Job strain and adverse pregnancy outcomes: A scoping review and meta-analysis

Previous studies have shown that job strain is associated with low birthweight (LBW), preterm birth (PTB), and small for gestational age (SGA). We conducted a scoping review and meta-analysis to assess the association between job strain and adverse pregnancy outcomes.

A literature search was performed on PubMed. We included English-language studies that examined the association between job strain (based on the Karasek demand-control model) and pregnancy outcomes. We excluded letters, posters, reviews, and qualitative studies. Random effects meta-analysis was performed. Heterogeneity was assessed using τ² and I² statistics. Potential bias was assessed using standard funnel plots. Asymmetry was evaluated by Egger's test. Leave-one-out analysis was performed for sensitivity analyses.

Three eligible studies were found for LBW, seven for PTB, and four for SGA. The number of subjects ranged from 135 to 4889, and the prevalence of high job strain ranged from 6.64% to 33.9%. The pooled odds ratio and 95% confidence interval (CI) for LBW, PTB, and SGA were 1.23 (95% CI: 0.97, 1.56), 1.10 (95% CI: 1.00, 1.22), and 1.16 (95% CI: 0.97, 1.39) respectively, indicating modest associations. Heterogeneity for LBW and PTB may not be important but may be moderate for SGA. No publication bias was detected for LBW and PTB, but possible publication bias exists for SGA.

We found a modest association between job strain and PTB. Since job strain is only one of the many aspects of an unhealthy work environment, interventions that improve working conditions more broadly are needed.