Environment/Climate Change
Associations between gestational exposure to extreme heat events and early life blood pressure in North Carolina Sam J. Neally* Sam J. Neally Neally Neally Neally Neally Neally Neally Neally Department of Epidemiology, UNC Gillings School of Public Health
Background: Extended periods of high temperatures are associated with adverse cardiovascular health outcomes. Little is known on the relationship between gestational heat exposure and offspring cardiovascular health.
Aim: We examined associations of extreme heat events (EHE) during pregnancy with offspring early-life elevated blood pressure (BP).
Methods: The Newborn Epigenetics STudy (NEST, 2005-2011) is a birth cohort of 2,681 gestational parent-child pairs recruited from prenatal visits at obstetrics care facilities in Durham County, NC. We analyzed data from 1,067 participants with at least one BP measurement from 3 to 9 years and complete information on geographic residence and covariates. EHE were defined as mean daily apparent temperature ≥95th percentile for ≥2 consecutive days or ≥90th percentile for ≥3 consecutive days during each trimester of pregnancy within census block group of residence, with percentiles relative to NC temperatures from 2004-2012. Continuous systolic and diastolic BP from medical abstracts were converted to age-, sex-, and height-standardized national percentiles. Elevated BP was defined as ≥90th percentile.
Longitudinal logistic mixed effects regression models estimated OR and 95%CI for having at least one EHE during each trimester and elevated BP, adjusting for season of conception and gestational parent age, race, marital status, and education. Analyses were performed for the full sample, among term births (n=913), and among children whose gestational parent did not report hypertensive disorder during pregnancy (n=888).
Results: Prevalences of elevated BP ranged from 17-26% from ages 3 to 9 years. Imprecise associations were observed in the full sample. Among term births, having at least one compared to no EHE in the second trimester was associated with greater odds of elevated BP (OR:2.12, 95%CI=1.17-3.82).
Conclusions: Extreme heat experiences during certain periods of pregnancy may contribute to lifecourse cardiovascular outcomes.