Advice needed

Ladies this is my first pregnancy where my hair is falling out in handfuls! Mind you this is my little girl and the other pregnancies were my boys. I don't know why this is hppening and I don't know what to do to stop it or at least just reduce the amount that is falling out. Does anyone have any advice they could share with me to help me from not going bald? At this rate with all my hair that is falling out I hope she has a full head of hair when she is born.