Plasma prostaglandins in pregnancy.

Plasma prostaglandins were determined by radioimmunoassay in 92 pregnant and 14 nonpregnant women. There was significant elevation of PGA-like material in the first trimester of pregnancy (1744 pg/ml) over that seen in nonpregnant women (576 pg/ml) with continuation of that elevation in the second and third trimesters. No significant difference existed among PGE levels of the nonpregnant group (251 pg/ml) and the first two trimesters of pregnancy (384 pg/ml and 294 pg/ml); the PGE level of the third trimester group (443 pg/ml) was significantly elevated over that of the nonpregnant group. PGF levels remained constant during all trimesters (135 pg/ml, 144 pg/ml, and 130 pg/ml) but exhibited plasma concentrations significantly higher than the nonpregnant group (78 pg/ml). Potential role (s) of prostaglandins as mediators of cardiovascular and renal changes of pregnancy are discussed.