Hair and Nails
Normal human hair growth occurs through a repeated cycle of stages: growth (anagen), stoppage of growth (catagen), resting stage (telogen), and shedding (exogen). These phases can be influenced by different physiological and hormonal factors throughout life.
At any moment, a follicle is either growing, ceasing to grow, regressing but still on the scalp, shedding, or entering a new cycle. The duration of each cycle is variable but typically ranges from a few weeks to several years.
During pregnancy, hormonal changes can affect how the hair grows, looks, and feels as early as 15 weeks of pregnancy.
Researchers previously believed hair growth increased during pregnancy, but it is now assessed that rather than additional hair growth, the apparent increase in hair strands is more likely due to a delayed shedding and an increase in strand diameter.
Therefore, many women may experience a thicker, fuller texture, and hair strands already on the scalp may grow faster.
Other women may experience hair that becomes limp, lifeless, or notice more hair falling out, as women can respond differently to hormones.
True extra hair growth can occur, however, on other parts of the body, such as the abdomen, upper lip, cheeks, jaw lines, arms, legs, or back, and is considered normal during pregnancy.
Above normal excessive hair growth during pregnancy could be related to polycystic ovarian syndrome or other underlying medical conditions. It is recommended that women who believe they may be experiencing excessive hair growth should talk to their HCP.
Women's hair cycles return to normal after pregnancy, beginning around two to four months postpartum.
During this process, individual hair cycles simultaneously become coordinated again, and hairs that were previously in various phases begin shedding (due to a fall in estrogen).
This can be quick in some women; hairs can begin falling out within a few days of coordination. This sudden hair loss can cause some women to panic, but is considered normal.
Note: Women with longer hair can have a misperception of a larger amount of hair falling out, but this is likely due to longer hair strands clumped together.
Women should remember this is not true hair loss, but loss of the extra hair women retained during pregnancy which is estimated to be about 10% of all hairs on the scalp. Hair loss may be most evident around the hairline of the forehead.
Hair may also shed gradually for about 6 to 24 weeks but rarely continues past a year.
Extra hair on other parts of the body will also shed, especially if they were soft or fine. If the extra hair was a bit coarser, it could last a bit longer or remain permanent.
Women with an unusual amount of hair loss during pregnancy could be experiencing vitamin or mineral deficiencies and should talk to their HCP.
*New mothers should watch out for hair tourniquets. A hair tourniquet forms when a strand of hair falls out and wraps around a baby’s toe, finger, or other body part. A single strand can wrap so tightly that it cuts off circulation or causes an infection*.
A limited number of studies have been conducted on the effect of pregnancy on the nails:
Some studies report that nail alterations occur in 2% to 40% of pregnant women.
Common nail changes can include white spots, ingrown toenails, and splitting of the nail. Separation of the nail from the nail bed (painless) and brittle nails are also frequently reported.
Overall, rapid nail growth is not observed very often. However, some women may experience faster nail growth especially in the last months of pregnancy, but this may also make them brittle and soft.
Further, the irregular production of keratin during pregnancy causes nail ridges – horizontal lines or furrows running across the width of the nail.
Hyperpigmentation of multiple nails can also occur during pregnancy with fading that occurs after delivery.
Pregnant women who have any questions or concerns related to their hair or nail growth should talk to their HCP.
Women should also note that although biotin is commonly promoted for the health and growth of skin, hair, and nails, supplementation during pregnancy is not recommended. Women should always talk to their HCP before taking any supplements.
Women can read more information on the safety of hair dye here.