Predictive value of increased plasma levels of fibronectin in gestational hypertension.

Blood pressure, proteinuria, and plasma fibronectin and plasminogen activator inhibitor-1 levels were measured in 120 apparently healthy normotensive primigravid women during the first, second, and third trimesters of pregnancy and 2 days post partum. Thirty-two women developed hypertension (diastolic blood pressure greater than or equal to 90 mm Hg) that in 17 women was associated with proteinuria (greater than 0.3 gm/day). Fibronectin levels were 83% +/- 22% of normal (mean +/- SD) during the first trimester and 75% +/- 20% at term in the healthy women but increased from 94% +/- 36% to 187% +/- 36% in the women who developed gestational hypertension (with or without proteinuria) (p less than 0.0001). Plasminogen activator inhibitor-1 levels increased from 26 +/- 19 ng/ml to 110 +/- 86 ng/ml in healthy women and from 32 +/- 35 ng/ml to 290 +/- 90 ng/ml in hypertensive women (p less than 0.001). Increased levels of fibronectin at 25 to 36 weeks of pregnancy (greater than or equal to mean + 2 SD of the healthy women, or greater than 140%) were found in 31 of the 32 women with gestational hypertension with or without proteinuria and in 5 of the 88 healthy women (sensitivity 96%, specificity 94%). Fibronectin levels increased 3.6 +/- 1.9 weeks earlier than the onset of hypertension and/or proteinuria. Increased levels of plasminogen activator inhibitor-1 at 25 to 32 weeks (greater than or equal to 280 ng/ml) were found in 16 of the 32 women who developed gestational hypertension with or without proteinuria and in 4 of the 88 healthy women (sensitivity 50%, specificity 95%). We conclude that increased fibronectin levels are the best predictor of gestational hypertension with or without proteinuria and that its level in plasma increases several weeks before the development of hypertension.