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

Objective

To determine an optimal serum E₂ level on the day of hCG administration in controlled ovarian hyperstimulation (COH) during IVF-ET without compromising pregnancy outcome.

Design

Retrospective study.

Setting

Large 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.

Key Words: IVF-ET, controlled ovarian hyperstimulation, serum E₂ levels, pregnancy outcome