Pregnancy Permanently Changes Foot Size, Feet Are Wider and Longer According to Iowa Study

A new study shows the pregnancy can change your life in more ways that expected, and that includes the size of your feet.

A new University of Iowa study confirmed that pregnant women's feet permanently change size and shape throughout the nine-month period, according to Science Daily.

As flat feet are a common problem for pregnant women, the arch of the foot flattens out, possibly due to extra weight and increased looseness of the joints associated with pregnancy. The study, published in the March issue of the American Journal of Physical Medicine & Rehabilitation, suggests that this loss of arch height is, in fact, permanent.

"I had heard women reporting changes in their shoe size with pregnancy, but found nothing about that in medical journals or textbooks," says Neil Segal, M.D., UI associate professor of orthopaedics and rehabilitation.

 "In order to study this more scientifically, we measured women's feet at the beginning of their pregnancy and five months after delivery. We found that pregnancy does indeed lead to permanent changes in the feet."

The study followed 49 pregnant women and collected arch measurements during the first trimester and again about five months after childbirth. Researchers found that about 60 to 70 percent of women in the study had longer and wider feet.

Specifically, the study showed that, on average, arch height and measures of arch rigidity decreased significantly comparing early pregnancy with five months after childbirth, causing corresponding increases in foot length (between 2 and 10 mm) and arch drop.

However, no significant change in the distribution of foot pressure was detected. The study also suggested that first pregnancies may account for most of the observed changes, while second, third, or higher pregnancies may not further alter foot structure.