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Standing for too long while pregnant may slow a baby's growth

Standing for long periods of time while pregnant may stunt the growth of a developing baby, research suggests.

Yet working up until the 36th week of pregnancy is reported to have “no adverse effect” on the fetus.

A study published in Occupational and Environmental Medicine assessed the fetal growth rates of 4680 mothers-to-be over a four-year period from 2002 to 2006.

Around four out of 10 (38.5%) of the women being analysed said they spent a long time on their feet and 45.5% had to walk for long periods. Heavy lifting was part of the job for just 6%, while around 4% worked night shifts.

The development of their babies was regularly measured throughout pregnancy using ultrasound, and then again at birth.

Study findings showed that physically demanding work and long working hours were not “consistently associated” with any restrictions on the overall size or birthweight of a baby or with premature birth.

Yet, women who worked more than 40 hours a week were found to give birth to babies between 148 and 198g smaller than those who worked under 25 hours a week. 

Furthermore, those women who spent long periods on their feet during their pregnancy, in jobs such as sales, childcare, and teaching, had babies whose heads were an average of 1 cm (3%) smaller than average at birth, implying a slower growth rate.

“Generally women who are in work have fewer pregnancy complications, birth defects, and stillbirths than women who are unemployed, but certain aspects of work may not be without risk,” said the authors.