Growth hormone secretion during termination of pregnancy. Further evidence of a placental variant.

Serum profiles of growth hormone (GH), hPL and hCG were recorded in 5 pregnant women during termination of pregnancy at cesarean section and legal abortion. Two monoclonal antibodies directed against different epitopes on the GH molecule were used to distinguish the pituitary 22K-GH from the placental GH variant. After placental removal at cesarean section, a rapid fall in GH as well as in hPL and hCG concentrations was recorded. On the other hand GH levels were unaffected when early pregnancy was terminated by legal abortion. The importance of an intact placental function for the maintenance of high GH levels lends further support to the concept that a placental GH variant is produced during late pregnancy.