My Pregnant Feet: How Weight Gain and Other Body Changes Affect the Feet—and How to Cope
By Rachel Rader, DPM
Wound Care Specialist, Davis Regional Medical Center, Statesville, NC
IPFH Scientific Advisory Board Member
Pregnancy is such an exciting time in a woman's life! I’m happy to share that I've been pregnant three times and can't imagine my life without my beautiful children! That said, so much changes in a woman's body to help her carry her precious cargo—and many of those changes affect the feet. In a recent study of lower extremity changes during pregnancy, more than half of the women reported multiple effects on their feet, including faster toenail growth; roughened toenail texture; increased dry skin; foot swelling; hip, ankle and leg pain; unsteady gait; and increased foot width. (1) I experienced many of these issues myself!
The change that most affects a woman’s feet during pregnancy is weight gain. Institute of Medicine recommendations for weight gain during pregnancy range from 11 pounds to 40 pounds, depending on a woman’s pre-pregnancy body mass index (BMI). Of course, each pregnancy is different. I was able to stay within that range for my last pregnancy, but not for the first two, when I really exceeded the recommendations. My increased BMI definitely affected my feet, as it does for most pregnant women. Here are some of the common foot problems associated with that weight gain:
Flat feet/foot size. Also referred to as overpronation, flat feet occur when the feet roll inward during weight-bearing movements such as walking. The arches decrease in height and flatten out. Authors of a recent study on changes in arch height and other characteristics of the feet during pregnancy observed a small but significant decrease in arch height from the third to about the eight month of pregnancy, averaging about .04 inches, as well as pronated posture. (2) These characteristics produced increases in both foot length and forefoot width.
I personally went from a size 7-½ shoe to a size 9, and I’ve remained there since my first pregnancy eight years ago. Experts believe the first pregnancy may account for most of the changes in arch height, so subsequent pregnancies may not further affect foot structure.
However, changes in BMI can have an effect. Researchers in Taiwan found that BMI changes over the course of pregnancy could actually predict changes in foot size. (3) From the fifth to the final month of pregnancy, the feet of the women in the study group increased an average of 3.6% in length, 2.6% in width and 11.9% in rear foot surface area—and arch height decreased an average of 24.2%. Not surprisingly, those women also complained that their shoes were too tight, resulting in foot discomfort.
Researchers from Texas Tech University Health Sciences Center studied two groups of women—one group had never been pregnant and the other had been pregnant at least 10 years prior to the study. They found that in women who had been pregnant and also had been classified as obese based on BMI, the combination of pregnancy and obesity resulted in collapsed arches over time. (4) I concur with these findings and, sadly, had to donate quite a few pairs of shoes from my roaring twenties that I could no longer fit into. I’ve made peace with the tradeoff for some adorable pink and blue booties—and that’s a good thing, because a recent study by University of Iowa researchers found that the arch height reduction and flattening of the feet that happen during pregnancy seem to be permanent. (5)