Day 4 Estradiol Levels Predict Pregnancy Success in Women Undergoing Controlled Ovarian Hyperstimulation for IVF

Objective: To evaluate the usefulness of serum estradiol levels obtained on the fourth day of gonadotropin stimulation in predicting the likelihood of pregnancy during controlled ovarian hyperstimulation (COH) using luteal phase leuprolide acetate (LA).

Design: A 4-year retrospective analysis of day 4 estradiol levels and subsequent clinical pregnancy and delivery rates.

Setting: A university hospital tertiary referral center.

Patient(s): Couples undergoing IVF treatment.

Main Outcome Measure(s): Primary outcome measures included clinical pregnancy and delivery rates. Secondary outcome measures included the number of oocytes retrieved and the number of embryos available for transfer per COH cycle.

Result(s): The clinical pregnancy and delivery rates for cycles with day 4 estradiol levels of >75 pg/mL were 42.3% (30/71) and 32.4% (23/71), respectively. These rates differed significantly from those for cycles with day 4 estradiol levels of ≤75 pg/mL, which were only 9.1% (4/44) and 6.8% (3/44), respectively. The number of oocytes retrieved and the number of embryos available for transfer for cycles with day 4 estradiol levels of >75 pg/mL also differed significantly from those for cycles with day 4 estradiol levels of ≤75 pg/mL (11.4 and 7.8 versus 6.8 and 4.3, respectively).

Conclusion(s): Estradiol levels obtained on the fourth day of gonadotropin therapy are highly predictive of successful ovulation induction and pregnancy outcome in cycles using luteal phase LA.