Among the most commonly noted observations during pregnancy is a perceived change in the condition and growth rate of fingernails and toenails. Many pregnant individuals report needing to trim their nails much more frequently than before. This common experience prompts an investigation into the biological reality of nail growth during gestation.
The Observed Changes in Nail Growth During Pregnancy
Studies show that a significant percentage of pregnant women, around 34%, report experiencing changes in their nails, which is a much higher rate than in non-pregnant women. While some rigorous measurements have shown no statistically significant change in the linear rate of growth, the perception of acceleration is often due to an observed increase in nail thickness.
This increase in thickness can make the nail plate feel stronger and more resilient, contributing to the idea of “faster” or “healthier” growth. However, hormonal shifts can also lead to other structural changes, such as brittleness and splitting (onychoschizia), which tends to occur more frequently in the later stages of pregnancy. White spots on the nail plate, called leukonychia, are also a common and harmless finding during this time, reported in approximately 24% of pregnant women.
Physiological Mechanisms Behind Accelerated Nail Growth
The underlying biology for these changes centers on hormonal and circulatory adjustments that occur during gestation. The body experiences a surge in hormones, particularly estrogen and progesterone, which are known to stimulate cell division and proliferation. The nail plate is formed by keratin production in the nail matrix, and this hormonal stimulation can increase the activity of those cells.
Beyond the direct hormonal influence, the increased blood volume in the body during pregnancy plays a substantial role. A woman’s blood volume can increase by up to 50% by the third trimester to support the developing fetus. This enhanced peripheral circulation ensures a greater supply of oxygen and nutrients is delivered to the nail matrix, which is the source of nail growth. This richer supply of building blocks and energy fuels the production of keratin, leading to the increased thickness and the commonly perceived acceleration of growth.
Postpartum Reversal of Nail Growth Rates
The changes experienced during pregnancy are temporary, and the nail growth cycle begins to reverse after childbirth. The delivery of the placenta causes a drop in the levels of estrogen and progesterone, which eliminates the primary stimulant for the accelerated growth and increased thickness. As the body’s hormonal profile shifts back toward pre-pregnancy levels, the growth rate of the nails slows down.
This deceleration often leads to a period where the nails feel more fragile, brittle, or prone to breaking. The weaker, slower-growing nail tissue begins to replace the sturdy, fast-growing tissue that developed during pregnancy. This transition can result in noticeable splitting or peeling, which is a common complaint in the months following delivery. Since fingernails take approximately three to six months to fully replace themselves, this period of postpartum brittleness typically resolves.