The effect of length of the follicular phase on pregnancy outcome following single embryo transfer (ET) in hypergonadotropic women.

Objective: To evaluate whether a short follicular phase adversely affects pregnancy rates following in vitro fertilization-embryo transfer in women with diminished egg reserve similarly to women with short follicular phases and normal egg reserve.

Methods: A retrospective review of women with day 3 serum FSH > 12 mIU/ml having only a single embryo transfer. Pregnancy rates were determined according to length of follicular phase, i.e., until day of egg retrieval.

Results: The ongoing/delivery pregnancy rates for women having oocyte retrievals on day 10 or earlier was 20.0% (20/63) compared to 16.1% (34/210) for those having retrievals on day 11 or later (p = NS).

Conclusions: Either length of the follicular phase is not an important factor for achieving a pregnancy in women with diminished egg reserve or the use of ethinyl estradiol in the follicular phase negates the adverse effect of the short follicular phase even if it fails to lengthen this phase to at least ten days.