Investigation of Association between Environmental and Socioeconomic Factors and Preterm Birth in California

摘要

Background/Aim: Preterm birth (PTB), defined as gestational age < 37 weeks, is a significant cause of newborn morbidity and mortality. Relationships have been identified between PTB and environmental/chemical exposures, and social factors. However, fewer studies evaluate the joint effects of environmental exposure and social factors upon PTB. This study aims to 1) investigate relationships between singleton preterm birth and environmental exposures and socioeconomic factors across California; and 2) examine potential combined effects of environmental justice indicators upon PTB. Methods: We matched data from CalEnviroScreen 3.0 with the California's Office of Statewide Health Planning and Development (OSHPD) birth cohort datasets from 2009-2012 based on census tract geographic identifiers. We then statistically analysed associations between PTB and different tract-level environmental or social indicators including pollution exposures, environmental conditions, sensitive populations and socioeconomic status (SES), adjusted by birth race/ethnicity and maternal information such as age, education and insurance coverage. Results: We restricted our analysis to 1,432,627 eligible births with PTB rate 6.88%. We observed that some drinking water contaminants were positively associated with PTB. For example, the mean average arsenic concentration in drinking water of maternal residence for PTB was significantly higher than that for term birth (0.035 ppb, 95% C.I. [0.023, 0.048]). Tract-level SES also had significant association with PTB. Particularly, mothers who delivered preterm tended to reside in less educated neighbourhoods that had higher population percentage with < 12 years education (1.276 percent increase, 95% C.I. [1.168, 1.384]). Results from logistic regression models showed that individual race/ethnicity and insurance coverage could be potential effect modifiers. Conclusion: PTB is associated with both environmental exposure and socioeconomic factors in California.