The association between wildfire exposure in pregnancy and foetal gastroschisis: A population‐based cohort study

Abstract

Background Global climate change has led to an increase in the prevalence and severity of wildfires. Pollutants released into air, soil and groundwater from wildfires may impact embryo development leading to gastroschisis. Objective The objective of this study was to determine the association between wildfire exposure before and during pregnancy and the risk of foetal gastroschisis development. Methods This was a retrospective cohort study using The California Office of Statewide Health Planning and Development Linked Birth File linked to The California Department of Forestry and Fire Protection data between 2007 and 2010. Pregnancies complicated by foetal gastroschisis were identified by neonatal hospital discharge ICD‐9 code. Pregnancies were considered exposed to wildfire if the mother's primary residence zip code was within 15 miles to the closest edge of a wildfire. The exposure was further stratified by trimester or if exposed within 30 days prior to pregnancy. Multivariable log‐binomial regression analyses were performed to estimate the association between wildfire exposure in each pregnancy epoch and foetal gastroschisis. Results Between 2007 and 2010, 844,348 (40%) births were exposed to wildfire in California. Compared with births without wildfire exposure, those with first‐trimester exposure were associated with higher rates of gastroschisis, 7.8 vs. 5.7 per 10,000 births (adjusted relative risk [aRR] 1.28, 95% confidence interval [CI] 1.07, 1.54). Furthermore, those with prepregnancy wildfire exposure were also found to have higher rates of gastroschisis, 12.5 vs. 5.7 per 10,000 births, (aRR 2.17, 95% CI 1.42, 3.52). In contrast, second‐ and third‐trimester wildfire exposures were not associated with foetal gastroschisis. Conclusions Wildfire exposure within 30 days before pregnancy was associated with more than two times higher risk of foetal gastroschisis, whereas a 28% higher risk was demonstrated if exposure was in the first trimester.

Birth Outcomes, Health, and Health Care Needs of Childbearing Women following Wildfire Disasters: An Integrative, State-of-the-Science Review

“…study, 38 which used feeding an infant 0–36 months of age at the time of exposure to wildfire as inclusion criteria. Eight studies focused on local populations exposed to a single, specific wildfire event, 23 – 25 , 28 , 34 , 37 – 39 whereas seven focused on longer term exposure to wildfire smoke across fire seasons over a span of years, 27 , 30 – 32 , 35 , 36 and one focused on exposure to mega-fire flame zones (that is, fires over 100,000 acres in size). 29 …”

“…All quantitative studies, as well as the quantitative component of the O’Donnell 23 mixed-methods study, used local administrative neonatal collections for birth statistics. Maternal residential address, 23 , 24 , 32 , 34 ZIP code, 27 , 30 , 33 county, 28 , 29 or maternal municipality 31 , 35 , 36 at time of birth were used as a proxy for nearness to fires or smoke. Each study used a different method to determine exposure to the wildfire disaster or wildfire smoke hazard, including a mix of land-based geographical borders, 23 – 25 , 29 , 30 satellite-based imagery or models, 27 , 28 , 31 – 36 land-based air quality monitors, 27 , 31 , 33 – 36 and personal air quality monitors within specific coordinates.…”

“…Two studies examined the association between exposure to wildfire and birth defects. 30 , 31 One study of wildfire exposure in California between 2007 and 2010 reported that first trimester exposure, in comparison with no exposure, was associated with higher rates of gastroschisis: 7.8 vs. 5.7 per 10,000 births ( ; 95% CI: 1.07, 1.54). 30 This study also found that prepregnancy wildfire exposure (up to 30 d before pregnancy) compared to no prepregnancy exposure resulted in higher rates of gastroschisis: 12.5 vs. 5.7 per 10.000 births ( ; 95% CI: 1.42, 3.52).…”

Wildfires in Pregnancy: Potential Threats to the Newborn

“…In this special issue on Climate Change and Reproductive, Perinatal, and Paediatric Health in Paediatric and Perinatal Epidemiology , Park and colleagues 4 provide an investigation of wildfire exposure during pregnancy and risk of gastroschisis in a large cohort of births from 2007 to 2010 in California. They found that residential proximity (<15 miles) to wildfires in the first trimester was associated with a 28% higher risk (relative risk 1.28, 95% confidence interval: 1.07–1.54) of gastroschisis based on ICD‐9 codes from state‐wide data.…”

Impacts of climate change on reproductive, perinatal and paediatric health

“…In the western United States, the frequency and intensity of wildfires have increased dramatically over the past two decades. The manuscript by Park and colleagues 7 links wildfire exposure to foetal gastroschisis, an abdominal wall defect that is rare, but increasing in prevalence. Gastroschisis has been associated with air pollution in some, but not all previous studies.…”