Differences in circadian pattern of ambulatory pulse pressure between healthy and complicated pregnancies.

With the use of ambulatory monitoring, a circadian blood pressure pattern has been shown to characterize normotensive as well as hypertensive pregnant women. However, the potential differences between healthy and complicated pregnancies in pulse pressure, an independent marker of cardiovascular risk in the general population, have not yet been investigated. We analyzed 2523 blood pressure series sampled for 48 hours once every 4 weeks from the first obstetric visit until delivery in 245 women with uncomplicated pregnancies, 140 with gestational hypertension, and 49 who developed preeclampsia. Compared with uncomplicated pregnancies, a statistically significant elevation in the 24-hour mean of pulse pressure is found in complicated pregnancies in all trimesters (P<0.001). Results further indicate similar 24-hour mean of pulse pressure between gestational hypertension and preeclampsia in the first trimester of pregnancy (P=0.158). The increase in pulse pressure among women who developed preeclampsia compared with women with gestational hypertension, although small, was statistically significant in the second trimester (1.4 mm Hg; P=0.010) and, to a larger extent, in the third trimester of pregnancy (1.8 mm Hg; P<0.001). The differences in pulse pressure between healthy and complicated pregnancies, observed already in the first trimester of gestation, are found when systolic and diastolic blood pressure for women with a later diagnosis of gestational hypertension or preeclampsia are within the accepted range of normotension. Moreover, ambulatory pulse pressure provides higher sensitivity than clinic measurements for the diagnosis of hypertension in pregnancy.