Excessive forward bending and prolonged walking during early pregnancy may elevate the risk of miscarriage, according to recent research.
Miscarriage occurs in roughly 15% of pregnancies, with risk heightened by factors such as advanced parental age, smoking, night‑shift work, and exposure to air pollutants and certain chemicals.
Although earlier studies have hinted that forward bending, walking, and prolonged standing at work could increase miscarriage risk, results have been inconsistent. To clarify this, investigators examined pregnancy outcomes of nearly half a million Danish women.
Each additional hour of forward bending—especially at a 30‑degree angle—within an eight‑hour workday correlated with a 36% rise in miscarriage risk, while each extra hour of walking increased risk by 18%.
The analysis, encompassing 803,829 pregnancies from 475,312 women between 2004 and 2018, appeared in Occupational and Environmental Medicine.
Researchers from Bispebjerg Hospital and the University of Copenhagen employed an enhanced, pregnancy‑specific job exposure model that integrated activity‑tracker data with expert assessment of time spent standing, walking, and forward bending at angles of 30 degrees or greater.
Approximately one in ten pregnancies (81,307 cases) resulted in miscarriage, slightly below the typical rate. The data indicated that forward bending, walking, and standing were each linked to a higher miscarriage risk.
Every extra hour of forward bending at a 30‑degree angle corresponded to a 36% increase in risk, whereas an additional hour of walking or standing raised risk by 18% and 3%, respectively.
As an observational study, it does not establish causality. Additional limitations include the absence of individual smoking data during pregnancy.
Further research incorporating other relevant factors is required to validate these results, underscoring the need to incorporate early pregnancy considerations into workplace guidelines for pregnant employees, the authors assert.
The authors noted that, although the underlying mechanisms remain unclear, occupational exposures may impair placental perfusion or hormonal regulation, potentially raising miscarriage risk.
Prof Asma Khalil, professor of obstetrics and maternal medicine and consultant obstetrician at City St George’s, University of London, who was not involved in the study, cautioned that these findings should not be taken to imply that normal early‑pregnancy movement is unsafe.
This robust, nationwide register‑based cohort study, which analyzed Danish data from over 800,000 pregnancies, is a major strength; its use of a pregnancy‑specific job exposure matrix to estimate occupational standing, walking, and forward bending reduces recall bias compared with self‑reporting.
The primary finding indicates that forward bending at work is linked to a higher miscarriage risk, showing a clearer dose‑response relationship than for standing or walking, though, as an observational study, it cannot establish causality.
Key limitations comprise the lack of individual smoking data, inability to adjust for lifting activities, and potential confounding from other occupational factors such as shift work or chemical exposures, Khalil added.
The study proposes a hypothesis linking occupational postures to miscarriage risk, but replication in diverse populations is required before these findings can inform precise workplace guidance.