Pituitary responses to LRH in the postpartum periods

Abstract

Pituitary responses to luteinizing-hormone-releasing-hormone (LRH) in the postpartum periods were studied. Following a subcutaneous injection of 100 mug of synthetic LRH to postpartum subjects, no statistically significant changes in the levels of LH and FSH could be demonstrated in five subjects on postpartum day 1 or 3 and the three subjects on postpartum day 8. A normal elevation of LH and FSH following LRH was demonstrated in one subject 36 days post partum. The findings are in agreement with previous studies demonstrating a persistence of pituitary suppression during the early postpartum period. No correlation could be drawn between the pituitary responses to LRH and the plasma levels of estradiol-17 beta and progesterone.

PIP: Changes in pituitary responsiveness to luteinizing hormone-releasing hormone (LRH) during the postpartum period were studied and these changes were correlated with plasma estradiol and progesterone levels. 5 subjects were studied, ranging in age from 17-28 years. None of the subjects was breastfeeding. A 100-mcg subcutaneous injection of LRH (synthetic) was administered on postpartum Days 1, 3, 8, and 36 and changes in follicle stimulating hormone (FSH), luteinizing hormone (LH), and sex hormones were measured from blood samples collected 30 minutes, and hourly thereafter, after injection of LRH. No statistically significant changes in levels of LH and FSH were found at postpartum Day 1 or 3 in all 5 subjects, and no significant changes in these 2 parameters were found on postpartum Day 8 in 3 of the 5 subjects. At 36 days postpartum, 1 subject showed abnormal elevation of LH and FSH after the injection of LRH. All of these findings (tables present statistical data) show, as previous studies have demonstrated, that pituitary suppression persists during early postpartum. When the pituitary responses to LRH were correlated with plasma levels of estradiol 17-beta and progesterone, no significant correlations emerged.