8245796 Effect of working hours and shift work on preterm birth among Australian women

<h3>Objective</h3> This study aimed to fill this gap by examining the association between pre-term birth and two key occupational risk factors: long working hours and shift work. <h3>Methods</h3> This study analysed data from the Australian Longitudinal Study on Women’s Health. A total of 2241 women employed during pregnancy, who reported 2522 singleton births between 1996 and 2018 were included in analysis. Mixed effects logistic regression was used to address potential dependencies among births from the same women. <h3>Results</h3> Long working hours were associated with increased pre-term birth risk after adjusting for socio-demographic factors (AOR:1.61, 95%CI: 1.02-2.55), but this association became non-significant after further adjustment for obstetric and general health-related factors (AOR 1.21, 95% CI: 0.76-1.92). Shift work was not associated with preterm birth in either crude or adjusted regression models (AOR 0.59, 95%CI: 0.31-1.13). Women having year 12 or below education (AOR 1.86, 95%CI: 1.04-3.31), current smokers (AOR 2.48, 95%CI: 1.17-5.25), gestational hypertension (AOR 2.75, 95%CI: 1.32-5.23), primiparity (AOR 2.02, 95% CI: 1.13-3.63), past history of asthma (AOR 2.01, 95%CI: 1.05-3.84) and without private health insurance (AOR 1.86, 95%CI: 1.14-3.05) had significantly increased odds of preterm birth. <h3>Conclusion</h3> This study initially found an association between working more than 40 hours per week and preterm birth after adjusting for socio-demographic factors. However, this association became non-significant after further adjustment for obstetric and general health-related factors. The findings suggest that comprehensive policies addressing chronic disease prevention and social inequalities are crucial for reducing preterm birth.