What causes loss of hairline during breastfeeding?

Hair loss during breastfeeding is caused by a drop in estrogen levels. Estrogen is a hormone produced by the ovaries that helps to keep hair in the growth phase. When estrogen levels drop, hair can enter the shedding phase and fall out. This type of hair loss is called postpartum hair loss and it usually starts 2-4 months after giving birth. It can last for several months but it usually resolves on its own.