Plasma concentrations of four pregnancy proteins in complications of pregnancy.

Toxemia of pregnancy was associated with an elevation of the pregnancy-associated plasma protein (PAPP)-A concentration, as compared to the level in normal pregnancy in the last month of gestation. The other pregnancy proteins measured were not altered in toxemia. In twin pregnancies, the PAPP-A, PAPP-C, and human placental lactogen levels were all increased, particularly PAPP-A. On the other hand, pregnancy zone protein was not affected by twinning. Pregnancy with diabetes showed normal levels of these proteins.