Serum estradiol levels during controlled ovarian hyperstimulation influence the pregnancy outcome of in vitro fertilization in a concentration-dependent manner

ObjectiveTo determine an optimal serum E2 level on the day of hCG administration in controlled ovarian hyperstimulation (COH) during IVF-ET without compromising pregnancy outcome.DesignRetrospective study.SettingLarge urban medical center.Patient(s)Data of 455 cycles of fresh IVF-ET with COH.Intervention(s)Serum E2 levels on the day of hCG administration were categorized into five groups: group A (<1000 pg/mL), group B (1000–2000 pg/mL), group C (2000–3000 pg/mL), group D (3000–4000 pg/mL), and group E (>4000 pg/mL).Main Outcome Measure(s)Serum E2 levels, number of oocytes retrieved, pregnancy outcomes.Result(s)Of 455 cycles, 148 (32.5%) cycles resulted in clinical pregnancy. The implantation rate was 12.2%, and the delivery rate was 18.7%. The number of oocytes obtained increased with increasing serum E2 levels. The pregnancy rate gradually increased from group A to D as E2 levels increased but decreased in group E. In women <38 years, the IVF-ET outcomes were similar to those of total patients. However, in women ≥38 years old, pregnancy and delivery rates were higher in group C than in other groups.Conclusion(s)These results show that serum E2 levels have a concentration-dependent effect on the pregnancy outcome, suggesting an optimal range of E2 level for achieving a successful pregnancy. This optimal range of serum E2 level in women is age dependent: 3000–4000 pg/mL for women <38 years and 2000–3000 pg/mL for women ≥38 years.