chromosomal defects (AOR 1.89, 95% CI 1.10, 3.24) and ART twin siblings were at increased risk of any defect (AOR 1.26, 95% CI 1.01, 1.57). The 18% increased risk of a major nonchromosomal birth defect in singleton infants conceived with ART without ICSI (∼36% of ART births), the 30% increased risk with ICSI without male factor (∼33% of ART births), and the 42% increased risk with ICSI and male factor (∼31% of ART births) translates into an estimated excess of 386 major birth defects among the 68 908 singleton children born by ART in 2017.

LIMITATIONS, REASONS FOR CAUTION

In the SART CORS database, it was not possible to differentiate method of embryo freezing (slow freezing vs vitrification), and data on ICSI was only available in the fresh embryo ART group. In the OI/IUI group, it was not possible to differentiate type of non-ART treatment utilized, and in both the ART and OI/IUI groups, data were unavailable on duration of infertility.

WIDER IMPLICATIONS OF THE FINDINGS

The use of ART is associated with increased risks of a major nonchromosomal birth defect, cardiovascular defect and any defect in singleton children, and chromosomal defects in twins; the use of ICSI further increases this risk, the most with male factor infertility. These findings support the judicious use of ICSI only when medically indicated. The relative contribution of ART treatment parameters versus the biology of the subfertile couple to this increased risk remains unclear and warrants further study.

STUDY FUNDING/COMPETING INTEREST(S)

This project was supported by grant R01 HD084377 from the National Institute of Child Health and Human Development. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institute of Child Health and Human Development, or the National Institutes of Health, nor any of the State Departments of Health which contributed data. E.W. is a contract vendor for SART; all other authors report no conflicts.

TRIAL REGISTRATION NUMBER

N/A.

Increased risk of severe maternal morbidity among infertile women: analysis of US claims data

BACKGROUND

Severe maternal morbidity continues to be an issue of national and global concern and is increasing in incidence. The incidence of infertility is also on the rise, and infertile women experience a higher risk of incident chronic medical disease and cancer, suggesting that fertility may serve as a window to a woman's overall health.

OBJECTIVE

To investigate the risk of severe maternal morbidity by maternal fertility status.

MATERIALS AND METHODS

This was a retrospective cohort analysis using Optum's de-identifed Clinformatics Data Mart Database between 2003 and 2015. Infertile women stratified by infertility diagnosis, testing, or treatment were compared to fertile women seeking routine gynecologic care. In both groups, only women who underwent pregnancy and delivery of a singleton during the follow-up period were included. Main outcomes were severe maternal morbidity indicators, defined by the Centers for Disease Control and Prevention and identified by International Classification of Diseases 10^th Revision and Common Procedural Technology codes within 6 weeks of each delivery. Results were adjusted for maternal age, race, education, nulliparity, smoking, obesity, delivery mode, preterm birth, number of prenatal visits, and year of delivery.

RESULTS

A total of 19,658 women comprised the infertile group and 525,695 women comprised the fertile group. The overall incidence of any severe maternal morbidity indicator was 7.0% among women receiving fertility treatment, 6.4% among women receiving a fertility diagnosis, 5.5% among women receiving fertility testing, and 4.3% among fertile women. Overall, infertile women had a significantly higher risk of developing any severe maternal morbidity indicator (adjusted odds ratio, 1.22; confidence interval, 1.14-1.31, P < .01) as well as a significantly higher risk of disseminated intravascular coagulation (adjusted odds ratio, 1.48; confidence interval, 1.26-1.73, P < .01), eclampsia (adjusted odds ratio, 1.37; confidence interval, 1.05-1.79, P < .01), heart failure during procedure or surgery (adjusted odds ratio, 1.54; confidence interval, 1.21-1.97, P < .01), internal injuries of the thorax, abdomen, or pelvis (adjusted odds ratio, 1.59; confidence interval, 1.12-2.26, P < .01), intracranial injuries (adjusted odds ratio, 1.77; confidence interval, 1.20-2.61, P < .01), pulmonary edema (adjusted odds ratio, 2.18; confidence interval, 1.54-3.10, P < .01), thrombotic embolism (adjusted odds ratio, 1.58; confidence interval, 1.14-2.17, P < .01), and blood transfusion (adjusted odds ratio, 1.50; confidence interval, 1.30-1.72, P < .01) compared to fertile women. Fertile women did not face a significantly higher risk of any maternal morbidity indicator compared to infertile women. In subgroup analysis by maternal race/ethnicity, the likelihood of severe morbidity was significantly higher among fertile black women compared to fertile white women. There was no difference between infertile black women and infertile white women after multivariable adjustment.

CONCLUSION

Using an insurance claims database, we report that women diagnosed with infertility and women receiving fertility treatment experience a significantly higher risk of multiple indicators of severe maternal morbidity compared to fertile women. The increased risk of severe maternal morbidity noted among fertile black women compared to fertile white women is attenuated among infertile black women, who face risks similar to those of infertile white women.

Negotiating risk and choice in multifetal pregnancies

Today, across all aspects of societal living, risk assessment is an ever-present exercise. Pervasiveness of technology in the everyday life has caused the world of 'risk' to change tremendously, and this is particularly true for childbearing females. The social construction of pregnancy and childbirth as, arguably, medical events that necessitate medical intervention - ever more so for multifetal pregnancies - makes it almost impossible to avoid the notions of risk that surround the events. Drawing on semi-structured interviews with 41 mothers of twins or triplets, we investigate how understandings of risk, combined with the ideology of good motherhood and information provided by physicians impact perceptions of fetal reduction or termination. We have discussed and theorized empirical findings within the framework of risk, discourses of the responsibilization of females, and the potential 'sacred child' in a context where selective reduction becomes a potentiality.

Gestational Weight Gain and Adverse Birth Outcomes in Twin Pregnancies

OBJECTIVE

To evaluate the association between gestational weight gain in twin pregnancies and small-for-gestational-age (SGA) and large-for-gestational-age (LGA) birth, preterm birth before 32 weeks of gestation, cesarean delivery, and infant death within each prepregnancy body mass index (BMI) category.

METHODS

Data in this population-based study came from Pennsylvania-linked infant birth and death records (2003-2013). We studied 54,836 twins born alive before 39 weeks of gestation. Total pregnancy weight gain (kg) was converted to gestational age-standardized z scores. Multivariable modified Poisson regression models stratified by prepregnancy BMI were used to estimate associations between z scores and outcomes. A probabilistic bias analysis, informed by an internal validation study, evaluated the effect of BMI and weight gain misclassification.

RESULTS

Gestational weight gain z score was negatively associated with SGA and positively associated with LGA and cesarean delivery in all BMI groups. The relation between weight gain and preterm birth was U-shaped in nonobese women. An increased risk of infant death was observed for very low weight gain among normal-weight women and for high weight gain among women without obesity. Most excess risks of these outcomes were observed at weight gains at 37 weeks of gestation that are equivalent to less than 14 kg or more than 27 kg in underweight or normal-weight women, less than 11 kg or more than 28 kg in overweight women, and less than 6.4 kg or more than 26 kg in women with obesity. The bias analysis supported the validity of the conventional analysis.

CONCLUSION

Very low or very high weight gains were associated with the adverse outcomes we studied. If the associations we observed are even partially reflective of causality, targeted modification of pregnancy weight gain in women carrying twins might improve pregnancy outcomes.

A systematic review of database validation studies among fertility populations

STUDY QUESTION

Are routinely collected data from fertility populations adequately validated?

SUMMARY ANSWER

Of the 19 studies included, only one validated a national fertility registry and none reported their results in accordance with recommended reporting guidelines for validation studies.

WHAT IS KNOWN ALREADY

Routinely collected data, including administrative databases and registries, are excellent sources of data, particularly for reporting, quality assurance, and research. However, these data are subject to misclassification bias due to misdiagnosis or errors in data entry and therefore need to be validated prior to using for clinical or research purposes.

STUDY DESIGN SIZE DURATION

We conducted a systematic review by searching Medline, Embase, and CINAHL from inception to 6 October 2016 to identify validation studies of databases that contain routinely collected data in an ART setting. Webpages of international ART centers were also searched.

PARTICIPANTS/MATERIALS SETTING METHODS

We included studies that compared at least two data sources to validate ART population data. Key words and MeSH terms were adapted from previous systematic reviews investigating routinely collected data (e.g. administrative databases and registries), measures of validity (including sensitivity, specificity, and predictive value), and ART (including infertility, IVF, advanced reproductive age, and diminished ovarian reserve). Only full-text studies in English were considered. Results were synthesized qualitatively. The electronic search yielded 1074 citations, of which 19 met the inclusion criteria.

MAIN RESULTS AND THE ROLE OF CHANCE

Two studies validated a fertility database using medical records; seven studies used an IVF registry to validate vital records or maternal questionnaires, and two studies failed to adequately describe their reference standard. Four studies investigated the validity of mode of conception from birth registries; two studies validated diagnoses or treatments in a fertility database; four studies validated a linkage algorithm between a fertility registry and another administrative database; one study created an algorithm in a single database to identify a patient population. Sensitivity was the most commonly reported measure of validity (12 studies), followed by specificity (9 studies). Only three studies reported four or more measures of validation, and five studies presented CIs for their estimates. The prevalence of the variable in the target population (pre-test prevalence) was reported in seven studies; however, only four of the studies had prevalence estimates from the study population (post-test prevalence) within a 2% range of the pre-test estimate. The post-test estimate was largely discrepant from the pre-test value in two studies.

LIMITATIONS REASONS FOR CAUTION

The search strategy was limited to the studies and reports published in English, which may not capture validation studies from countries that do not speak English. Furthermore, only three specific fertility-based diagnostic variables (advanced reproductive age, diminished ovarian reserve, and chorionicity) were searched in Medline, Embase, and CINAHL. Consequently, published studies with other diagnoses or conditions relevant to infertility may not have been captured in our review.

WIDER IMPLICATIONS OF THE FINDINGS

There is a paucity of literature on validation of routinely collected data from a fertility population. Furthermore, the prevalence of the markers that have been validated are not being presented, which can lead to biased estimates. Stakeholders rely on these data for monitoring outcomes of treatments and adverse events; therefore, it is essential to ascertain the accuracy of these databases and make the reports publicly available.

STUDY FUNDING/COMPETING INTERESTS

This study was supported by Canadian Institutes of Health Research (CIHR) (FDN-148438). There are no competing interests for any of the authors.

REGISTRATION NUMBER

International Prospective Register of Systematic Reviews ID: CRD42016048466.

Risk of severe maternal morbidity by maternal fertility status: a US study in 8 states

BACKGROUND

Over the past 2 decades the characteristics of women giving birth in the United States and the nature of the births themselves have changed dramatically, with increases in older maternal age, plural births, cesarean deliveries, and conception from infertility treatment.

OBJECTIVE

We sought to evaluate the risk of severe maternal morbidity by maternal fertility status, and for in vitro fertilization pregnancies, by oocyte source and embryo state combinations.

STUDY DESIGN

Women in 8 states who underwent in vitro fertilization cycles resulting in a live birth during 2004 through 2013 were linked to their infant's birth certificates; a 10:1 sample of births from non-in vitro fertilization deliveries were selected for comparison; those with an indication of infertility treatment on the birth certificate were categorized as subfertile, all others were categorized as fertile. In vitro fertilization pregnancies were additionally categorized by oocyte source (autologous vs donor) and embryo state (fresh vs thawed). Maternal morbidity was identified from the birth certificate, modeled using logistic regression, and reported as adjusted odds ratios [95% confidence intervals]. The reference group was fertile women.

RESULTS

The study population included 1,477,522 pregnancies (1,346,118 fertile, 11,298 subfertile, 80,254 in vitro fertilization autologous-fresh, 21,964 in vitro fertilization autologous-thawed, 13,218 in vitro fertilization donor-fresh, and 4670 in vitro fertilization donor-thawed pregnancies): 1,420,529 singleton, 54,573 twin, and 2420 triplet+ pregnancies. Compared to fertile women, subfertile and the 4 groups of in vitro fertilization-treated women had increased risks for blood transfusion and third- or fourth-degree perineal laceration (subfertile, 1.58 [1.23-2.02] and 2.08 [1.79-2.43]; autologous-fresh, 1.33 [1.14-1.54] and 1.37 [1.26-1.49]; autologous-thawed, 1.94 [1.60-2.36] and 2.10 [1.84-2.40]; donor-fresh, 2.16 [1.69-2.75] and 2.11 [1.66-2.69]; and donor-thawed, 2.01 [1.38-2.92] and 1.28 [0.79-2.08]). Also compared to fertile women, the risk of unplanned hysterectomy was increased for in vitro fertilization-treated women in the autologous-thawed group (2.80 [1.96-4.00]), donor-fresh group (2.14 [1.33-3.44]), and the donor-thawed group (2.46 [1.33-4.54]). The risk of ruptured uterus was increased for in vitro fertilization-treated women in the autologous-fresh group (1.62 [1.14-2.29]). Among women with a prior birth, the risk of blood transfusion after a vaginal birth was increased for subfertile women (2.91 [1.38-6.15]), and women in all 4 in vitro fertilization groups (autologous-fresh, 1.93 [1.23-3.01]; autologous-thawed, 2.99 [1.78-5.02]; donor-fresh, 5.13 [2.39-11.02]; and donor-thawed, 5.20 [1.83-14.82]); the risk after a cesarean delivery was increased in the autologous-thawed group (1.74 [1.29-2.33]) and the donor-fresh group (1.62 [1.07-2.45]). Unplanned hysterectomy was increased in the autologous-thawed (2.31 [1.43-3.71]) and donor-thawed (2.45 [1.06-5.67]) groups.

CONCLUSION

The risks of severe maternal morbidity are increased for subfertile and in vitro fertilization births, particularly in pregnancies that are not from autologous, fresh cycles.

Risk of prematurity and infant morbidity and mortality by maternal fertility status and plurality

PURPOSE

To evaluate the risk of prematurity and infant mortality by maternal fertility status, and for in vitro fertilization (IVF) pregnancies, by oocyte source and embryo state combinations.

METHODS

Women in 14 States who had IVF-conceived live births during 2004-13 were linked to their infant's birth and death certificates; a 10:1 sample of non-IVF births was selected for comparison; those with an indication of infertility treatment on the birth certificate were categorized as subfertile, all others were categorized as fertile. Risks were modeled separately for the fertile/subfertile/IVF (autologous-fresh only) group and for the IVF group by oocyte source-embryo state combinations, using logistic regression, and reported as adjusted odds ratios (AORs) and 95% confidence intervals (CI).

RESULTS

The study population included 2,474,195 pregnancies. Placental complications (placenta previa, abruptio placenta, and other excessive bleeding) and prematurity were both increased with pregestational and gestational diabetes and hypertension, among subfertile and IVF groups, and in IVF pregnancies using donor oocytes. Both subfertile and IVF pregnancies were at risk for prematurity and NICU admission; IVF infants were also at risk for small-for-gestation birthweight, and subfertile infants had greater risks for neonatal and infant death. Within the IVF group, pregnancies with donor oocytes and/or thawed embryos were at greater risk of large-for-gestation birthweight, and pregnancies with thawed embryos were at greater risk of neonatal and infant death.

CONCLUSIONS

Prematurity was associated with placental complications, diabetes and hypertension, subfertility and IVF groups, and in IVF pregnancies, donor oocytes and/or thawed embryos.

Childbirth after adolescent and young adult cancer: a population-based study

PURPOSE

Annually, > 45,000 US women are diagnosed with cancer during adolescence and young adulthood (AYA). Since 2006, national guidelines have recommended fertility counseling for cancer patients. We examined childbirth after AYA cancer by calendar period, cancer diagnosis, and maternal characteristics.

METHODS

We identified a cohort of women with an incident invasive AYA cancer diagnosis at ages 15-39 during 2000-2013 in North Carolina. Cancer records were linked with statewide birth certificates through 2014. Hazard ratios (HR) and 95% confidence intervals (CI) for first post-diagnosis live birth were calculated using Cox proportional hazards regression.

RESULTS

Among 17,564 AYA cancer survivors, 1989 had ≥ 1 birth after diagnosis during 98,397 person-years. The 5- and 10-year cumulative incidence of live birth after cancer was 10 and 15%, respectively. AYA survivors with a post-diagnosis birth were younger at diagnosis, had lower stage disease, and had less often received chemotherapy than those without a birth. The 5-year cumulative incidence of post-diagnosis birth was 10.0% for women diagnosed during 2007-2012, compared to 9.4% during 2000-2005 (HR = 1.01; 0.91, 1.12), corresponding to periods before and after publication of American Society of Clinical Oncology fertility counseling guidelines in 2006.

CONCLUSIONS

Despite advances in fertility preservation options and recognition of fertility counseling as a part of high-quality cancer care, the incidence of post-diagnosis childbirth has remained stable over the last 15 years.

IMPLICATIONS FOR CANCER SURVIVORS

Our study uses statewide data to provide recent, population-based estimates of how often AYA women have biological children after a cancer diagnosis.

Influence of paternal age on perinatal outcomes

BACKGROUND

There is an increasing trend to delay childbearing to advanced parental age. Increased risks of advanced maternal age and assisted reproductive technologies are widely accepted. There are limited data regarding advanced paternal age. To adequately counsel patients on risk, more research regarding advanced paternal age is necessary.

OBJECTIVE

We sought to determine the influence of paternal age on perinatal outcomes, and to assess whether this influence differs between pregnancies achieved spontaneously and those achieved with assisted reproductive technology.

STUDY DESIGN

A population-based retrospective cohort study of all live births in Ohio from 2006 through 2012 was completed. Data were evaluated to determine if advanced paternal age is associated with an increased risk of adverse outcomes in pregnancies. The analysis was stratified by status of utilization of assisted reproductive technology. Generalized linear regression models assessed the association of paternal age on pregnancy complications in assisted reproductive technology and spontaneously conceived pregnancies, after adjusting for maternal age, race, multifetal gestation, and Medicaid status, using Stata software (Stata, Release 12; StataCorp, College Station, TX).

RESULTS

Paternal age was documented in 82.2% of 1,034,552 live births in Ohio during the 7-year study period. Paternal age ranged from 12-87 years, with a median of 30 (interquartile range, 26-35) years. Maternal age ranged from 11-62 years, with a median of 27 (interquartile range, 22-31) years. The use of assisted reproductive technology in live births increased as paternal age increased: 0.1% <30 years vs 2.5% >60 years, P < .001. After accounting for maternal age and other confounding risk factors, increased paternal age was not associated with a significant increase in the rate of preeclampsia, preterm birth, fetal growth restriction, congenital anomaly, genetic disorder, or neonatal intensive care unit admission. The influence of paternal age on pregnancy outcomes was similar in pregnancies achieved with and without assisted reproductive technology.

CONCLUSION

Older paternal age does not appear to pose an independent risk of adverse perinatal outcomes, in pregnancies achieved either with or without assisted reproductive technology. However, small effect sizes such as very small risk increases or decreases may not be detectable despite the large sample size in this study of >830,000 births.

Assisted Reproductive Technology and Birth Defects: Effects of Subfertility and Multiple Births

BACKGROUND

Assisted reproductive technology (ART) has been associated with birth defects, but the contributions of multiple births and underlying subfertility remain unclear. We evaluated the effects of subfertility and mediation by multiple births on associations between ART and nonchromosomal birth defects.

METHODS

We identified a retrospective cohort of Massachusetts live births and stillbirths from 2004 to 2010 among ART-exposed, ART-unexposed subfertile, and fertile mothers using linked information from fertility clinics, vital records, hospital discharges, and birth defects surveillance. Log-binomial regression was used to estimate prevalence ratios and 95% confidence intervals (CIs). Mediation analyses were performed to deconstruct the ART-birth defects association into the direct effect of ART, the indirect effect of multiple births, and the effect of ART-multiples interaction.

RESULTS

Of 17,829 ART-exposed births, 355 had a birth defect, compared with 162 of 9431 births to subfertile mothers and 6183 of 445,080 births to fertile mothers. The adjusted prevalence ratio was 1.5 (95% CI, 1.3-1.6) for ART and 1.3 (95% CI, 1.1-1.5) in subfertile compared with fertile deliveries. We observed elevated rates of several birth defects with ART, including tetralogy of Fallot and hypospadias. Subfertility and multiple births affect these associations, with multiple births explaining 36% of the relative effect of ART on nonchromosomal birth defects.

CONCLUSION

Although the risk of birth defects with ART is small, a substantial portion of the relative effect is mediated through multiple births, with subfertility contributing an important role. Future research is needed to determine the impact of newer techniques, such as single embryo transfer, on these risks. Birth Defects Research 109:1144-1153, 2017. © 2017 Wiley Periodicals, Inc.

Impact of fertility treatment on severe maternal morbidity

OBJECTIVE

To determine if fertility treatment is associated with increased risk of severe maternal morbidity (SMM) compared with spontaneous pregnancies.

DESIGN

Retrospective cohort study.

SETTING

Academic medical center.

PATIENT(S)

In 2012, 6,543 women delivered live births >20 weeks gestation at our center. Women were categorized based on mode of conception: in vitro fertilization (IVF), non-IVF fertility treatment (NIFT), or spontaneous pregnancies.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

The main outcome was presence of true SMM, such as eclampsia, respiratory failure, and peripartum hysterectomy. Deliveries were screened with the use of: 1) International Classification of Diseases 9 codes; 2) prolonged postpartum stay; 3) maternal intensive care unit admissions, and 4) blood transfusion. The charts of women meeting the screening criteria were reviewed to identify true SMM based on a previously validated method, recognizing that medical record review is the criterion standard.

RESULT(S)

Of the 6,543 deliveries, 246 (3.8%) were IVF conceptions and 109 (1.7%) NIFT conceptions. Sixty-nine cases of true SMM were identified (1.1%). In multivariate analyses, any fertility treatment (IVF + NIFT) was associated with increased risk of SMM compared with spontaneous conceptions. In a subset analysis of singletons only, the association between any fertility treatment (IVF + NIFT) and SMM was not statistically significant.

CONCLUSION(S)

Overall, fertility treatment increased risk for SMM events. Given the limited sample size, the negative finding with singleton gestations is inconclusive. Larger multicenter studies with accurate documentation of fertility treatment and SMM cases are needed to further clarify the risk associated with singletons.