New parents may be surprised to notice their newborn’s hair suddenly thinning or falling out, sometimes leaving bald patches. This common occurrence, often called neonatal alopecia, is a normal and temporary part of a baby’s adjustment to life outside the womb. Finding loose strands is typically not a sign of an underlying health concern, but rather a predictable event most infants experience within their first six months of life.
The Physiology Behind Normal Shedding
The primary reason for widespread hair loss in newborns is a natural shift in the hair growth cycle, a phenomenon known as telogen effluvium. Hair follicles cycle through growth (anagen), transitional (catagen), and resting (telogen) phases. While in the womb, high levels of maternal hormones, such as estrogen, influence the baby’s hair to remain predominantly in the growth phase.
After birth, the sudden drop in hormone exposure signals a large number of hair follicles to simultaneously enter the telogen (resting) phase. This synchronized resting period causes the hair to detach and shed about two to three months later, which is when shedding often peaks. This mechanism is similar to the postpartum hair loss many mothers experience.
Another common cause of localized hair loss is friction alopecia, which typically results in a bald spot on the back of the head. Since infants spend significant time lying on their backs for safe sleep, constant rubbing against the mattress, car seat, or play mat causes delicate hair strands to break off. This mechanical breakage is common between three and six months of age when babies begin to turn and rub their heads more frequently. Hair lost due to friction is not a medical issue but a physical reaction to contact with a firm surface.
Recognizing When Hair Loss Is Not Normal
While most hair loss is natural, specific signs may suggest an underlying medical condition requiring a pediatrician visit. One concern is tinea capitis, a fungal infection of the scalp often called ringworm. Unlike normal shedding, tinea capitis usually presents with patchy hair loss accompanied by inflammation, redness, or scaly patches.
The affected areas may also show small pustules or tiny black dots, which are remnants of broken-off hair shafts. Hair loss that is unevenly distributed and appears in smooth, bald, circular patches may point to alopecia areata, an autoimmune condition. If hair loss persists beyond six months, or is associated with symptoms like poor growth or developmental delays, a medical evaluation is recommended to rule out rare issues such as thyroid problems or nutritional deficiencies.
The Timeline for New Hair Growth
Parents can expect new hair to begin growing back shortly after the initial shedding phase is complete, though the timeline varies significantly. For most infants, permanent hair growth begins between three and seven months of age. It can take until the baby’s first birthday for a full head of hair to return, and sometimes up to two or three years to achieve its final thickness and length.
The replacement hair often differs noticeably from the fine, downy hair (lanugo or vellus hair) the baby was born with. Parents are often surprised to find the new strands may have a different color, texture, or thickness. For example, dark, straight newborn hair might be replaced with hair that is lighter and curly, or fine hair might come back much thicker. These changes occur because the baby’s own genetics and hormones are now determining the hair’s characteristics.
Gentle Care and Management Practices
No specific medical treatment is necessary for normal, hormone-related hair loss, as the hair regrows on its own. Parents can take steps to minimize friction-related bald spots and protect the delicate new hair. Encouraging supervised tummy time helps relieve pressure on the back of the head. When placing the baby down to sleep, alternating the direction they face in the crib helps distribute pressure more evenly across the scalp.
When washing the hair, use a gentle, tearless baby shampoo only a few times a week to avoid drying out the scalp. Use a soft-bristle brush or wide-toothed comb to gently manage the hair, avoiding excessive scrubbing or tight hairstyles that can cause breakage. If you notice cradle cap, treating this common scaly patch condition gently with a mild shampoo and soft brushing can prevent hair from coming out when the scales detach.