Danish research links workplace bending, walking and standing with higher miscarriage risk

Bending forward and walking frequently at work during early pregnancy may increase the risk of miscarriage, according to a large Danish study.

Researchers analysed data from 803,829 pregnancies among 475,312 women in Denmark between 2004 and 2018 to examine whether certain workplace movements were linked to pregnancy loss.

The findings, published in the journal Occupational and Environmental Medicine, suggest that forward bending, walking and standing at work were all associated with a higher risk of miscarriage.

Miscarriage affects around 15% of women. Known risk factors include parental age, smoking, night shift work, air pollution and exposure to some chemical compounds.

Previous studies have suggested that certain physical demands at work may also play a role, but the evidence has been unclear.

To investigate the issue further, researchers from Bispebjerg Hospital in Copenhagen and the University of Copenhagen used a pregnancy-specific job exposure model. This combined activity tracker readings with expert evaluations to estimate time spent standing, walking and bending forwards at an angle of 30 degrees or more.

The study found that each additional hour of forward bending during an eight-hour working day was associated with a 36% higher risk of miscarriage.

Every extra hour of walking was linked to an 18% higher risk, while each additional hour of standing was associated with a 3% higher risk.

Out of the pregnancies included in the study, 81,307 ended in miscarriage.

Researchers said the findings highlight the importance of considering the early stages of pregnancy when developing workplace guidance for pregnant employees.

They suggested that these occupational exposures may affect placental blood flow or hormonal regulation in ways that could increase miscarriage risk, although the exact biological mechanisms remain unclear.

However, experts cautioned that the research does not prove that workplace bending, walking or standing directly causes miscarriage.

The study was observational, meaning it can identify associations but cannot confirm cause and effect.

There were also several limitations. Researchers did not have individual data on smoking during pregnancy, and they were unable to adjust fully for lifting or other possible workplace factors such as shift work or chemical exposure.

Professor Asma Khalil, professor of obstetrics and maternal medicine and consultant obstetrician at City St George’s, University of London, said the findings should not be interpreted as meaning ordinary movement during early pregnancy is unsafe.

She described the research as a large and well-conducted nationwide study, but emphasised that it could not prove causation.

Khalil noted that the most consistent association was seen with forward bending, while the links with walking and standing were less clear.

She added that the findings would need to be repeated and confirmed in other populations before they could be turned into specific workplace guidance.

The study raises fresh questions about how employers should support pregnant workers, particularly those in physically demanding jobs.

It may also increase calls for more careful risk assessments during the earliest stages of pregnancy, when many workers may not yet have formally disclosed that they are pregnant.

For now, the findings suggest that workplace posture and physical activity could be important areas for further research.

Experts continue to stress that pregnant people should not panic or stop normal daily movement based on this study alone.

Anyone concerned about their work duties during pregnancy should seek advice from a healthcare professional or occupational health service.

The research adds to growing evidence that workplace conditions may influence pregnancy outcomes, but scientists say more studies are needed before clear conclusions can be made.