Maternal Occupational Exposures and Adverse Pregnancy Outcomes: An Overview of Meta- Analysis

Background: Working pregnant women are exposed to numerous occupational exposures, some of which may adversely affect their reproductive health. We aimed to review the effects of maternal occupational exposures and adverse effects on the infants. Materials and Methods: In this overview, searches were done on the online databases of Scopus, EMBASE, Cochrane, Web of Science and Medline; with no language or time restrictions (up to December 2019) to find studies that assess the relationship between maternal occupational exposures and adverse pregnancy outcomes. Two independent researchers performed the search process and a supervisor judged any disagreement in this regard. Results: Women occupationally exposed to anaesthetic gases had increased risk of spontaneous abortion. Second study reported specific birth defects including limb defects, cleft lip and cleft palate neural tube defects, urinary tract defects and congenital heart defects. In the third study, increased risk of childhood brain tumors was seen following maternal occupational exposures to chlorinated solvents. In the fourth study, a positive relationship between maternal exposures to ambient air pollution with autism spectrum disorder. In the fifth study, a significant relationship between anesthetic gases and congenital malformation, chemotherapy agent and spontaneous abortion and between shift work and spontaneous abortion. In the sixth study, exposure to endocrine-disrupting chemicals, group at work showed an increased risk of LBW with the odds ratio of 1.25, 95% CI: 1.04, 1.49. In the seventh study, exposure to ambient air pollution increases the risk of stillbirth. In eight, a statistically significant association between childhood leukemia and parental occupation. Conclusion: Maternal occupational exposures can be can be leading risk factors for many adverse pregnancy outcomes and birth defects.