Leaning forward during early pregnancy and, to a lesser extent, walking a lot at work, may increase the risk of miscarriage, a large study of more than 470,000 Danish women found, published online in an academic journal. Occupational and environmental medicine.
Specifically, they found that each additional hour of time spent bending over at a 30-degree angle was associated with a 36% increased risk, and each additional hour of walking was associated with an 18% increased risk, but this pattern was consistent only for stooping, the study found.
Miscarriages are relatively common, affecting approximately 15% of women. Risk factors include parental age, smoking, night shifts, and exposure to air pollution and various compounds, the researchers said.
There is some evidence to suggest that standing, walking, and bending over at work may also increase risk, but the results are not conclusive. And given that almost 70% of women in Europe work, concerns have been raised about safe levels of occupational physical activity during pregnancy, they added.
To investigate this further, the researchers used data from a large national registry containing information on pregnancies among working women living in Denmark from 1977 to 2018.
They focused on 475,312 women who had 803,829 pregnancies between January 2004 and December 2018.
Researchers introduced an improved pregnancy-specific occupational exposure model that combined activity tracker measurements with expert ratings of time spent standing, walking, and bending over at an angle of 30 degrees or more.
Just over one in 10 pregnancies (81,307) ended in miscarriage, which is lower than normal prevalence rates, the researchers said, possibly because the data came from hospital registries and many early miscarriages were handled at home and not registered in hospital data.
When they analyzed the results, they found that standing, walking, and bending forward were all associated with an increased risk of miscarriage.
Specifically, an additional hour of forward bending at a 30-degree angle increased the risk by 36%, and an additional hour of walking and standing increased the risk by 18% and 3%, respectively.
The risk was greater for women who had missed work in the previous week than for women who had not been absent.
Further analysis showed a consistent dose-response relationship only for forward bending.
Because this is an observational study, no clear conclusions can be drawn about cause and effect. And although the researchers acknowledged that they had no individual-level information on smoking during pregnancy and could not account for smoking cessation, it may partially explain the observed association, as well as shift work and chemical exposure.
And because prolonged forward bending is relatively rare in most jobs, the researchers suggest that despite the higher risk estimates, its overall impact is likely to be limited.
Further studies incorporating potentially influencing factors are needed to confirm the results, they stress.
Nevertheless, the researchers suggest that “although the mechanisms are not fully understood, these occupational exposures may affect placental perfusion and hormonal regulation, increasing the risk of miscarriage.”
They added: “In Denmark, there are currently no formal guidelines for occupational standing and walking during the first four months of pregnancy, and no guidance regarding forward bending.
“Our findings highlight the importance of including the early stages of pregnancy in guidelines for pregnant workers.”
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Reference magazines:
Frankel, Hannah State; others. (2026). Occupational standing, walking, and forward bending during pregnancy and risk of miscarriage: A Danish national register-based cohort study. Occupational and environmental medicine. DOI: 10.1136/oemed-2025-110712. https://oem.bmj.com/content/early/2026/06/14/oemed-2025-110712
