Serum prolactin and progesterone concentrations in ovulatory infertility

The luteal phase serum prolactin and progesterone concentrations were studied by radioimmunoassay in 31 ovulatory but infertile women and 58 women wearing intrauterine device (IUD). In the infertile patients the prolactin concentrations were significantly higher (mean +/- SE 24.0 +/- 1.0 mug/l vs. 18.7 +/- mug/l) than in IUD users (p less than 0.001), and the progesterone concentrations were lower (22.9 +/- 1.7 vs. 37.4 +/- 2.3 mnol/l) (p less than 0.001). However, infertile patients with a high serum prolactin did not have a mid-luteal phase progesterone level different from those with normal prolactin. There was no correlation between prolactin and progesterone levels.