The reasons for the formation of fetal lipids in newborns are divided into internal and external causes, internal causes such as vigorous metabolism of the fetus, external causes such as pregnant women in pregnancy intake of nutrients is more adequate, and so on, need to be specifically analyzed. 1. Endogenous causes: the fetus in the growth of the metabolism is more vigorous, sebaceous glands are more active, easy to secrete more sebum, sebum attached to the surface of the skin, will form a layer of milky white oily material, thus playing a role in protecting the skin. 2. External factors: pregnant women in pregnancy intake of nutrients is more adequate, these nutrients are absorbed by the fetus through the umbilical cord can promote its metabolism, so that the fetus secretion of more sebum, thus the formation of fetal fat. Fetal fat of newborns is usually absorbed within 1 to 2 days after birth, and parents are advised not to wash it away with water or wipe it off with gauze. If there are any abnormalities such as redness and swelling of the skin of the newborn, it is recommended to consult a doctor in time. Under the doctor’s guidance, complete the relevant examinations to clarify the cause of the disease and provide symptomatic treatment.