Twenty-four-hour automated blood pressure monitoring as a predictor of preeclampsia

OBJECTIVE: The purpose of this study was to determine the predictive abilit y of parameters of 24-hour ambulatory blood pressure monitoring for the dev elopment of preeclampsia or gestational hypertension in women who are alrea dy considered at risk for these disorders. STUDY DESIGN: One hundred twenty-two pregnant women who were considered hig h risk for the development of preeclampsia underwent 24-hour ambulatory blo od pressure monitoring between 18 and 30 weeks gestation, while their condi tion was normotensive according to routine mercury sphygmomanometry. One hu ndred sixty-four healthy primigravid women who were considered at usual ris k for preeclampsia underwent the same tests as a parallel study. Routine bl ood pressure, awake and sleep average blood pressure, and 24-hour mean aver age blood pressure were entered into multiple logistic regression as predic tors of either preeclampsia or gestational hypertension; significant variab les were then tested by a series of receiver operator curves. RESULTS. Eight percent of usual risk and 45% of high risk women experienced the development of preeclampsia or gestational hypertension. In both group s, the average routine mercury blood pressure and awake, sleeping, and 24-h our ambulatory blood pressure monitoring-derived blood pressure were signif icantly higher in women who later experienced the development of preeclamps ia or gestational hypertension. In usual risk women, 24-hour systolic blood pressure of greater than or equal to 115 mm Hg and sleeping systolic blood pressure of greater than or equal to 106 mm Hg were predictive of later pr eeclampsia or gestational hypertension, but sensitivities were low (77% and 54%, respectively). In high risk women, sleeping diastolic blood pressure of greater than or equal to 62 mm Hg and sleeping mean arterial pressure of greater than or equal to 79 mm Hg were predictive of preeclampsia or gesta tional hypertension, but again sensitivities were low (70% and 65%, respect ively). CONCLUSION: Awake and sleeping blood pressure are higher in midpregnancy in women who later experience the development of preeclampsia or gestational hypertension. Twenty-four-hour ambulatory blood pressure monitoring provide s a noninvasive method of selecting some of these women, but this test has a sensitivity no better than that of other predictive tests, even in women at high risk for preeclampsia.