β-hCG elevation rate in early IVF pregnancies and obstetrical complications

IVF pregnancies are associated with higher prevalence of placental complications such as hypertensive disorders of pregnancy and growth restriction. Abnormal β-hCG elevation is strongly associated with short-term adverse pregnancy outcomes such as miscarriage and ectopic pregnancies. However, the significance of slow β-hCG elevation rate on pregnancies that do continue to live birth is unknown. Single center retrospective cohort study between 2008-2019 including 818 fresh cycles resulting in a live singleton birth. The study was approved by the institutional ethics committee. The first blood β-hCG measurement was performed 15±1 days after oocyte pickup and the second 2.2±0.6 days later. The slope between the two measurements was calculated and adjusted per two days. Slow hCG elevation was defined as a slope value below the 10th percentile (< 1.766). Maternal and neonatal outcomes were compared between cycles with a slow elevation (n=82) and a “normal” elevation (n=736) in hCG values. Multivariate analysis was used to control for potential confounders. There were no differences between the groups in baseline maternal and IVF treatment characteristics (Table 1). Newborns from cycles with a slow β-hCG elevation weighed significantly less (2913±626 gr vs. 3081±549 gr, p< 0.01). There was no significant difference in the rate of small for gestational age newborns. Women with a slow β-hCG elevation had significantly more gestational hypertension (10% vs 4%, OR 3.50, 95% CI 1.50-8.11) and preeclampsia related disorders (11% vs 3%, OR 3.51, 95% CI 1.58-7.80). This association remained significant after correcting for potential confounders (including maternal age, gestational age at delivery and nulliparity), in a multivariate analysis. There was no difference in preterm labor rates as well as mode of delivery between the groups (Table 2). Early pregnancy (4th-5th week) β-hCG elevation rate might be a novel marker for identifying patients at risk for hypertensive obstetrical complications. Tighter prenatal care could potentially reduce adverse pregnancy outcome.View Large Image Figure ViewerDownload Hi-res image Download (PPT)