Maternal long working hours and offspring's weight-related outcomes: A systematic review and meta-analysis

It is unclear whether maternal working time has an impact on offspring's weight-related outcomes especially obesity; the objective of this study is to conduct the first meta-analysis to focus on this topic. We searched PubMed, Ovid, and Web of Science databases through August 2021. A random-effect model was used to assess the pooled odds ratios (ORs) and regression coefficients (β) with their corresponding 95% confidence intervals (95% CIs). Subgroup analyses were conducted to explore sources of heterogeneity. Publication bias was evaluated by the Egger's tests. Twenty-two observational studies were included with a total of 191,420 participants. Compared with children whose mothers worked less than 35 h/week, we found that children whose mothers worked more than 35 to 40 h/week had a 2.24-fold increased risk of childhood overweight/obesity (OR = 2.24, 95% CI: 1.61-3.11). An increment of 10 h/week in maternal working was associated with an approximately 1.0 percentage points in the probability of childhood overweight/obesity (β = 0.008, 95% CI: 0.004-0.012). The pooled OR also indicated a similar result (OR = 1.09, 95% CI: 1.04-1.15). In addition, an increment of 10 h/week in maternal working was associated with 0.029 units increase in offspring's BMI z score (β = 0.029, 95% CI: 0.016-0.042). Maternal long working hours is a potential risk factor for offspring's weight-related outcomes. Measures should be taken to protect the work welfare of females, thus facilitating the positive interaction of individual-family-society.