Abstract

PIP: On the theory that early pregnancy may protect women against breast cancer by a long-term depression of prolactin secretion, basal and perphenazine-stimulated release of prolactin, as well as basal and GnRH- stimulated release of LH and FSH were assayed in women before and after their 1st full term pregnancy, and in groups of parous and nulliparous women. The study groups were 15 women aged 18-23 and 9 women aged 29- 40. All hormone samples were taken at 0800 in the early follicular phase on women who had never taken oral contraceptives, or in the cross section survey, women who had not been exposed for at least 6 months V体育安卓版. There were no significant differences in LH or FSH basal or stimulated levels for 100 minutes after GnRH. In contrast after term pregnancy both basal and stimulated prolactin levels were significantly lower than comparable levels in nulliparous controls. Parous women returned for their second prolactin assay from 5-11 months after delivery. The cross-section basal prolactin levels were done from 12-150 months after delivery, with no evidence of an effect of age, parity or elapsed time. These results are appropriate for a protective factor against breast cancer, and prolactin is known to stimulate breast neoplasm in rodents. .