Workers Health & Safety Centre

Work hazards linked to preterm births in pregnant workers, research

Working shifts and long hours significantly increase the risk of preterm births for pregnant workers, according to newly published research.
Researchers from Monash University in Melbourne, Australia performed a systematic review and meta-analysis of 37 studies from around the globe including United States and Canada to investigate the relationship between occupational exposures and preterm birth.  
According to the findings published in the October 2023 edition of the Public Health Reviews journal, pregnant women working more than 40 hours a week compared to those working less than 40 hours have a 44 per cent higher risk for preterm birth. Those working shifts have a 63 per cent higher risk. Furthermore, the findings showed a positive association between physical workload, whole-body vibration and preterm birth.

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Significant health impacts

While a typical pregnancy lasts 40 weeks, any birth prior to 37 weeks is defined as “preterm”. The earlier a baby is born the greater the risk to their immediate and long-term health. According to the Canadian Institutes for Health Research, for instance, preterm births accounts for almost two in three infant deaths. Respiratory distress, impaired brain growth, diabetes, heart disease, learning disabilities and cerebral palsy are just a few of the many additional health complications linked to preterm birth.     

Obligations to protect pregnant workers

“While everyone’s job is different, we hope the study can support conversations between employers and pregnant women about ways of reducing risks,” explained study co-author and Monash University professor Alex Collie in a press release about the research.
The researchers also suggest, “Employers and regulatory authorities have a responsibility to create policies and work practices that reduce the exposure of pregnant women to these hazards.”

Here in Canada, limited reassignment protection under occupational health and safety law is in place in Quebec and for workers under federal jurisdiction
(Part II and Division VII, Part III, Canada Labour Code).

Other jurisdictions, including Ontario, Manitoba and Saskatchewan, have some protection under human rights provisions. Ontario women, for instance, have a right to request changes to job duties or rules that affect their health when pregnant. Employers must accommodate these requests, unless doing so would cause undue hardship. The Ontario Human Rights Commission charged with enforcing these provisions look at each case and will determine any action based on its own merit.
In terms of occupational health and safety law in Ontario, specific protection for pregnant workers is limited. Health care employers, for instance, must implement measures to protect workers from exposure to a biological, chemical or physical agent that is or may be a hazard to a worker’s pregnancy [Health Care & Residential Facilities Regs., Sec. 9(8)].
Workers, their representatives and other advocates continue to press for more specific occupational health and safety regulatory protections for pregnant women and nursing mothers in all sectors of the economy.
As a last resort, leave without pay with job protection is available in Ontario and other jurisdictions.

WHSC training can help

For our part, WHSC offers a range of training programs and resources to help workplace parties better understand the hazards placing the health of newborns at risk. Equally important, WHSC training and resources focus on measures to better protect pregnant workers and the health of newborns. This includes Hours of Work training and Ergonomics training scheduled for delivery in early 2024.

Employers are also required to ensure supervisors complete occupational health and safety awareness training and be competent to carry out their significant obligations to protect all workers. This training must be completed within one week of performing work as a supervisor. WHSC Supervisor Training can help workplaces comply.

Joint health and safety committees (JHSCs) and worker health and safety representatives (HSRs) in smaller workplaces also have a legal duty and right to participate in pursuit of safer, healthier work. To ensure JHSCs can effectively act on this right, employers must provide JHSCs in Ontario-regulated workplaces with training and many choose WHSC as their training partner for this. Many smaller workplaces choose to partner with the WHSC to ensure HSRs get the training they need.
Check out our complete in-person and virtual training schedule.

Want to know more?
Maternal Occupational Risk Factors and Preterm Birth: A Systematic Review and Metal-Analysis
Ergonomics can aid health pregnancies for women welders, study (WHSC)
Night work and long hours unhealthy for pregnant workers, says research (WHSC)
WHSC Shift Work hazard bulletin
WHSC Ergonomic resources

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