Cabergoline influences ovarian stimulation in hyperprolactinaemic patients with polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is characterized by abnormal gonadotrophin secretion, in particular an elevated serum concentration of LH, depressed FSH, and an LH/FSH ratio of >or =2. Mild, transient hyperprolactinaemia is frequently associated with PCOS (30% of patients); furthermore, it can be observed during the late follicular and luteal phases of both natural and stimulated cycles. It is suggested that a reduction of the dopamine inhibitory effect might raise both prolactin (PRL) and LH.

We compared ovarian stimulation in two groups of hyperprolactinaemic (hyperPRL)-PCOS patients; one group was treated with cabergoline, reducing PRL plasma concentrations to the range normally observed during ovulation induction. In the untreated hyperPRL-PCOS group, we noted a reduced total number of ampoules of recombinant FSH (P < 0.04), fewer days to reach HCG administration (P < 0.04), and significantly higher peak oestrogen plasma concentrations (P < 0.03) compared with the treated group. By ultrasound examination the same group showed significantly higher ovarian volume and an increased total number of follicles of every size. In untreated hyperPRL-PCOS patients, four cycles out of 65 were cancelled due to mild ovarian hyperstimulation syndrome (OHSS) that occurred during ovulation induction. Only one cycle out of 42 in the patients treated with cabergoline was cancelled. No significant differences in pregnancy rate nor in multiple pregnancy were found.

Our data suggest a dopaminergic control of LH release and support the use of cabergoline in the management of such patients, in order to provide better clinical control of ovarian response and consequently a reduction of the risk of OHSS, with no decrease in pregnancy rate.