Gonadotrophin response to luteinizing hormone releasing factor (LRF) in puerperal women.

Abstract

Abstract. Synthetic luteinizing hormone releasing factor (LRF) was administered intravenously in a dose of 200 μg to twenty normal lactating puerperal women and serum follicle‐stimulating hormone (FSH) and luteinizing hormone (LH) response to LRF was measured by double antibody radio‐immunoassay. Synthetic LRF failed to stimulate FSH secretion in all the eight volunteers in the 1st postpartum week. About half of the six subjects in the 3rd postpartum week responsed to LRF with a rise of serum FSH and LH. All the six lactating women in the 5th postpartum week were responsive to LRF and there was a concomitant rise in serum FSH and LH. These results suggest that gonadotrophic activity of the anterior pituitary is suppressed by an unknown mechanism during the first few weeks of puerperium and gonado‐trophin reserve function recovers completely around the 5th postpartum week. Thus, it might be assumed that puerperal anovulation or amenorrhoea is due to hypo‐thalamic‐pituitary dysfunction during the first few postpartum weeks and due to hypothalamic disorders after the 5th postpartum week.