Effect of ART treatments on maternal and neonatal outcomes in singleton live births: A large-scale retrospective cohort study

The increased risk of pregnancy complications in the ART population has been reported, but the source of these risks remains controversial. The study aims to evaluate the association between ART treatments and patient characteristics with maternal and neonatal outcomes. This was a retrospective analysis of 45,159 singleton pregnant women at a hospital between 2018 and 2021. The maternal and neonatal outcomes included pregnancy-induced hypertension (PIH), preeclampsia (PE), gestational diabetes mellitus (GDM), placental abruption (PA), placenta accreta spectrum (PAS), postpartum hemorrhage (PPH), cesarean section, iatrogenic and spontaneous preterm birth, small for gestational age (SGA), low birth weight (LBW), macrosomia, and birth defects. We assessed the outcomes among the fresh embryo transfer (ET), frozen embryo transfer (FET), and spontaneous conception (SC) groups. Potential risk factors were further analyzed in the ART population. FET was associated with higher risks for PIH (SC: AOR, 1.97(1.51–2.57); fresh ET: AOR, 1.68(1.03–2.72)), PE (SC: 2.28(1.86–2.80); fresh ET: AOR, 1.61(1.11–2.33)), PAS (SC: AOR, 3.89(3.39–4.46); fresh ET: AOR, 2.23(1.70–2.92)), PPH (SC: AOR, 3.46(2.76–4.34)); fresh ET: 2.09(1.39–3.14)), and macrosomia (SC: 1.53(1.25–1.86); fresh ET: AOR, 2.87(1.89–4.35). Fresh ET was associated with higher risks for PA (SC: AOR, 2.19(1.51–3.18); FET: AOR, 0.39(0.17–0.90)), SGA (SC: AOR, 1.56(1.06–2.31), FET: AOR, 0.42(0.19–0.91)), and LBW (SC: AOR, 2.24(1.82–2.77), FET: AOR, 0.63 (0.44–0.89)), and fresh ET is an independent risk factor for PA and SGA. Furthermore, the risk of GDM was associated with the biological characteristic of low-fertility patients. Embryo status (fresh or frozen) is a key factor affecting the maternal and neonatal outcomes in ART treatments, while biological characteristics of infertile patients also play a certain role. •The study analyzed risk factors affecting maternal and neonatal outcomes in ART.•The study found that embryo status is the key risk factor in the ART process.•The biological characteristics of infertile patients also play a certain role.•The study comprehensively analyzed the risk of maternal and neonatal outcomes.•This is a large-scale retrospective study conducted in China.