Colloid osmotic pressure changes during hypertensive pregnancy.

Colloid osmotic pressure (COP) was measured in maternal serum of normal and hypertensive gravidae, and in their amniotic fluid. Both normal and hypertensive gravidae in the third trimester at bed rest and those treated for hypertension have low COP. Likewise, postpartum women may have low serum COP values apparently unrelated to any disease process. Amniotic fluid COP is low in both normal and hypertensive gravidae. COP Measurements therefore, seemingly offers little information regarding the health of pregnant women. Serum COP may increase in some hypertensive gravidae receiving saline infusion, probably reflecting abnormal renal function and hypovolemia. High serum triglyceride values coexisting with low COP may represent hepatic efforts to produce other colloid osmotic-active substances in the semi-chronic situation, although our findings in the acute situation did not support this hypothesis.