Under normal circumstances, feet stop growing shortly after adolescence, according to the Maine Senior Guide. However, certain conditions, such as aging and pregnancy, can impact the size and shape of a person's feet well after that.
A woman may gain as much as a half-inch size in shoes during pregnancy, reports Maine Senior Guide. This increase is based on swelling and pressure from the weight of the pregnancy. The aging process affects the size of a person's foot. Later in life, the pressure placed by the body on weak foot muscles and ligaments causes stretching and thinning of fat pads on the bottom of the foot, according to the Los Angeles Times.