What does an elevated mean arterial pressure in the second half of pregnancy predict--gestational hypertension or preeclampsia?

OBJECTIVE: The purpose of this study was to determine the predictive value of elevated mean arterial pressure in the second half of pregnancy for both preeclampsia and gestational hypertension. STUDY
DESIGN: This was a cohort of 588 nulliparous pregnant women studied prospectively from the twentieth week until delivery. Mean arterial pressure was obtained by means of a random-zero sphygmomanometer at 20, 26, and 31 weeks of gestation. The best cutoff point for the determination of predictive values was established by a receiver-operator characteristic curve.
RESULTS: Patterns of mean arterial pressure throughout pregnancy were different between preeclamptic and gestational hypertensive women. Receiver-operator characteristic curves for mean arterial pressure showed better predictive capacity for gestational hypertension than for preeclampsia. Sensitivity of mean arterial pressure to predict preeclampsia ranged between 39% and 48%, whereas for prediction of gestational hypertension it varied from 72% to 92%. Specificities for both groups were moderate (60% to 86%). Positive predictive values were low for all groups (5% to 33%).
CONCLUSION: Elevated mean arterial pressure in the second half of pregnancy is a good predictor of gestational hypertension but is a poor predictor of preeclampsia.