How come my feet changed a size in pregnancy?

Ligament laxity. With pregnancy, hormones produced help allow the ligaments to stretch to allow for delivery of the baby. This hormone can affect other ligament, such as those that connect and support the bones in the foot. With each pregnancy, it is not unusual for the foot to lengthen 1/2 size. Measure your feet before purchasing shoes. Over time, most all(men and women) have an increase in foot length. Dr l.