TSH and prolactin responses to TRH in patients with premenstrual syndrome.

The thyroid-stimulating hormone (TSH) and prolactin responses to thyrotropin-releasing hormone (TRH), administered during the follicular and luteal phases of the menstrual cycle, were examined in 14 women with prospectively confirmed premenstrual syndrome and in nine control subjects. There were no differences in basal or maximum increase in TSH or prolactin values between menstrual cycle phases in patients or in control subjects or between patients and control subjects in either phase. However, there was significantly greater variability in TSH response to TRH among symptomatic patients (seven of 10 patients: three with blunted and four with augmented response) than among control subjects (none of nine patients).