Hyperprolactinaemia and long-term lactational amenorrhoea

Clinical details of lactational and menstrual history post-partum have been correlated with measurements of serum prolactin, luteinizing hormone, follicle stimulating hormone, oestradiol and progesterone in Transkei women in order to gain further insight into the role of prolactin in the maintenance of post-partum lactational amenorrhoea. Of seventy-four breast-feeding mothers studied, sixty-six had elevated serum levels of prolactin. Forty-four women were amenorrhoeic with minimal or absent endocrine evidence of ovarian activity. Of the twenty-seven lactating women who reported menstruation, twelve had high levels of prolactin and no apparent ovarian activity, eleven had lower prolactin levels and increased oestradiol levels suggesting ovarian follicular development, while only four women had increased progesterone levels indicating definite luteal activity. Three lactating women were pregnant. The results support previous reports that lactational amenorrhoea is associated with hyperprolactinaemia and a possible sequence of endocrine events resulting in the return of post-partum fertility is proposed.