Breast-feeding and Post Partum Amenorrhoea in Central Africa: 2. Prolactin And Post Partum Amenorrhoea
Delvoye, P.; Robyn, C.
Journal of Tropical Pediatrics 26(5): 184-189
1980
ISSN/ISBN: 0142-6338 DOI: 10.1093/tropej/26.5.184Document Number: 525782
Serum prolactin (PRL) concn. were determined in 39 breast-feeding women at 1-24 months post partum, 13 of whom had returned to menstruation and 26 of whom were amenorrhoeic. In both groups, differences between av. PRL concn. in samples taken just before and 30 min after the onset of nursing were not significant. However, mean basal PRL concn. was significantly higher in amenorrhoeic women than in those who had returned to menstruation (977 vs. 614 mu U/ml), and mean PRL concn. at the end of nursing in menstruating women was lower than mean concn. before nursing in amenorrhoeic women (750 vs. 977 mu U/ml). Serum PRL remained high in Idjwi women (rural Kivu) during the 1st 15 months post partum (700-1000 mu U/ml) and then fell progressively to <400 mu U/ml by 18-21 months. Concn. were similar in Bukavu city in the 1st 6 months but were subsequently lower (P <0.05) than in rural areas. In a study of 97 urban women for whom number of daily breast feeds was 1-3 (13 women), 4-6 (52 women) or >6 (26 women), mean serum PRL concn. were, resp., 525, 712 and 879 mu U/ml (P < 0.01 for difference between 1st and 3rd groups); mean post-partum period was approx. the same for each group (5-7 months). Thus, not only the duration of lactation, but also the mode of nursing, constitute regulatory factors for hyperprolactinaemia and prolonged post-partum amenorrhoea.