Self-Reported Oil Spill Exposure and Birth Outcomes: The Growh Study

Abstract

Background: The chemical, economic, and social effects of a major oil spill might affect pregnancy health. Methods: Between 2012 and 2016, 1444 women reported their involvement with the 2010 Gulf of Mexico oil spill, as well at least one livebirth. Indicators of oil spill exposure included financial consequences, direct contact with oil, traumatic experiences, loss of use of the coast, and involvement in litigation. Birth outcomes studied were low birthweight (LBW; birthweight <2500 g) and preterm birth (PTB; >3 weeks early), either obtained as self-reported information or abstracted from medical records if the woman was still pregnant at the time of the interview. All pregnancies prior to the oil spill were considered unexposed; those after the oil spill were considered exposed or unexposed depending on interview responses. Generalized estimating equations with a logit link and adjustment for confounders were used to assess the relationship between oil spill exposure and these outcomes.Results: 370 (13.2%) of pregnancies were reported as ending in LBW, while 273 (9.7%) as ending in PTB. Births after the oil spill were not more likely to end in either outcome (adjusted odd ratio, 0.96, 95% CI 0.73-1.24 and 0.98, 0.72-1.33). Financial consequences, trauma, use of coast, and litigation were not associated with worse birth outcomes (ORs between 0.8 and 1.2). Risk of preterm birth was raised in the group with most contact with oil (aOR 2.30, 1.16-4.59), although sensitivity analyses did not indicate this result was robust to other assumptions.Conclusions: Self-reported exposure to most aspects of the Gulf oil spill were not associated with adverse birth outcomes. The raised risk for PTB among those in contact with oil warrants examination in studies with more detailed assessment of exposure.