Does transient hyperprolactinemia during ovarian hyperstimulation interfere with conception or pregnancy outcome?

The significance of transiently increased serum prolactin (PRL) levels on pregnancy rates in in vitro fertilization (IVF) is unknown. The aim of this study was to evaluate PRL levels in IVF patients who conceived and in matched controls who did not. Thirty-seven IVF cycles resulting in pregnancy and 74 nonpregnant cycles were compared. Prolactin was measured before ovarian stimulation with clomiphene citrate, and human menopausal gonadotropin and estradiol (E2) and PRL were measured 8 hours after human chorionic gonadotropin (hCG) administration at midcycle. Before ovarian stimulation, serum PRL levels were not different in the pregnant and nonpregnant women (11.1 +/- 0.6 [mean +/- standard error] micrograms/l and 10.1 +/- 0.4 micrograms/l, respectively). After hCG, PRL levels were significantly higher in the pregnant women than in the nonpregnant women (20.8 +/- 1.6 and 16.0 +/- 0.9 micrograms/l, respectively; P less than 0.005) and more pregnant than nonpregnant women had elevated PRL levels (49% versus 28%, respectively; P less than 0.05). There was no correlation between PRL and E2 in either group. The abortion rate was not different between the women with elevated PRL (22.2%) and the normoprolactinemic women (31.6%). These results do not support treatment of transient hyperprolactinemia with dopamine agonists in IVF patients.