Many expectant mothers notice their shoes no longer fit, leading to the question of whether feet grow during pregnancy. A change in foot size or shape is a frequent physiological event caused by hormonal and mechanical factors. This transformation is not bone growth, but rather a change in the feet’s structure and volume that affects footwear fit. Understanding the science helps distinguish temporary discomfort from potentially permanent alterations.
The Role of Relaxin and Increased Body Weight
The primary factor driving structural changes in the feet is the surge of the hormone relaxin, produced early in pregnancy. While its main function is to loosen pelvic ligaments for childbirth, relaxin affects ligaments throughout the entire body, including the feet. This hormonal effect causes connective tissues to become more pliable.
This increased ligament laxity softens the structures holding the foot’s arch. As pregnancy progresses, the increase in body weight places a greater load on these softened arches. The combination of relaxed ligaments and sustained pressure causes the arch to flatten, known as over-pronation. This flattening lengthens and widens the foot as the bones spread out.
Differentiating Temporary Swelling from Permanent Change
Increased foot size stems from two main causes: temporary swelling and potentially long-lasting structural change. Temporary swelling, medically termed edema, is common, affecting about three-quarters of pregnant women, particularly in later stages. Edema occurs because the body retains more fluid and the growing uterus slows circulation in the lower limbs.
Edema increases volume around the ankles and feet, making shoes feel tight, and is often worse at the end of the day or in hot weather. This fluid retention is temporary and generally subsides within a month after delivery as fluid levels return to normal. The potentially permanent change is the structural lengthening and widening caused by arch flattening from ligament laxity and weight gain. Studies suggest that 60 to 70 percent of women experience longer and wider feet five months after delivery, with the change most pronounced after a first pregnancy.
Practical Steps and Long-Term Foot Health
Supportive footwear is advised throughout pregnancy to manage discomfort caused by swelling and arch changes. Shoes should offer good arch support and cushioning, and have a wider toe box to accommodate swelling. Avoiding shoes with little support, such as flip-flops or high heels, is recommended due to increased ligament flexibility and potential for instability.
To reduce edema, simple measures include:
- Elevating the feet above heart level whenever possible.
- Staying active with low-impact exercises such as walking or swimming, which improve circulation.
- Wearing compression stockings, which help prevent fluid from pooling in the lower extremities.
If arch pain persists after temporary swelling resolves, custom or over-the-counter orthotic inserts can provide better support to the flattened arches. The permanent change in foot length is typically modest, often amounting to a half to one full shoe size. The long-term goal is to maintain comfort and stability to prevent future foot and joint issues.