Shift work and long hours increase risk of preterm birth

Shift work and working long hours significantly increase the chances of preterm birth, however, most work roles can be modified to reduce this risk.

A Monash University-led study has found that pregnant women who worked long hours, shift work, physically demanding jobs, or in jobs that exposed them to whole-body vibration, were at increased risk of preterm birth.

Among women in work, the risk was 63 per cent higher for women whose jobs include shift work. It was 44 per cent higher for women who worked more than 40 hours per week than those who worked less than 40 hours.

The research review also found moderate non-quantifiable evidence that jobs involving high physical exertion or whole-body vibration were linked with preterm birth.

There was no evidence of increased risk for women who stood at work for long periods or whose jobs required heavy lifting, defined as lifting more than 5kg at a time or more than 50kg over the course of a day.

Published in Public Health Reviews, the systematic review and meta-analysis of 37 studies from 21 countries investigated the relationship between physical job risks and preterm birth before 37 weeks.

“This study is important because preterm birth has been linked with health complications for children such as diabetes, hypertension, lung and heart disease later in adulthood,” said study co-author and PhD student Haimanot Abebe Adane from Monash University’s School of Public Health and Preventive Medicine healthy working lives research group.

Preterm birth rates range from five to 18 per cent across 184 nations, and Adane said an estimated 15 million preterm births occur worldwide each year, with 1.1 million infant deaths as a result.

Study co-author, Professor Alex Collie also said the research review had important implications for both pregnant women and their employers.

“We know that work is generally good for health. We are not suggesting that pregnant women should not work,” said Professor Collie, who serves as director of the division of health systems, services and policy in the School of Public Health and Preventive Medicine at Monash University.

“This study shows that employers of pregnant women should consider modifying jobs that have heavy physical demands. Most jobs are able to be modified in some way to reduce exposure to physical tasks.

“It is also important that pregnant women who work in physically demanding jobs are aware of these findings. While everyone’s job is different, we hope the study can support conversations between employers and pregnant women about ways of reducing risks,” he said.

More than three-quarters of Australian women work throughout their reproductive age, a figure which has been growing in recent years as more women enter the workforce.

“As the number of Australian women in the workforce has increased, so has the number of women in physically demanding jobs,” Collie said.

“We need workplace policy and procedures that balance these risks while not limiting the workforce participation of women.”