Maternal Outcomes Of Pregnancies Following Assisted Reproductive Technology:A Retrospective Cohort Study Of 7989 Chinese Women

Objective:The study was to explore associations between assisted reproductive technology (ART) and maternal outcomes compared to spontaneously conceived births.Materials and methods:We conducted a retrospective cohort study of pregnancies conceived by IVF (N=2663) in 2006-2014 compared to naturally conceived pregnancies (N=5326) after matching or controlling for maternal age. Pregnancy complications and perinatal complications of enrolled subjects were investigated by review of their medical notes and telephone interview. Multivariate logistic regression analysis was employed to explore the incidence of a series of pregnancy complications and perinatal complications between ART pregnancy group and natural pregnancy group, and to find the potential key factors influencing the perinatal outcomes of ART pregnancy (significance of differences was accepted at P<0.05).Results:After adjustment of maternal age, gravidity, parity, materal education, previous cesarean delivery and body mass index (BMI), pregnancies conceived by ART were associated with a statistically significant increased incidence of gestational diabetes mellitus (GDM) (OR,1.64,95% CI 1.35-1.97), gestational hypertension (OR, 1.95,95% CI 1.56-2.43), preeclampsia (OR,1.52,95% CI 1.14-2.03), and intrahepatic cholestasis of pregnancy (ICP) (OR,2.93,95% CI 2.45-3.50), compared with controls. In singleton gestations, the incidence of GDM, gestational hypertension and ICP was still significantly higher than the controls. However, there was no statistical difference in multiple gestations between ART group and natural control group. We found that pregnancies conceived by ART are associated with a series of prenatal and perinatal complications, including placenta previa (OR,2.15,95% CI 1.73-2.67), placental abruption (OR,5.06,95% CI 2.83-9.05), preterm premature rupture of fetal membranes (OR,2.98,95% CI 2.43-3.64), abnormal insertion of umbilical cord (OR,1.36,95% CI 1.06-1.76), placental adherence (OR,2.35,95% CI 1.90-2.92) and postpartum haemorrhage (OR,2.42,95% CI 1.94-3.02) in all birth, as well as in singletons for most complications, apart from preeclampsia in single gestations. However, no statistically significant increased incidence of perinatal complications was observed in multiple gestations between ART group and corresponding control group. In the ART singleton gestations,124 women had a pregnancy undergoing gestational hypertension (7.5%), as compared with 128 women in the ART multiple gestations (12.7%), suggesting that ART multiples were associated with a 64%increase in gestational hypertension (95% CI 1.25-2.14). Similarly, ART multiple conception was associated with an increased risk of preeclampsia (OR 1.98; 95% CI 1.32-2.97), ICP (OR 3.53; 95% CI 2.75-4.52), pPROM (OR 4.18; 95% CI 3.17-5.50), and postpartum haemorrhage (OR 2.75; 95% CI 2.03-3.72), compared with ART singleton conception.Conclusion:We conclude that pregnancies conceived by ART are at increased risks for a number of pregnancy complications, and perinatal complications, which could be attributed partly to the relatively high multiple pregnancy rate after ART. Elective single embryo transfer should be promoted in China to reduce the obstetrical risks of ART pregnancy. However, singletons of ART pregnancy exhibited increased maternal and neonatal complications as well, suggesting that ART itself is also significantly related to pathologic pregnancy.