Abstract:

Objective To evaluate the influence of high estradiol (E2) mass concentrations on the day of human chorionic gonadotrophin (hCG) administration during in vitro fertilization (IVF) on pregnancy outcomes of fresh IVF cycles and subsequent frozen-thawed embryo transfer cycles. Methods The data of patients undergoing IVF/intracytoplasmic sperm injection (ICSI) with long protocol were collected, and patients were divided into two groups according to serum mass concentrations of E2 on the day of hCG administration. The serum mass concentration of E2 on the day of hCG administration was ≥5 000 pg/mL in group A (n=154), and that was <5 000 pg/mL in group B (n=294). Patients in group A were subdivided into group A1 (fresh embryo transfer group, n=78) and group A2 (frozen embryo transfer group, n=76). The characteristics of transfer cycles and pregnancy outcomes were compared among groups. Results There was no significant difference in the fertilization rates and cleavage rates between group A and group B (P>0.05). There was no significant difference in the pregnancy rates and embryo implantation rates between group A and group B (P>0.05). The incidence of moderate and severe ovarian hyperstimulation syndrome (OHSS) in group A was significantly higher than that in group B (4.55% vs 1.36%)(P<0.05). The pregnancy rate (48.68%) and embryo implantation rate (29.14%) in group A2 were significantly higher than those in group A1 and group B （P<0.05）. Conclusion High serum E2 mass concentrations on the day of hCG administration are related to ovarian hyperresponsiveness and increased risk of OHSS, while have no significant relationship with IVF outcomes. Patients with high serum E2 mass concentrations on the day of hCG administration treated with all-embryo cryopreservation may result in favorable pregnancy outcomes.

Key words: estradiol, in vitro fertilization, all-embryo cryopreservation, pregnancy