Effect of elevated estradiol levels on the hCG administration day on IVF pregnancy and birth outcomes in the long GnRH-agonist protocol: analysis of 3393 cycles.

ABSTRACT

INTRODUCTION: This retrospective study aimed to evaluate the association between elevated serum estradiol (E 2) levels on the human chorionic gonadotrophin (hCG) administration day and in vitro fertilization (IVF) pregnancy and birth outcomes in the long GnRH-agonist protocol. METHODS: This study analyzed the data of 3393 infertile women who underwent initial fresh IVF. The patients were categorized into high and low E 2 groups based on their serum E 2 levels on the hCG day. Pregnancy and birth outcomes were compared. RESULTS: The implantation rate, clinical pregnancy rate, and live birth rate were all significantly higher in the high E 2 group than in the low E 2 group (p < 0.05). The good-quality embryo rate and abortion rate did not significantly differ between the two groups. There were no significant differences in the mode of delivery, gestational age, birth weight, and fetal gender between the two groups. Furthermore, there were no differences in the risk of preterm birth, low birth weight, and fetal malformation between the two groups in 860 single live births. Subgroup analysis of singleton pregnancies in the high E 2 (E 2 ≥ 3757 pg/mL) group revealed a significant increase in abortion rate in the age group of ≥37 years. CONCLUSIONS: Elevated serum E 2 levels associated with controlled ovarian stimulation did not increase the risks of preterm birth, low birth weight, and fetal malformation. High E 2 on the hCG day had no detrimental effect on the implantation rate, clinical pregnancy rate, and live birth rate.