When I was pregnant, I was teaching a class at a local college. I found it very difficult to do a lot of standing just because I was tired and the extra weight of the pregnancy made my feet hurt. However, there may be other good reasons not to stand too much during pregnancy.
If you have a job which requires long hours standing, you may want to modify your work situation, especially in the 3rd trimester. Standing for long periods at this time may affect fetal growth:
But during the third trimester of pregnancy, they found that long periods of standing were signiﬁcantly associated with a 3 percent smaller head circumference in infants. In addition, working more than 40 hours a week was associated with a smaller head circumference and lower fetal growth. Long working hours were associated with approximately a 5 to 7 ounce lower birth weight.
“This effect seems to be of similar magnitude than the effects of other well-known lifestyle factors, such as smoking and caffeine intake,” the authors wrote.