Estradiol-to-follicle Ratio on Human Chorionic Gonadotropin Day is a Novel Predictor of Gestational Diabetes Mellitus in Women Receiving Fresh Embryo Transfer

AimsTo assess the predictive value of estradiol (E2) related parameters on the incidence of gestational diabetes mellitus (GDM) in women undergoing fresh embryo transfer.Materials and methodsA Post-hoc analysis of a prospective cohort study.ResultsWe identified an optimal E2/follicle (E2/F) ratio threshold of 246.03 pg/ml on the day of human chorionic gonadotropin (hCG) administration. Women with an E2/F ratio exceeding this threshold had significantly lower rates of GDM (12.75% vs. 20.41%, P < 0.001) and ovarian hyperstimulation syndrome (OHSS) (11.75% vs. 15.48%, P = 0.03). Additional E2 parameters were also evaluated: baseline E2, E2 on hCG day, E2 increase, and E2 fold change. Lower GDM rates were observed in women with baseline E2 above 31.50 pg/ml (13.51% vs. 19.42%, P <0.01), E2 on hCG day above 3794.50 pg/ml (12.26% vs. 19.32%, P < 0.001), and E2 increase above 3771.50 pg/ml (12.24% vs. 19.28%, P < 0.001). There were no significant differences in OHSS rates for these additional E2 parameters. After adjusting for confounders, lower E2/F ratio (OR: 1.626, 95% CI: 1.229-2.150, P <0.01), E2 on hCG day (OR: 1.511, 95% CI: 1.133-2.016, P = 0.01), and E2 increase (OR: 1.522, 95% CI: 1.141-2.031, P <0.01) were identified as risk factors for GDM.ConclusionThis study demonstrates that an E2/F ratio over 246.03 pg/ml is significantly associated with a reduced risk of both GDM and OHSS in women undergoing fresh embryo transfer, highlighting the E2/F ratio as a superior predictive biomarker compared to other E2-related parameters.