You might want to take breaks every now and then if you're standing a lot during pregnancy. A new study, published online in Occupational and Environmental Medicine, found that women who spent long amounts of time on their feet at work during pregnancy had babies whose heads were 1 centimeter smaller and weights were 148 and 198 grams smaller than average at birth. Researchers looked at the growth of fetuses in 4,680 moms between 2002 and 2006. The women were asked about their working conditions in the middle of their pregnancies. Their babies were routinely measured during their pregnancy and after birth.
Half the women who stood a lot in their jobs worked 25-39 hours a week, while one in four worked more than 40 hours a week. Of those women, the ones who worked more than 40 hours a week had smaller babies.
While standing for long periods of time seemed to have affected the babies, long working hours and physically demanding work did not. The researchers also found that there were no negative effects to working until 36 weeks pregnant. Of course, if women work long hours and do a lot of heavy lifting or moving, they should take frequent breaks and move around. If you're sitting too much, get up and walk around. If you're standing, make sure to sit down once in a while.