Does anovulation induced by oral contraceptives favor pregnancy during the following two menstrual cycles?

OBJECTIVE

To compare IVF and pregnancy outcomes before and after anovulation induced by oral contraceptives.

DESIGN

Observational clinical study.

SETTING

Infertility clinic.

PATIENT(S): Forty women with two intact ovaries (32 of 40 couples with male factor infertility and 8 with unknown causes of infertility) underwent 190 IVF treatment cycles (55 natural cycles and 135 clomiphene citrate-stimulated cycles).

INTERVENTION(S): If the women failed to conceive after 2-4 IVF treatment cycles, oral contraceptives were used to induce anovulation for 1 month before IVF was performed in two consecutive cycles.

MAIN OUTCOME MEASURE(S): Rates of oocyte retrieval, fertilization, cleavage, preembryo formation, pregnancy, and implantation were compared before and after a period of anovulation.

RESULT(S): The pregnancy rate per cycle of the first and second cycle combined (23%) and that of the second cycle alone (30%) after a period of anovulation were significantly higher than that observed before a period of anovulation (9%).

CONCLUSION(S): Anovulation induced by oral contraceptives, showing bilateral ovarian quiescence, enhances pregnancy rates in the following two menstrual cycles of IVF treatment.