Is prolonged standing at work safe during pregnancy?

What does the evidence say about prolonged standing at work during pregnancy?

1. Pooled across studies, standing more than four hours a day at work was associated with a relative risk of 1.22 for preterm delivery, and no meaningful increase in small-for-gestational-age birth (relative risk 1.07, confidence interval crossing 1). 1
2. A 2023 systematic review rated the evidence linking prolonged standing to preterm birth as very low, finding no statistically significant association once exposure definitions were compared across studies. 2
3. Among nurses, standing or walking nine or more hours a day was only weakly linked to preterm birth (relative risk 1.2, confidence interval touching 1), while working part time at 20 hours a week or less was associated with lower risk. 3
4. In the Southampton Women's Survey, standing or walking more than four hours a day showed no statistically significant association with preterm delivery or a small-for-gestational-age baby, though bending the trunk more than an hour a day was linked to preterm delivery at 34 weeks. 4
5. Long hours carry a clearer signal than standing does: working more than 40 hours a week was associated with a relative risk of 1.23 for preterm delivery in pooled analysis, and an odds ratio of 1.44 in a later review rated as moderate evidence. 2

Is prolonged standing at work safe in each trimester?

• First trimester. Standing still makes first-trimester dizziness worse, because blood pools in your legs when the calf muscles are not moving. Shift your weight, walk a few steps every so often, and eat regularly through the shift.
• Second trimester. This is the easiest stretch to standardise a routine: a stool for tasks that do not need standing, a cushioned mat where you stand most, and shoes that support rather than flatter.
• Third trimester. Swelling and back pain peak now and prolonged standing drives both. Elevating your feet on breaks and putting compression stockings on before you leave the house make a bigger difference than anything you do at the end of the day.