Role of maternal prolactin in early pregnancy failure.

To study the significance of maternal prolactin (PRL) secretion in early pregnancy failures, intravenous thyrotropin-releasing hormone (TRH) stimulation tests were carried out in 39 women with normal or doomed early pregnancy, as verified by ultrasound examination, before the onset of clinical symptoms of abortion. The basal PRL levels did not differ between the women with normal early pregnancy (N = 15), blighted ovum (N = 13), or with missed abortion (N = 11). Thyrotropin-releasing hormone injection stimulated PRL secretion in all cases, but the response was smaller (P less than .01) in women with early pregnancy failure. It is concluded that PRL is not significant in the etiology or course of early pregnancy wastage and that its basal or stimulated measurement is of limited value in the prediction of pregnancy outcome.