Michael Harper for redOrbit.com — Your Universe Online
As it turns out, having one human person growing inside another human person can have some dramatic effects. From generation to generation, women have shared their experiences with one another to share some of the burden or offer advice. One common side effect experienced by many pregnant women is a shoe size that grows along with their tummies. Though this phenomenon has long been observed (and long been explained), one doctor has performed some scientific studies to prove why pregnant women´s feet grow once and for all.
The results of this study have been published in the American Journal of Physical Medicine & Rehabilitation. Along with proving why these feet grow, Dr. Neil Segal, University of Iowa associate professor of orthopedics and rehabilitation, also discovered this change could also explain why women are prone to musculoskeletal disorders.
“I had heard women reporting changes in their shoe size with pregnancy, but found nothing about that in medical journals or textbooks,” said Dr. Segal in a press statement.
“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 method used to study this effect is simple and straightforward. Dr. Segal took measurements of the pregnant women´s feet in their first trimester. Then, five months after they gave birth, he measured their foot again and compared the differences. Of the 49 women who participated in this foot study, 60 to 70 percent saw their feet get wider and longer as a result of the pregnancy.
First-time mothers saw the most significant changes to their shoe size, but any subsequent pregnancies may or may not continue to change their size and shape of the foot. This foot structure, says Dr. Segal, could lead to other problems in the body.
“We know that women, and especially women who have had children, are disproportionately affected by musculoskeletal disorders,” said Dr. Segal.
“It is possible that these foot changes that occur during pregnancy may help explain why, in comparison with men, women are at higher risk for pain or arthritis in their feet, knees, hips, and spines.”
This study doesn´t so much explain this phenomenon as it recognizes it.
In a 2010 article, podiatrist Jane Andersen explains this matter of the growing foot, saying the extra weight carried around during pregnancy is partially responsible for a widening foot. The other player is a hormone, which is aptly named “relaxin.” This hormone loosens the joints around the pelvic area so the baby will be able to make its way out. Relaxin also works on other joints and ligaments as well, specifically the ligaments in the feet.
As these ligaments become less rigid, the extra weight of pregnancy causes the bones to shift and spread apart. Though Dr. Segal notes growing feet may not accompany second, third and fourth pregnancies, Andersen claims a woman´s foot can continue to grow along with every subsequent pregnancy.