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

Abstract

Background Births to subfertile women, with and without infertility treatment, have been reported to have lower birthweights and shorter gestations, even when limited to singletons. It is unknown whether these decrements are due to parental characteristics or aspects of infertility treatment. Objective To evaluate the effect of maternal fertility status on the risk of pregnancy, birth, and infant complications. Study Design All singleton live births of ≥22 weeks’ gestation and ≥350 grams birthweight to Massachusetts resident women in 2004–10 were linked to hospital discharge and vital records. Women were categorized by their fertility status as in vitro fertilization (IVF), subfertile, or fertile. Women whose births linked to IVF cycles from the Society for Assisted Reproductive Technology Clinic Outcomes Reporting System were classified as IVF. Women with indicators of subfertility but not treated with IVF were classified as subfertile. Women without indicators of subfertility or IVF treatment were classified as fertile. Risks of fifteen adverse outcomes (gestational diabetes, pregnancy hypertension, antenatal bleeding, placental complications (placenta abruptio and placenta previa), prenatal hospitalizations, primary cesarean, very low birthweight (<1,500g), low birthweight (<2,500g), small-for-gestation birthweight (Z-score ≤−1.28), large-for-gestation birthweight (Z-score ≥1.28), very preterm (<32 weeks), preterm (<37 weeks), birth defects, neonatal death (0–27 days), and infant death (0–364 days of life) were modeled by fertility status with the fertile group as reference, and the subfertile group as reference, using multivariate log binomial regression and reported as adjusted risk ratios (ARRs) and 95% confidence intervals. Results The study population included 459,623 women (441,420 fertile, 8,054 subfertile, and 10,149 IVF). Women in the subfertile and IVF groups were older than their fertile counterparts. Risks for six out of six pregnancy outcomes and six out of nine infant outcomes were increased for the subfertile group, and five out of six pregnancy outcomes and seven out of nine infant outcomes were increased for the IVF group. For four of the six pregnancy outcomes (uterine bleeding, placental complications, prenatal hospitalizations, and primary cesarean) and two of the infant outcomes (low birthweight and preterm) the risk was greater in the IVF group, with non-overlapping confidence intervals to the subfertile group, indicating a substantially higher risk among IVF-treated women. The highest risks for the IVF women were uterine bleeding (ARR 3.80, 95% CI 3.31, 4.36) and placental complications (ARR 2.81, 95% CI 2.57, 3.08), and for IVF infants, very preterm birth (ARR 2.13, 95% CI 1.80, 2.52) and very low birthweight (ARR 2.15, 95% CI 1.80, 2.56). With subfertile women as reference, risks for the IVF group were significantly increased for uterine bleeding, placental complications, prenatal hospitalizations, primary cesarean, low and very low birthweight, and preterm and very preterm bir...

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

“…Higher plurality, though, is associated with much greater risks of pregnancy, birth, and infant adverse health outcomes compared to singletons. Comparing the outcomes in this study to the analysis of 459,623 singleton births in the MOSART project during this same time period (2004–10) (38), show the manifold increased risks of twins compared to singletons. Born an average of 3 V weeks earlier and 950 grams lighter, twins were more than ten times as likely to be born very low birthweight, low birthweight, or early preterm, and eight times more likely to be born preterm.…”

“…We used similar methods to that described in the singleton analysis using this same study population (38). The study design and setting, data sources, variables, and statistical analysis are similar, except for the additional provisions made for categorizing and analyzing twin pregnancies and twin infant pairs.…”

“…This study seeks to overcome these limitations by linking the Society for Assisted Reproductive Technology Clinic Outcomes Reporting System (SART CORS) data to birth certificate and hospital utilization data, as well as accounting for fertility status. This analysis is part of a larger population-based study of IVF in Massachusetts (15, 22–38). In this analysis, we have increased the sample size, expanded the number of adverse outcomes, and further divided the twin group by like gender and unlike gender pairs from the original analysis, based on 2004–08 births, with four adverse outcomes (28).…”

Are singleton pregnancies after assisted reproduction technology (ART) associated with a higher risk of placental anomalies compared with non‐ART singleton pregnancies? A systematic review and meta‐analysis

“…Large observational studies identified that ART pregnancies are associated with a significant risk of complications as compared with pregnancies after spontaneous conception (SC). These complications include preterm delivery, low birthweight, intrauterine growth restriction, gestational diabetes, pre‐eclampsia, fetal loss and placental anomalies . Although initially it was believed that these complications were more prevalent after ART due to the high incidence of multiple pregnancies, a high risk of these complications was also demonstrated in ART singleton pregnancies …”

“…In the last 2 years there have been a substantial number of published studies that evaluate the association of placental anomalies with ART pregnancies . Considering the marked increase in published data, a systematic appraisal of the available evidence was considered essential in order to confidently evaluate this proposed higher risk of placental anomalies after ART.…”