RESUMEN
RESEARCH QUESTION: Are outlier high values of first-measured human chorionic gonadotrophin (HCG) following embryo transfer related to pregnancy complications, specifically pre-eclampsia? DESIGN: This retrospective cohort study screened 3448 women aged 18-45 years who underwent IVF between 2014 and 2019 and evaluated 614 women who had an intrauterine pregnancy following single embryo transfer (SET), 423 of whom had a live birth. Pregnancy and birth outcome information was available for final analysis in 280 cases. The setting was a university-based IVF centre. HCG was measured at a standardized time after the embryo transfer and the values correlated with adverse pregnancy outcomes associated with poor placentation. RESULTS: Women with first-measured HCG in the highest quintile had a higher incidence of pre-eclampsia than those with lower HCG concentrations (odds ratio [OR] 4.08, 95% confidence interval [CI] 1.41-11.82) even after controlling for age, body mass index, parity and type of embryo transfer. Additionally controlling for embryo stage at embryo transfer did not change the results (OR 3.97, 95% CI 1.37-11.46). No differences were found in the incidence of fetal growth restriction. CONCLUSIONS: This is the first known report that links high first-measured HCG after SET to an adverse pregnancy outcome. If confirmed by future studies, initiation of preventive interventions at a very early stage of pregnancy merits further evaluation in this cohort of patients.