Birth defects among offspring of California firefighters, 2007-2019

Prev Med. 2024 Sep:186:108080. doi: 10.1016/j.ypmed.2024.108080. Epub 2024 Jul 20.

Abstract

Purpose: Limited research examines birth defects from maternal or paternal firefighting exposure. This study aims to assess if maternal or paternal occupational exposure to firefighting during periconception is associated with offspring birth defects.

Methods: Data from California birth certificates (2007-2019) were linked to maternal / offspring hospitalization records. Occupation during the periconceptional period was categorized from vital statistics as the following: paternal non-firefighting (n = 4,135,849), paternal firefighting (n = 22,732), maternal non-firefighting (n = 3,332,255) and maternal firefighting (n = 502). Birth defects were identified using ICD codes, grouped by anatomical regions. Adjusted odds ratios were estimated, and sensitivity analyses explored police officer reference groups and detailed birth defect categories.

Results: Offspring of paternal firefighters had lower odds of circulatory defects (aOR = 0.9, 95% CI 0.8, 1.0), oral clefts (aOR = 0.6, 95% CI 0.4, 0.8) and respiratory defects (0.7, 95% CI 0.6, 0.9) compared to paternal non-firefighters. Associations between maternal firefighting and offspring birth defects were imprecise. Substituting police officers as the reference group attenuated findings.

Conclusions: Offspring of paternal firefighters may have similar or slightly lower birth defect odds compared to offspring of non-firefighters. Limited data was available for assessing maternal firefighting outcomes. Future studies should prioritize studies using occupational exposure matrices to limit misclassification of exposure.

Keywords: Birth defects; California population; Maternal and paternal firefighter occupation; Periconceptional period; Pregnancy.

MeSH terms

  • Adult
  • Birth Certificates
  • California / epidemiology
  • Congenital Abnormalities* / epidemiology
  • Female
  • Firefighters* / statistics & numerical data
  • Humans
  • Infant, Newborn
  • Male
  • Maternal Exposure / adverse effects
  • Maternal Exposure / statistics & numerical data
  • Occupational Exposure* / adverse effects
  • Occupational Exposure* / statistics & numerical data
  • Paternal Exposure / adverse effects
  • Paternal Exposure / statistics & numerical data
  • Pregnancy