Why do newborns have physiological jaundice? Do they need treatment?

Author: Wang Yajuan, Chief Physician, Children's Hospital, Capital Institute of Pediatrics

Reviewer: Zou Liying, Chief Physician, Beijing Obstetrics and Gynecology Hospital, Capital Medical University

Neonatal jaundice can be divided into physiological and pathological. Physiological jaundice usually begins to appear 2-3 days after birth and reaches its peak in 5-7 days. For full-term infants, it usually disappears in 7-10 days and no longer than 2 weeks; for premature infants, it usually disappears in 3 weeks and no longer than 4 weeks.

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Neonatal physiological jaundice is a normal process. Except for the yellowing of the skin and sclera, the child's mental state, bowel movements and urination are normal. About 60% of full-term infants will experience it, and about 80% of premature infants will experience it.

1. Why do newborns have physiological jaundice?

Jaundice involves bilirubin metabolism, which is different for newborns than for adults. It is mainly due to excessive red blood cell destruction, short life span of newborn red blood cells, etc., which lead to excessive bilirubin production; the liver function of newborns is immature, and the ability of liver cells to process bilirubin is poor; the liver-enteric circulation of newborns is increased. All these reasons make newborns prone to physiological jaundice.

Physiological jaundice in newborns can be seen with the naked eye as yellowing of the skin and sclera, with the main symptom being elevated indirect bilirubin, and the bilirubin value is within a certain physiological range. The time when jaundice appears and disappears is within the normal range. If the child has no other abnormal manifestations, it can be judged as physiological jaundice.

If jaundice appears within 24 hours of birth, bilirubin exceeds the maximum value, exceeds the normal disappearance time, direct bilirubin exceeds 1.5 mg/dl, and jaundice subsides and reappears, pathological jaundice should be considered.

2. Does physiological jaundice in newborns need treatment?

Neonatal physiological jaundice is a natural process that occurs in more than half of newborns and will subside naturally, so there is no need for treatment or medication. Ensuring that the child is well fed and well-drinked, and that bowel movements are smooth, will help to metabolize bilirubin and help reduce jaundice.

Parents can observe closely during this period, mainly observing the child's feeding, mental reaction, and weight gain. After the physiological weight loss period, the weight can increase by 20-30 grams per day, and the appearance, properties, frequency, and amount of urine and feces are normal. Pay attention to the onset and disappearance time of jaundice, as well as the changes in jaundice, and rule out pathological jaundice.

If parents are anxious, they can let the newborn baby bask in the sun, which can promote bilirubin metabolism and help reduce jaundice. When basking in the sun, expose the skin as much as possible, but cover sensitive parts such as the eyes and perineum, and make sure the ambient temperature is appropriate.

Sunbathing through glass is also effective, but the effect will be better without glass. In summer, the sun is strong, so to avoid sunburn, it is generally recommended to sunbathe before 10 am and after 4 pm, as the sun is not as abundant during this period. Sunbathing should not be too long, generally 5-10 minutes. If the child is comfortable and cooperative, a little longer is fine. In addition, children may sweat when exposed to the sun, so pay attention to replenishing water to avoid dehydration.

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3. Does physiological jaundice in newborns require regular monitoring of bilirubin?

The severity of neonatal jaundice can generally be judged simply with the naked eye. If the yellowing extends from the face to the neck, the bilirubin level is generally around 6mg/dl; if the yellowing extends to the trunk, the bilirubin level is generally around 9mg/dl; if the yellowing extends to the knees, the bilirubin level is generally around 12mg/dl. This range is actually acceptable, and parents can observe closely. If you are not sure, you can go to a community hospital to see a doctor and have a transcutaneous bilirubin test.

If the face and trunk have jaundice, but the color is not heavy, and the child is generally in good condition, parents can observe at home without frequent visits to the hospital for bilirubin testing. If the jaundice is severe, the limbs, palms and soles are yellow, or the stool is light in color, even white, or has some special color, the child is in a bad mental state, has poor feeding, or the jaundice does not subside for a long time, then you must go to the hospital for treatment.