In the vast majority of babies, the skin and the whites of the eyes turn slightly yellow on the second or third day after birth. This is called physiological jaundice. It usually peaks on the 3rd–5th days and resolves on its own within 1–2 weeks in healthy, full-term babies. There is no single "normal value" for jaundice that applies to everyone. The same number might require treatment for a 1-day-old baby, while it could be a completely expected value for a 4-day-old baby.
The first question in the minds of parents who come in a few days after discharge saying "my baby has turned yellow" is usually: "At what level is it dangerous?" The short answer is: It depends on the baby and the baby's age in hours. We explain why below.
Why do babies turn yellow?
A baby in the womb has more red blood cells to adapt to an environment with less oxygen. After birth, this excess is rapidly broken down, releasing bilirubin, a yellow-colored substance. The liver, which removes bilirubin from the body, is not yet working at full capacity in the first few days. Thus, bilirubin accumulates in the blood and gives the skin its yellow color.
In other words, for most babies, this is not a disease, but a transition period. Our job is to ensure we do not miss which baby exceeds this threshold.
Why is the jaundice level not evaluated with a single number?
Your doctor uses three pieces of information together when looking at the bilirubin level:
- The baby's age in hours: Since bilirubin naturally rises in the first few days, the treatment threshold also rises with each passing hour. Therefore, results are interpreted on an hourly basis, not daily.
- Gestational age: Treatment is initiated at lower values for babies born before 38 weeks. Separate charts are used for babies born before 35 weeks.
- Risk factors: Blood type incompatibility between mother and baby, G6PD enzyme deficiency, severe infection (sepsis), or low albumin in the blood lower the treatment threshold. A large scalp swelling (cephalohematoma) at birth does not change the threshold but may cause jaundice to rise higher.
Physicians evaluate these three pieces of information together using charts in international guidelines. Rules shared in forums such as "if jaundice exceeds 15, the baby is hospitalized" are therefore misleading. What is meaningful for your baby is the decision your doctor makes based on this chart.
How is the measurement done?
The initial assessment is often done through the skin (transcutaneous) with a device held to the forehead or chest. This method is painless and very useful for screening. If the result is close to the treatment threshold, blood is drawn from the heel or a vein to determine the exact value.
Visual assessment can be misleading. Jaundice tends to spread from the head to the feet. The spread of jaundice to the abdomen and legs may indicate that the level is rising. However, room lighting and the baby's skin tone make this assessment difficult. When in doubt, do not guess, get it measured.
Which jaundice is not normal?
Go to the emergency room without waiting
- High-pitched crying or arching the back like a bow
- Being too sleepy to be woken up, stopping breastfeeding completely
- Fever of 38 °C or higher, or the body feeling significantly cold
Consult a doctor on the same day
- Jaundice starting within the first 24 hours after birth
- Jaundice that increases rapidly or spreads to the abdomen, legs, and soles of the feet
- Being sleepier than normal, weakening of breastfeeding
- Light-colored (off-white, clay-colored) stool and dark-colored urine
Pay special attention to the color of the stool. A newborn's stool can be yellow, mustard-colored, or green. All of these are normal. However, jaundice accompanied by pale, whitish stool may indicate a blockage in the bile ducts. In bile duct obstruction (biliary atresia), results are much better when surgery is performed in the first 1–2 months. If you see pale stool, take a photo and show it to your doctor without delay.
Breastfeeding and jaundice: Two separate conditions
Jaundice can appear in two different ways in breastfed babies. These two are often confused.
Breastfeeding jaundice (due to insufficient intake) appears within the first week. If the milk has not fully come in or the baby cannot be breastfed effectively, the baby cannot excrete enough bilirubin through stool. The solution in this case is not to stop breastfeeding, but to increase it. It is recommended to breastfeed the baby 8–12 times a day. If necessary, support is obtained from a lactation consultant, and additional food is given upon your doctor's recommendation. The baby wetting at least 6 diapers a day and the stool turning yellow from the fourth or fifth day onwards are good signs that they are being fed sufficiently.
Breast milk jaundice is noticed after the first week and is seen in well-fed, gaining weight, healthy babies. It is associated with some substances in breast milk slowing down the excretion of bilirubin. It can last for a few weeks, sometimes 2–3 months. After other causes are ruled out, breastfeeding is continued. In most cases, no treatment is required.
When and how is phototherapy performed?
When the bilirubin level reaches the treatment threshold determined by the baby's age and risk status, light therapy (phototherapy) is started. The baby is placed under a special blue light with their eyes protected by a band and wearing only a diaper. This light converts the bilirubin in the skin into a form that can be excreted through urine and stool.
- Treatment usually lasts 1–2 days. The duration is determined by the rate at which bilirubin drops.
- Breastfeeding continues during treatment. The baby can be taken out of the light for short periods to breastfeed and is fed every 2–3 hours.
- Bilirubin is re-measured at regular intervals during and after treatment. The value may rise slightly after treatment is stopped. This is usually an expected situation.
More intensive treatment may be required for very high levels or rapid increases due to blood type incompatibility. These babies are closely monitored in the Neonatal Intensive Care Unit. Advanced treatments such as blood exchange are rarely needed today.
Common mistakes at home
- Giving sugar water or water: It does not reduce jaundice. It causes the baby to fill their stomach and take less milk, which can worsen the situation. No liquid other than breast milk or formula is given to the baby in the first six months.
- Yellow cover, yellow headscarf, wearing gold: It has no effect on bilirubin. It looks harmless but is risky because it delays the monitoring of jaundice.
- Skipping the follow-up appointment: Bilirubin usually reaches its highest level after discharge. This check is often planned within 1–3 days after discharge; do not miss the given day.
- Not waking the sleeping baby for feeding: Yellow babies can be sleepier. Wake the baby who sleeps longer than 3 hours in the first few days to feed.
Prolonged jaundice: What to do if it lasts longer than two weeks?
Jaundice lasting longer than two weeks in a full-term baby and three weeks in a premature baby is called prolonged jaundice. In this case, the baby is examined, and it is checked which type of bilirubin is high in the blood. Although the cause turns out to be breast milk jaundice in most babies, conditions requiring treatment such as thyroid functions, urinary tract infection, and bile duct problems must be ruled out at this stage.
Newborn jaundice follow-up at HRS
Phototherapy is among the services provided in our Neonatal Intensive Care Unit. You can make an appointment from our Department of Pediatrics for jaundice check-ups.
Physician who reviewed the article: Pediatrician Uzm. Dr. F. Barış Elverici. The recommendation of the physician examining your baby always comes first.
Disclaimer: The content on this page is for informational purposes only. Please consult your physician for diagnosis and treatment.
