Gilberto da Costa Freitas

Pattern of prolactin secretion after administration of gonadotropin-releasing hormone agonist at the preovulatory phase of intrauterine insemination cycles

CONTEXT AND OBJECTIVE Administration of a gonadotropin-releasing hormone (GnRH) agonist at the preovulatory phase is an option for triggering ovulation in assisted reproductive technology cycles. The aim of this work was to investigate the pattern of prolactin secretion after the administration of a single dose of GnRH-agonist at the preovulatory phase. DESIGN AND SETTING Descriptive study at a tertiary referral center. PARTICIPANTS Fifteen normally ovulating patients undergoing ovarian stimulation for intrauterine insemination were studied. METHODS Ovarian stimulation was carried out using human menopausal gonadotropin (intramuscular 75 IU daily). When at least one follicle reached 17 mm (observed echographically), 0.5 mg of buserelin acetate was administered. Blood samples were taken to determine prolactin concentrations, at the time of agonist injection and 4, 8, 12, 24 and 48 hours later. RESULTS A statistically significant increase in serum levels of prolactin was observed 4, 8 and 12 hours after GnRH-agonist administration, with a peak at 8 hours. CONCLUSION The administration of a single dose of GnRH-agonist at the preovulatory phase in patients undergoing ovarian stimulation performed with human menopausal gonadotropin causes a significant increase in serum prolactin levels.