Pregnancy and childbirth greatly alter the levels of hormones in the body. These changes in hormones can in turn trigger changes in hair growth.
During pregnancy, your hair will remain in the growth or transitional stages, so it becomes much thicker with hair that would normally have stopped growing or fall out. About three months following delivery, your hair will resume falling out, and all the hair that would have fallen out during your pregnancy may fall out quite suddenly. Rest assured that this is normal and temporary and that this rate of hair loss will not continue. Take care of your hair and treat it gently while you wait for your normal hair growth to return.