BLOOD-PRESSURE PATTERNS IN NORMAL-PREGNANCY AND IN PREGNANCY-INDUCED HYPERTENSION, PREECLAMPSIA, AND CHRONIC HYPERTENSION

Objective: To compare the 24-hour blood pressure (BP) pattern in physi ologic pregnancy, pregnancy-induced hypertension, preeclampsia, and ch ronic hypertension. Methods: We investigated four groups of women with singleton pregnancy: 73 controls, 48 patients with pregnancy-induced hypertension, 38 with preeclampsia, and 53 with mild to moderate chron ic hypertension. The 24-hour BP monitoring was performed longitudinall y in controls and in patients with chronic hypertension, and at the ti me of diagnosis in those with pregnancy-induced hypertension or preecl ampsia. Results: Nineteen thousand eight hundred seventy-two BP measur ements were analyzed. In controls, the mean values of BP indices were lower than those first reported in nonpregnant women, and the acrophas e was always localized in the first part of the afternoon. In pregnanc y-induced hypertension and especially in preeclampsia, besides the obv ious quantitative increase in BP, circadian BF oscillations were less pronounced than in controls, and the severity of hypertension seemed t o favor the loss of diurnal rhythm. Conversely, in chronic hypertensio n, circadian oscillations were the same as in controls. Conclusion: St andardized 24-hour BP monitoring during pregnancy allows quantitative and qualitative evaluations of the hypertensive status. However, if su ch a technique is used routinely in every clinical setting, we should establish specific thresholds of normality for pregnancy.