Prolactin response to thyrotropin-releasing hormone in normoprolactinemic patients with ovulatory dysfunction and its use for selection of candidates for bromocriptine therapy.

It has been suggested in the past that some normoprolactinemic patients with amenorrhea or infertility respond to treatment with bromocriptine. However, the beneficial effect of this therapy in normoprolactinemic women remains controversial. Some authors have suggested that the responders suffer with "reactive" hyperprolactinemia and that this may be detected with thyrotropin releasing hormone (TRH) stimulation. In this study, we performed TRH stimulation tests in 538 patients with ovulatory dysfunction. Only those patients showing a peak prolactin response after TRH which exceeded 40 ng/ml were treated with bromocriptine. A direct correlation between peak prolactin level after TRH and a favorable response to treatment was observed. Serum testosterone and DHEA-sulfate levels did not correlate with prolactin response to TRH. A majority of patients with prolactin hyperresponse to TRH did not show a hyperresponse of TSH to TRH. This study suggests that incidence of beneficial response to bromocriptine therapy in normoprolactinemic women with ovulatory dysfunction is significantly higher in subjects exhibiting excessive prolactin response to TRH stimulation.