Circadian rhythm of maternal blood pressure and fetal growth

Abstract

This study aimed at examining any relation between the circadian variation in blood pressure (BP) in human pregnancy and fetal growth. A prospective study included 52 pregnant women monitored during the third trimester of pregnancy. There were 33 uncomplicated pregnancies with normal fetal growth (Group 1) and 19 pregnancies complicated by intrauterine growth retardation (IUGR), confirmed at birth (Group 2). Ten women (five in each group) had pregnancy-induced hypertension. All women were hospitalized and followed a similar daily routine. BP was recorded with an automatic wearable device. Measurements were obtained every 20 min for 24 ± 1 h. BP profiles were analyzed by conventional statistical methods and by cosinor, involving the least squares fit of cosine curves with an anticipated period (24 h) to the data. BP parameters, fetal outcome, demographic and obstetric characteristics were compared between the two groups. Logistic regression and multivariate analyses were used to assess factors putatively associated with fetal outcome. The circadian amplitude of diastolic BP was found to be larger in normotensive women with IUGR. As gauged by odds ratios (OR), the circadian amplitude of diastolic BP (OR = 1.7, 95% CI: 1.1-2.8; P = 0.03) and hematocrit (OR = 1.4, 95% CI: 1.0-1.9; P = 0.04) were the only variables positively and independently associated with IUGR. In the presence of maternal hypertension, the circadian amplitude of systolic BP was negatively associated with IUGR (OR = 0.7, 95% CI: 0.5-1.0; P = 0.03). A larger circadian variation in diastolic BP, rather than a difference in the mean value of systolic or diastolic BP, was found to be statistically significantly associated with IUGR. This study adds another condition in which the circadian BP amplitude constitutes a harbinger of elevated risk, apart from an association with a shortened lifespan in the absence or presence of malignant hypertension and with an increased risk of stroke and nephropathy reported earlier.

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

“…51 In addition, the non-dipping pattern of circadian BP has been associated with a large increase in cardiovascular morbidity, reflecting an increased risk of target organ damage. 54 Our results showed a decreased melatonin secretion in women with a recent history of preeclampsia and nocturnal hypertension. This finding suggests that melatonin rhythm may be involved with the outcome of women with a history of preeclampsia and nocturnal hypertension.…”

Effect of rotating shift work on childbearing and birth weight: a study of women working in a semiconductor manufacturing factory

“…[2] In contrast, rotating shift work exposure can compromise the health of early middle-aged female workers, [3][4][5] an important population giving birth in industrialized countries. Although studies in some workplace settings have found adverse effects of shift work exposure on reproductive disorders of female employees [6,7] and on birth weight of fetuses, [8,9] few studies have investigated these effects in semiconductor manufacturing factories.…”

A chronobiological policy to decrease the burden of hypertension and obesity in low- and middle-income population

“…The value of this study is that it illustrates the importance of measuring diagnostic markers of a disease in asymptomatic individuals, so enabling treatment to begin before the disease becomes established (Gupta et al 2008). Also, Maggioni et al (Maggioni et al 2005) studied 52 pregnant women and monitored their BP every 20 min for about 24 h; they showed that, in normotensive individuals, the amplitude of their circadian rhythm of diastolic BP was associated with intrauterine growth retardation and that, in hypertensive individuals, the amplitude of the circadian rhythm of systolic BP was negatively associated with intrauterine growth retardation.…”