[Estrogen role in the luteal phase support in in vitro fertilization with embryo transfer cycles]

To evaluate the effectiveness of estradiol administration for luteal phase support and to describe the progesterone and estradiol behavior in vitro fertilization-embryo transfer luteal phase.

Patients undergoing in vitro fertilization-embryo transfer with controlled ovarian hyperstimulation and using gonadotropin releasing hormone agonist. They were divided at random into two groups: group 1 would receive progesterone alone, and group 2 would take estrogen and progesterone. Serum concentrations of estradiol and progesterone were measured on days 7 and 14 post-embryo transfer.

We examined 52 patients; 24 received progesterone alone and 28 took estrogen and progesterone. Significantly higher estradiol and progesterone concentrations on day 14 were found in pregnant women. It was not on day 7. A significant increment of estrogen was found in the estrogen and progesterone group. Progesterone did not increase significantly. Pregnancy rate was the same in both groups.

For patients undergoing in vitro fertilization-embryo transfer, the addition of estradiol to the progesterone support regimen does not have beneficial effects in terms of pregnancy rate. On day 7 neither progesterone nor estradiol are good predictors of pregnancy.