Bending forwards at work in early pregnancy linked to 36% higher miscarriage risk, study finds

Bending forwards for just one extra hour in an eight-hour working day during early pregnancy is associated with a 36% higher risk of miscarriage, according to a major Danish study involving nearly half a million women. The research, published in the journal Occupational and Environmental Medicine, also found that each additional hour of walking was linked to an 18% higher risk, while standing raised the risk by 3%. Drawing on data from 803,829 pregnancies among 475,312 women between 2004 and 2018, researchers from Bispebjerg hospital in Copenhagen and the University of Copenhagen used activity tracker readings and expert evaluations to create a pregnancy-specific job exposure model. About one in ten pregnancies – 81,307 – ended in miscarriage, a figure lower than the typical prevalence of around 15% of women. The analysis showed that forward bending, particularly at a 30-degree angle, was associated with the highest risk increase. However, the study was observational, meaning no firm conclusions about cause and effect can be drawn, and it lacked individual data on smoking during pregnancy, which is a known risk factor. “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,” the researchers said. Other known risk factors include parental age, smoking, night shift work, and exposure to air pollution and chemical compounds. The authors stressed that further studies including potentially influential factors are needed to confirm the findings, but they highlighted the importance of including the early stages of pregnancy in guidelines for pregnant workers.