Prehypertension in Pregnancy and Risks of Small for Gestational Age Infant and Stillbirth

Abstract

Abstract-It is not fully known whether maternal prehypertension is associated with increased risk of adverse fetal outcomes, and it is debated whether increases in blood pressure during pregnancy influence adverse fetal outcomes. We performed a population-based cohort study in nonhypertensive women with term (≥37 weeks) singleton births (n=157 446). Using normotensive (diastolic blood pressure [DBP] <80 mm Hg) women as reference, we calculated adjusted odds ratios with 95% confidence intervals between prehypertension (DBP 80-89 mm Hg) at 36 gestational weeks (late pregnancy) and risks of a small-for-gestational-age (SGA) birth or stillbirth. We further estimated whether an increase in DBP from early to late pregnancy affected these risks. We found that 11% of the study population had prehypertension in late pregnancy. Prehypertension was associated with increased risks of both SGA birth and stillbirth; adjusted odds ratios (95% confidence intervals) were 1.69 (1.51-1.90) and 1.70 (1.16-2.49), respectively. Risks of SGA birth in term pregnancy increased by 2.0% (95% confidence intervals 1.5-2.8) per each mm Hg rise in DBP from early to late pregnancy, whereas risk of stillbirth was not affected by rise in DBP during pregnancy. We conclude that prehypertension in late pregnancy is associated with increased risks of SGA birth and stillbirth. Risk of SGA birth was also affected by rise in DBT during pregnancy. Our findings provide new insight to the relationship between maternal blood pressure and fetal well-being and suggest that impaired maternal perfusion of the placenta contribute to SGA birth and stillbirth. (Hypertension.

Maternal hemodynamics in screen‐positive and screen‐negative women of the ASPRE trial

“…The decline in SV throughout gestation could not be compensated by the rise in HR, resulting in mild drop in CO. PVR remained static across gestation in screen-positive women, a failure of the cornerstone of hemodynamic maternal adaptation in early pregnancy. Previous studies on maternal hemodynamics, performed in either hypertensive populations [27][28][29] or in normotensive cohorts [10][11][12][30][31][32][33][34][35][36] , had similar findings of low CO and raised PVR in pregnancies with FGR.…”

Risk factors of pre‐hypertension and hypertension among non‐pregnant women of reproductive age in northeastern Tanzania: a community based cross‐sectional study

“…The influence of pre‐HT on birth outcomes in SSA is not clear but recent reports from higher income countries have reported that pre‐HT early in pregnancy was associated with an increased risk of small for gestation age, pregnancy induced hypertension, neonatal sepsis and perinatal mortality . Therefore, without appropriate intervention, over one third of women in our study could potentially be at risk of adverse pregnancy outcomes.…”

Drinking Water Sodium and Elevated Blood Pressure of Healthy Pregnant Women in Salinity-Affected Coastal Areas

“…This is of particular interest because blood pressure is directly related to adverse pregnancy outcomes and may increase the chance of lowfor-gestational-age births. 29,30 Although in monsoon season women can often rely on rainwater, they will have to switch to a higher saline source if their pregnancy also covers (part of) the dry season. The increases in blood pressure that can be caused by this change in source could significantly increase the risk of adverse pregnancy outcomes especially because such increase would push the blood pressure of the women into the (pre)hypertensive range.…”