C1-esterase inhibitor in uncomplicated pregnancy and mild and moderate preeclampsia.

Routine coagulation tests and measurement of the plasma levels of C1-esterase inhibitor (C1-INH) and antithrombin III were performed in 17 women with mild preeclampsia, 10 women with moderate preeclampsia and 20 women with uncomplicated pregnancy. All pregnant probands were within the third trimester of pregnancy. 20 non-pregnant women were used as controls. The groups were matched in age and the pregnant ones were also matched in gestational age. C1-INH activity and antigen were significantly reduced (p less than 0.002) in normally pregnant women as compared with non-pregnant ones. Further, C1-INH activity was lower in women with mild preeclampsia and significantly lower in women with moderate preeclampsia (p less than 0.05) as compared with normally pregnant women. None of the plasmatic coagulation tests was indicative of a consumption reaction. We conclude that C1-INH activity and antigen reductions are commonly associated with pregnancy. Furthermore, as markedly lower values can be found in mild and moderate preeclampsia, measurement of the C1-INH activity in pregnant women within the third trimester might proof useful to establish the diagnosis of a preeclamptic condition.