Some time ago, I had a “salty chat” with my friends over dinner, and they asked me several common questions about pediatrics. A few common phenomena of the neonatal period, which is also often asked when I check the room, I hope the long can reduce the anxiety and tension of parents. 1, the pioneer head The fetus through the birth canal delivery due to pressure on the head caused by the head of the soft tissues within the obstruction of blood circulation and deformation. Because the fetal head is larger than the birth canal, the fetal head is compressed by the soft tissues during the expansion of the birth canal, and the venous return is obstructed, resulting in extravasation of water and edema of the soft tissues of the scalp – that is, the pioneer head or the birth tumor. Because of the tightness of the birth canal in primiparous women, newborns delivered in the first cephalic position often have varying degrees of anterior head. The top of the head is long and olive-shaped, with indentation marks on finger pressure, and the edema can change with the direction of lateral sleep. The edema is usually absorbed 2~3 days after birth, but it takes 6~7 days for it to subside, so it is not treated. 2. Fetal lipid The fetal sebaceous glands in the 5th month of gestation begin to secrete lipid material – fetal lipid – to protect the skin from amniotic fluid immersion. It is generally most abundant on the body surface of premature babies, followed by full-term babies and least in term babies. After birth, fetal lipid protects the skin from infection and keeps the skin warm, but when the folds are acidic, it can irritate the skin and cause folds to rot. Therefore, the creamy white sticky fetal fat that accumulates in the folds under the fluid, groin and neck should be wiped off with sterile gauze dipped in oil, and some of the fetal fat can be absorbed by the skin. 3, birthmark This is caused by the accumulation of pigment cells in the deep layer of the skin. Most of them are located in the sacral tail in irregular shape of light cyan, pressure does not fade, the edge is clear. It usually fades on its own before school age and does not require treatment. The fetus has swallowed amniotic fluid in the maternal amniotic sac. The contents of amniotic fluid in the digestive tract, including keratinized epithelial cells, fetal hair, fetal fat, and amniotic gland secretions, bile, etc., are mixed into dark green meconium, which is sticky and odorless, and is generally emptied 1 to 3 days after birth, and can last up to 3 days or more. With the gradual increase in milk consumption and the emptying of feces, the color of the stool is changed from dark green to brown, and then gradually turned to yellow. Allergic erythema mostly occurs after bathing, and some newborns will have erythema on light, air, soap, towel, temperature and other stimuli, and many of them can be fused into patches. The erythema can be found on the face and trunk and extremities, with the trunk being more common and disappearing naturally in 2~3 hours. However, there are also fluctuations, and it will heal on its own in about a week, and no special treatment is needed. If the attack is particularly severe, a small amount of oral anti-allergy medication can be taken.