Pregnancy might change the size of a woman’s foot permanently. A University of Iowa study examined 49 pregnant women and found that about 60% of them had their feet become wider and longer. It is thought that this might be the result of the hormone relaxin, which helps the pelvis become more flexible in preparation for birth. Relaxin might also affect other ligaments and joints, such as those in the foot. This flexibility, combined with the additional weight of pregnancy, might cause the arch of the foot to become flattened.
More about how pregnancy affects the foot:
Women who have given birth and had their feet permanently changed are more likely to suffer arthritis and pain in the foot, as well as in the hips, knees and spine, as they age.
The majority of changes to the foot tend to occur during a woman’s first pregnancy, but multiple pregnancies could worsen the condition.
The University of Iowa study found that the average increase in foot length was about 0.1-0.4 inches (about 2-10 mm) when measured five months after delivery.