Objective: To investigate the predictive value of the decline in serum estradiol on the second day after oocyte retrieval on the outcomes of in vitro fertilization (IVF) or intra-cytoplasmic sperm injection and embryo transfer (ICSI-ET) among high ovarian responders.
Design: Retrospective single-center cohort study.
Setting: Tertiary-care, university-affiliated teaching hospital. Patients Women aged 20-45 years undergoing assisted reproduction treatment from June 2014 to December 2015.
Interventions: A total of 980 cycles were included; 395 high responders (Group 1) and 256 normal responders (Group 3) underwent embryo transfer (ET) in fresh ET cycles. A total of 329 high ovarian responders who underwent cryopreservation of all embryos (Group 2) were recruited as controls. The cases were divided into the following five subgroups according to the rate of serum estradiol decline on the second day after oocyte retrieval: 50.00-59.99% (Subgroup A), 60.00-69.99% (Subgroup B), 70.00-79.99% (Subgroup C), 80.00-89.99% (Subgroup D) and ≥ 90.00% (Subgroup E). The clinical outcomes were analyzed.
Main outcome measures: Clinical pregnancy rate, implantation rate.
Results: In Group 1, the pregnancy rate decreased from 51.33 to 36.72% and the implantation rate decreased from 30.93 to 21.70% when the level of serum estradiol on the second day after oocyte retrieval decreased by more than 80%, which was a statistically significant decline (p < 0.05). The peak estradiol (E2) value and implantation rate were also significantly different (p < 0.05). In Group 2, the decline of serum E2 on the second day after oocyte retrieval had no significant effect on the clinical pregnancy rate or the implantation rate. The trend was similar in Group 3.
Conclusions: A decline in the E2 level of > 80% after oocyte retrieval may play an important role in unsatisfactory IVF/ICSI-ET outcomes among high ovarian responders.
Keywords: Clinical pregnancy rate; early luteal phase; estradiol; high ovarian response; implantation rate; in vitro fertilization.