Blood Pressure Patterns in Normal Pregnancy, Gestational Hypertension, and Preeclampsia

Abstract

Abstract-With the aim to describe the daily pattern of blood pressure during the trimesters of pregnancy in clinically healthy women as well as in pregnant women who developed gestational hypertension or preeclampsia, we analyzed 1494 blood pressure series systematically sampled by ambulatory monitoring for 48 hours every 4 weeks after the first obstetric visit in 124 women with uncomplicated pregnancies, 55 with gestational hypertension, and 23 with a final diagnosis of preeclampsia. The circadian pattern of blood pressure variation for each group and trimester of gestation was established by population multiple-component analysis. A highly statistically significant circadian pattern represented by a linear model that includes components with periods of 24 and 12 hours is demonstrated for systolic and diastolic blood pressure for all groups of pregnant women in all trimesters (PϽ0.001 in all cases). The differences in circadian rhythm-adjusted mean between complicated and uncomplicated pregnancies are highly statistically significant in all trimesters (always PϽ0.001). There is also a statistically significant difference in circadian amplitude (extent of daily change) of blood pressure between healthy and complicated pregnancies in all trimesters (always PϽ0.004).Results further indicate similar circadian characteristics between women who later developed gestational hypertension or preeclampsia in the first trimester of pregnancy. The difference between these 2 groups in circadian mean is statistically significant in the second trimester for systolic (Pϭ0.022) but not for diastolic blood pressure (Pϭ0.986).In the third trimester, the difference in circadian mean is highly statistically significant for both variables (PϽ0.001).The differences in blood pressure between healthy and complicated pregnancies can be observed as early as in the first trimester of pregnancy. Those highly significant differences are found when both systolic and diastolic blood pressure for women with a later diagnosis of gestational hypertension or preeclampsia are well within the accepted normal physiological range of blood pressure variability. These differing changes in the circadian pattern of blood pressure with advancing gestational age between healthy and complicated pregnancies offer new end points that may lead to an early identification of hypertensive complications in pregnancy as well as to the establishment of prophylactic intervention. Key Words: blood pressure Ⅲ circadian rhythm Ⅲ pregnancy Ⅲ hypertension, gestational Ⅲ normotension Ⅲ preeclampsia B lood pressure (BP) assessment in pregnant women has relied mostly on a few measurements taken in the physician's office. These casual time-unspecified measurements perform poorly, even in the third trimester of pregnancy, in selection of a population for potential detection of preeclampsia. 1-6 Isolated BP measurement is, however, still the mainstay of the diagnosis of preeclampsia. The use of a reliable and accurate automated device for ambulatory BP monitoring (ABPM) is the l...

Melatonin secretion is impaired in women with preeclampsia and an abnormal circadian blood pressure rhythm

“…11,36,37 In the present study, the prevalence of sleep hypertension among 31 women with preeclampsia was 68%. Furthermore, we found that non-dippers and dippers with preeclampsia differ not only in their hemodynamic response during night, but also in their physiological response to darkness, as shown by the blunted nocturnal melatonin secretion in non-dippers.…”

Additive value of standard ECG for the risk prediction of hypertensive disorders during pregnancy

“…It is well recognized that a relatively large proportion of pregnant women may have masked gestational hypertension, undetected by office BP measurements, but revealed by specific BP index or circadian patterns computed with ambulatory BP monitoring. [31][32][33] Notably, pregnant women at increased risk of hypertension disorders tend to have higher night-time ambulatory BP than women without development of hypertension complications during pregnancy. 33 At the same time, night-time ambulatory BP is an independent predictor of LA size in hypertensive patients.…”

“…[31][32][33] Notably, pregnant women at increased risk of hypertension disorders tend to have higher night-time ambulatory BP than women without development of hypertension complications during pregnancy. 33 At the same time, night-time ambulatory BP is an independent predictor of LA size in hypertensive patients. 34 In this context, the presence of an abnormal P wave at ECG in the early phase of gestation could be considered as a marker of high or high-normal BP values in women with normal BP detected in the office, and consequently refine the predicted risk of hypertensive disorders.…”

High Blood Pressure Before and During Early Pregnancy Is Associated With an Increased Risk of Gestational Diabetes Mellitus

“…During normal pregnancy, BP steadily decreases up to 21 weeks' gestation and then increases during the second half of pregnancy (14). Our assessment of hypertension during pregnancy probably only captured severe case subjects in whom BP remained elevated even during early pregnancy.…”