Study on Plasma Prolactin and Immunoreactive‐Prolactin Released from Decidua in Normal Pregnancy and Abortion

We investigated plasma prolactin (PRL) and immunoreactive-PRL (IR-PRL) released from decidua in vitro both in normal pregnancy and in inevitable abortion at 5 to 14 weeks of gestation. The plasma PRL level of normal cases in early pregnancy was 28.7 ± 2.1 ng/ml and that of abortion was 17.4 ± 1.9 ng/ml. The decidual PRL level of 23 normal cases was 320.1 ± 37.5 ng/100mg wet weight (w w) during 90-minute incubation and that of 11 abortive cases was 259.8 ± 59.1 ng/100mg w w, lower than that of normal cases, but not significantly. The gel filtration pattern of decidual PRL by column chromatography was more similar to amniotic fluid PRL than to maternal plasma PRL. These results suggest that there is little interaction between decidual and pituitary PRL, and between decidual PRL and placental function.