A new study suggests that bending forward frequently at work during early pregnancy may increase the risk of miscarriage. The research, which analyzed data from nearly half a million pregnancies in Denmark, found that each additional hour of forward bending in an eight-hour workday was associated with a 36% higher risk of miscarriage. Walking and standing at work were also linked to increased risk, though to a lesser extent.
Study Details
The study, published in the journal Occupational and Environmental Medicine, examined 803,829 pregnancies among 475,312 women between 2004 and 2018. About one in ten pregnancies (81,307) ended in miscarriage. Researchers from Bispebjerg Hospital and the University of Copenhagen used a pregnancy-specific job exposure model that combined activity tracker data and expert evaluations of time spent standing, walking, and bending forward at a 30-degree angle or more.
Key Findings
- Each additional hour of forward bending at a 30-degree angle was associated with a 36% higher miscarriage risk.
- Each additional hour of walking was linked to an 18% higher risk.
- Each additional hour of standing was associated with a 3% higher risk.
Limitations and Expert Commentary
The study is observational, meaning it cannot establish cause and effect. Limitations include the lack of individual data on smoking during pregnancy and potential confounding factors such as lifting or shift work. Prof. Asma Khalil from City St George's, University of London, noted that the findings should not be interpreted as ordinary movement in early pregnancy being unsafe, and that further research is needed before precise workplace guidelines can be developed.
Implications
Researchers emphasized the importance of including early pregnancy in guidelines for pregnant workers. They suggested that occupational exposures may affect placental perfusion or hormonal regulation, potentially increasing miscarriage risk, though the mechanisms are not fully understood.
