Perinatal outcomes, blood pressure patterns and risk assessment of superimposed preeclampsia in mild chronic hypertensive pregnancy

Abstract

Objective: Assessment of perinatal outcomes, blood pressure (BP) patterns and risk of superimposed preeclampsia in a population with mild chronic hypertension.

Study design: We investigated 223 pregnant women with mild chronic hypertension and 200 controls. Twenty-four-hour BP monitoring longitudinally in pregnancy and Doppler assessment of uterine arteries at 24 weeks' gestation were performed. Perinatal outcomes were recorded.

Results: Superimposed preeclampsia occurred in 28.4% of hypertensive women, with an increased rate of small-for-gestational age babies (30.7% versus 8.9%), a lower birth weight (2587.75+/-832.97 versus 3167.35+/-536.3; p < 0.001) and a higher rate of caesarean sections (69.2% versus 35.5%) than controls. According to the ROC curve, the mean 24-h blood pressure (diastolic 78 mmHg [S.E.: 0.95; SP: 0.89] and systolic 121 mmHg [S.E.: 0.88; SP: 0.92]) and the mean resistance index of the uterine arteries of 0.52 (S.E.: 0.69; SP: 0.87) are better prognostic values for predicting superimposed preeclampsia.

Conclusions: In women with chronic hypertension in the second trimester 24-h blood pressure monitoring and Doppler velocimetry of the uterine artery are able to detect those at risk of superimposed preeclampsia. In women with circulatory adaptation to pregnancy, a good perinatal outcome is expected with proper obstetric care.