Certain actions in early pregnancy may raise risk of miscarriage, large-scale study finds

CTV medical specialist Dr. Marla Shapiro says 15 per cent of pregnancies can result in miscarriage, and the emotional impact is understated.

The more women walk, bend forward, or stand in early pregnancy, the greater their risk of miscarriage may be, according to a new large-scale study.

The study indicated the risk for miscarriage was 36 per cent higher for each extra hour of bending forwards, especially at a 30-degree angle. Each additional hour of walking was connected to an 18 per cent higher risk, and for standing, the risk was three per cent higher.

The study examined women’s actions within the first four months of pregnancy.

“Although the mechanisms are not completely understood, these occupational exposures may affect placental perfusion or hormonal regulation in ways that could increase the risk of miscarriage,” according to the study published Thursday in the Occupational & Environmental Medicine, an international peer reviewed journal.

The findings are based on national register data on the pregnancies of working women living in Denmark between 2004 and 2018. They involved 803,829 pregnancies among 475,312 women.

The findings raise concerns about occupational physical activity, referring to the movements and energy in performing a job, during pregnancy.

Other risk factors for miscarriages include smoking, night shift work, the age of the parent at the time of delivery, and exposure to air pollution and chemical compounds, according to the Occupational & Environmental Medicine study.

Researchers said “no firm conclusions can be drawn about cause and effect” because it was an observational study.

The overall impact of bending forward for a long time is probably limited because the action is uncommon at the workplace, they added.

The study found that more than one-in-10 (or 81,307) of the total pregnancies ended in miscarriage. The figure is lower than normal, according to researchers, potentially because many early miscarriages are handled at home and not registered in hospital data.

Researchers said the findings underscore the need to include the early pregnancy stage into guidelines for pregnant workers. They noted the lack of formal guidelines on forward bending and on occupational standing or walking within the first four months of pregnancy, and no guidance on forward bending in Denmark.