And you thought puberty was bad! When you become pregnant, your body will go through so many changes you’ll be left feeling like you were transported into a different body. Some of the strange bodily changes you’ll experience will go away. The extra curves, the thicker hair, and the pregnancy glow are a result of temporary hormonal changes. However, some changes will last forever. Unfortunately, your stretch marks are in that category, but we’ll save that painful discussion for another time. One surprising change you might notice is a bigger shoe size.
During pregnancy, your body produces large amounts of hormones that are meant to make the pregnancy and birthing process easier. One such hormone is known as relaxin. This hormone loosens the muscles and ligaments, which make your stomach’s expansion easier and will eventually make it easier for your baby to pass through your birth canal. Unfortunately, it doesn’t distinguish which muscles need to be loosened, so it affects all of them at once.
Now that you know what relaxin does, you’ll be able to imagine how it affects your feet during pregnancy. Since the arches of your feet are mainly made up of ligaments, the relaxin hormone will cause them to stretch out as you put weight on them. The bones in your foot will also adjust based on this expansion. After you’ve given birth, the relaxin will leave your body, but your feet will stay at their new, longer length.
Studies show that obese women will experience more of a stretch, so it is more likely your shoe size will change after pregnancy if you’re overweight. Similarly, women who spend a lot of time on their feet will suffer from a more increased shoe size.
Unfortunately, there is no telling how much the relaxin in your body during pregnancy will affect the size of your feet. However, you might be able to minimize it by achieving a healthy weight before pregnancy and spending as little time as possible standing. If your shoe size does go up, just think of it as the perfect excuse to buy more shoes.
– Yvonne S. Thornton, M. D., M. P. H.