After childbirth, levels of oestrogen and other hormones drop rapidly to pre-pregnancy levels. In addition, cortisol levels remain high and in some women thyroid hormones may become unbalanced. This creates a rapid synchronous transition of follicles from their growth phase to a resting phase.
This, combined with lack of sleep, nutritional stress and the demands required to care for a newborn, is conducive to hair loss. When follicles enter the resting phase, they begin to shed after 3 to 4 months. Early implementation of some preventive measures can help reduce the severity of the problem.