What is the Origin of Postpartum Hair Loss?

The term combines "postpartum," meaning following childbirth, and "hair loss," the observable clinical symptom. This phenomenon has been recognized anecdotally for centuries, but its physiological basis was formally understood with the development of modern trichology and endocrinology. The identification of its mechanism as telogen effluvium links the clinical observation directly to the hair growth cycle and the influence of pregnancy hormones.

What is the Mechanism of Postpartum Hair Loss?

The primary mechanism is the rapid withdrawal of high levels of estrogen and progesterone following delivery of the placenta. During pregnancy, these elevated hormones prolong the hair's anagen phase, leading to a thicker head of hair. Once hormone levels plummet after birth, the synchronized follicles abruptly enter the catagen (transition) and then the telogen (resting) phase. Approximately two to four months later, the resting hairs are shed en masse, leading to the noticeable hair loss, which typically self-resolves as the hair cycle stabilizes.

Postpartum Hair Loss

Meaning

Postpartum hair loss, clinically known as telogen effluvium, is a common, temporary condition characterized by excessive hair shedding that typically begins one to five months after childbirth. This physiological event is not a true pathological hair loss but rather a sudden shift of a large number of hair follicles from the growing phase (anagen) into the resting phase (telogen). It is a direct, delayed consequence of the dramatic hormonal fluctuations experienced during the peripartum period.