HIGH-SENSITIVITY TEST FOR THE EARLY DIAGNOSIS OF GESTATIONAL HYPERTENSION AND PREECLAMPSIA .2. CIRCADIAN BLOOD-PRESSURE VARIABILITY IN HEALTHY AND HYPERTENSIVE PREGNANT-WOMEN

The aim of this study was to describe the circadian pattern of non-inv asive ambulatorily monitored blood pressure during the trimesters of p regnancy in clinically healthy women as well as in pregnant women who developed gestational hypertension or preeclampsia, and to compare sen sitivity and specificity of diagnosis based on the average of the bloo d pressure series with the values obtained on the basis of casual meas urements. We analyzed a total of 745 blood pressure series sampled by ambulatory monitoring for about 48 hours in each of several occasions in 189 women with uncomplicated pregnancies, 71 with gestational hyper tension, and 29 with preeclampsia. The circadian pattern of BP variati on for each group (complicated vs. uncomplicated pregnancies) and trim ester of gestation was established by linear least-squares methods. Hi ghly statistically different circadian patterns are demonstrated for s ystolic, mean arterial and diastolic blood pressure for both groups of pregnant women in all trimesters (P < 0.001 in all cases). Blood pres sure decreases from the first trimester to the second and raises again in the third for healthy pregnant women, but continuously increases d uring gestation in women who developed gestational hypertension or pre eclampsia. The differences in circadian rhythm-adjusted mean between c omplicated and uncomplicated pregnancies are highly statistically sign ificant in air trimesters (P < .001). Sensitivity and specificity of d iagnosing gestational hypertension based on the circadian mean are 73% and 48%, respectively, too low for a proper individualized diagnosis of gestational hypertension or preeclampsia. This study confirms the p redictable circadian variability in blood pressure during gestation. T he differences between healthy and complicated pregnancies can be obse rved as early as in the first trimester of pregnancy, but the use of t he 24-hour mean BP does not provide a good approach for early diagnosi s of gestational hypertension or preeclampsia.