Over the years, I’ve had many women ask me why their hair appears to have become thinner after having a baby. It’s common knowledge that hair often become considerably thicker during pregnancy, but women are less prepared for their hair loss after giving birth.
During pregnancy there is over production of female hormone oestrogen. This results in the hairs spending more time in the growing and resting phases of the hair cycle, and less in the shedding phase. We lose, on average, 100 hairs a day, but, as a result of shorter shedding cycles, pregnant women lose far fewer. The hair often appears thicker because of this.
After childbirth, a woman’s oestrogen levels plummet. As a result, the hair spends less time in the growing phase, and more hairs than normal will now enter the shedding phase.
The drop in oestrogen levels, and subsequent increase in the number of hairs in the shedding phase means that in some women, hair will appear thinner than it was pre-pregnancy.
Within a few months of giving birth, oestrogen levels will return to normal. Because of this, the hair growth cycles balance out, and within a few months, a woman’s hair will return to its pre-pregnancy thickness.