HIGH-SENSITIVITY TEST FOR THE EARLY DIAGNOSIS OF GESTATIONAL HYPERTENSION AND PREECLAMPSIA .1. PREDICTABLE VARIABILITY OF CARDIOVASCULAR CHARACTERISTICS DURING GESTATION IN HEALTHY AND HYPERTENSIVE PREGNANT-WOMEN

The evaluation of predictable variability in blood pressure and heart rate by (a) the use of fully ambulatory devices, and (b) the proper pr ocessing of the time series thus obtained, can be useful in assessing early cardiovascular disease risk in pregnancy. We have used this appr oach to quantify a predictable time structure of blood pressure throug hout pregnancy in clinically healthy women as well as in pregnant wome n who developed gestational hypertension or preeclampsia. 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 unco mplicated pregnancies, 71 with gestational hypertension, and 29 with p reeclampsia. The pattern of variation along gestation of the 24-hour m ean of blood pressure for groups of normotensive and hypertensive preg nant women was established by polynomial regression analysis. Regressi on analysis revealed predictable patterns of variation of 24-hour mean s with gestational age: for normotensive pregnant women, results indic ate a steady decrease in blood pressure up to the 20th week of pregnan cy followed by an increase in blood pressure up to the day of delivery . Women with gestational hypertension or preeclampsia are characterize d, however, by a continuous linear increase of blood pressure with ges tational age, starting from the beginning of pregnancy. This study con firms and extends to ambulatory everyday life conditions the predictab le pregnancy-associated variability in blood pressure. The differences between uncomplicated and complicated pregnancies offer new endpoints for an early identification of gestational hypertension and preeclamp sia.