Lannugo hair

Lanugo hair refers to the fine, soft, and usually colorless hair that covers the body of a fetus in the womb. This type of hair begins to develop around the fourth month of pregnancy and plays an important role in regulating the fetus's body temperature and protecting the skin. Lanugo hair is particularly light and fine, which allows it to form a protective layer that, together with the vernix caseosa, a waxy protective layer on the fetus's skin, shields the fetus from harmful bacteria

protects against drying out in the amniotic fluid.

Towards the end of pregnancy, usually in the last trimester, the lanugo hairs begin to fall out and are expelled into the amniotic fluid by the vernix caseosa. At birth, some babies still have remnants of lanugo hair on their skin, especially on the shoulders, back, and face, but these hairs usually fall out on their own within the first few weeks of life. They are then expelled by the so-called Vellus hair It replaces hair that is finer and thinner than the terminal hair we typically have on our head, eyebrows, and eyelashes.

The amount and distribution of lanugo hair can vary from baby to baby. Some newborns may have very little lanugo at birth, while others may have a more pronounced layer. This is usually nothing to worry about and simply represents a variation in normal development.