Pregnancy complications and placental histology in in vitro fertilization pregnancies with initial low serum β-hCG levels

Objective: To assess perinatal outcomes and placental findings after in vitro fertilization (IVF) with an initial low serum b-human chorionic gonadotropin (hCG). Design: A retrospective cohort study. Setting: University-affiliated tertiary hospital. Intervention(s): Low serum beta-hCG after transfer, defined as the low 10th percentile for the cohort on day 16 embryo age (low b-hCG group), compared with an initial serum beta-hCG at or above the low 10th percentile (control group). Patient(s): Live singleton births after IVF between 2009 and 2017. Main Outcome Measure(s): Primary outcomes were placental findings, including anatomic, inflammatory, vascular malperfusion, and villous maturation lesions, as categorized according to the Amsterdam Placental Workshop Group Consensus. Secondary outcomes included obstetric and perinatal outcomes. Result(s): The low 10th percentile of beta-hCG results corresponded to 149 mUI/mL. There were 103 cases in the low beta-hCG group, and 928 in the control group. Maternal demographics were similar between the groups, whereas blastocyte transfer was more common in the control group. Deliveries in the low beta-hCG group were associated with an increased rate of preterm births, 15.5% vs. 8.1%, which maintained significance after adjustment for confounders. Placentas in the low beta-hCG group were notable for a high rate of velamentous cord insertion, 19.4% vs. 7.7%, single umbilical artery 3.8% vs. 0.6%, and histological maternal vasculopathy, 10.6% vs. 4.8%. Conclusion: Live births after IVF with an initial low beta-hCG level are associated with a twofold increase in preterm births and placental gross and histological changes. It may thus be considered to observe such cases in a high-risk pregnancy setting. (C) 2022 by American Society for Reproductive Medicine.

Automated summary

This retrospective cohort study aimed to assess perinatal outcomes and placental findings after IVF with low serum beta-hCG levels. The study found that IVF pregnancies with initial low beta-hCG levels were associated with a twofold increase in preterm births and significant placental gross and histological changes. Monitoring such cases in high-risk pregnancy settings is recommended.