Maternal workplace emotional stressors and physical activity and adverse birth outcomes

Laura J Lee, The University of Texas School of Public Health


Preterm birth (PTB) and being born small-for-gestational age (SGA) are major contributors to infant mortality and morbidity in the U.S. Several risk factors for PTB and SGA have been identified, but the identification of additional risk factors is important for identifying future prevention targets. Maternal occupational exposures such as heavy lifting have been suggested as potential risk factors for PTB and SGA. Despite increasing epidemiological literature on certain work activities and adverse birth outcomes, the role of many domains of occupational physical activities (e.g., bending) and emotional stressors (e.g., dealing with unpleasant or angry people) on adverse birth outcomes remain unknown. Using data from the National Birth Defects Prevention Study (NBDPS), specifically infants born with no major birth defects, we 1) described estimated maternal occupational physical activities, sedentary behaviors, and emotional stressors during pregnancy and 2) examined the role of a wide range of maternal occupational physical activities and emotional stressors in each trimester of pregnancy on PTB and SGA. Information on multiple domains of occupational exposures was gathered by linking mother’s self-reported jobs to the U.S. Department of Labor’s Occupation Information Network (O*NET). Additionally, factor analysis was utilized to address the issue of correlated individual occupational activities. Regarding maternal occupational exposures during pregnancy, this study suggested that the most frequent estimated physical activity associated with jobs during pregnancy was standing. Of 6,337 mothers, 31% reported jobs associated with standing for ≥75% of their time. The most common source of emotional stressors was dealing with unpleasant or angry people, estimated to occur ≥75% of the time in jobs reported by 10.3% of mothers. There was significant variability in estimated occupational exposures by maternal age, race/ethnicity, and educational level. For the main study question on the role of maternal occupational physical activity and emotional stressors on PTB and SGA, mothers who reported jobs in the highest quartile of occupational physical activity were 36% more likely to have a child being born SGA than mothers who reported jobs in the lowest quartile (95% confidence interval 1.02, 1.82; P for trend = 0.001). No other significant associations were observed. These studies expand our understanding about the associations between work exposures and certain adverse birth outcomes relative to previous studies of more limited scope and our findings may ultimately 1) help women of reproductive age in various occupations to decrease their risk of adverse birth outcomes and 2) inform employers to better accommodate pregnant workers from potentially hazardous occupational activities.

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Recommended Citation

Lee, Laura J, "Maternal workplace emotional stressors and physical activity and adverse birth outcomes" (2015). Texas Medical Center Dissertations (via ProQuest). AAI10046722.