Pregnancy causes a variety of hormonal changes for women both during the pregnancy phase and after. The extra hormones produced during pregnancy can affect hair in many different ways. About a third of women report their hair feeling healthier and thicker in the midst of their pregnancy. Some women, on the other hand, feel their hair is drier and more problematic than usual. Hormonal changes vary in each individual and can also vary in each pregnancy which is why some women report changes in their hair and some do not.