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What are lanugo hairs and when do they cover a fetus’s body?
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pregnancy
Devices for individual use at home detect pregnancy by measuring levels of the hormone human chorionic gonadotropin (hCG) in urine.
Lanugo is a layer of soft, downy, and slender hair that develops on the fetus during prenatal development.12
These hairs typically begin to grow during the third or fourth month of fetal life. By the fifth month, this downy coat covers the fetus's body. Lanugo is temporary and is entirely shed either before or shortly after birth, as the skin of a full-term infant is typically free of this hair.12