Most newborn jaundice can’t be completely prevented, but the single most effective thing you can do is feed your baby early and often. Frequent feeding in the first days of life stimulates bowel movements, which is how bilirubin (the yellow pigment behind jaundice) leaves your baby’s body. About 60% of full-term newborns develop some degree of jaundice, and in most cases it’s harmless and temporary. Still, there are concrete steps you can take before and after birth to lower the risk and catch problems early.
Why Newborns Get Jaundice in the First Place
Newborns produce about twice as much bilirubin as adults. This happens because their red blood cells have a shorter lifespan of roughly 52 days, compared to 120 days in adults, so more cells are breaking down at any given time. On top of that, the transfer of blood through the umbilical cord during birth delivers an extra load of red blood cells that will eventually break down into bilirubin.
The real bottleneck is the liver. A full-term newborn’s liver can process bilirubin at only about 1% of an adult’s capacity. Before birth, the placenta handled bilirubin removal. After birth, the baby’s liver has to take over a job it’s barely equipped for. It takes roughly 90 days for the liver’s processing ability to ramp up to a functional level. That gap between high bilirubin production and low processing power is why bilirubin levels typically peak around the third or fourth day of life and then gradually decline over the first week.
Feed Early, Feed Often
Feeding is the most important prevention tool parents have. Breast milk has a natural laxative effect, and bilirubin exits the body through stool. The more your baby poops, the more bilirubin gets flushed out. The Children’s Hospital of Philadelphia recommends breastfeeding a minimum of eight times per day, and waking your baby every two to three hours to feed during the early days.
Aiming for 10 to 12 feedings per day starting on day one is even better, particularly for preventing what’s sometimes called “breastfeeding failure jaundice.” This type of jaundice appears in the first few days and isn’t caused by breast milk itself. It’s caused by not getting enough of it. When a baby doesn’t feed frequently enough, fewer bowel movements occur, and bilirubin builds up. Making sure your baby has a good latch and is actually transferring milk (not just comfort sucking) is key. If you’re struggling with latch or milk supply, asking for help from a lactation consultant in the hospital can make a real difference.
Formula-fed infants tend to get jaundice less often, partly because they typically consume larger volumes early on (around 27 mL per feeding or about 150 mL per day in the first days). If your breastfed baby needs supplementation, small amounts of formula (10 to 15 mL) given right after breastfeeding can help keep bilirubin moving without undermining your milk supply.
Breastfeeding Jaundice vs. Breast Milk Jaundice
These two conditions sound similar but have different timing and different prevention strategies. Breastfeeding failure jaundice shows up in the first few days and is caused by insufficient intake. You can prevent it by feeding frequently and ensuring your baby is getting enough milk.
Breast milk jaundice is different. It appears after the first week of life in otherwise healthy, well-fed babies. Something in the milk itself slows bilirubin processing. This type cannot be prevented, but the good news is that it’s not harmful. It resolves on its own, usually within a few weeks, and rarely requires any intervention beyond continued monitoring.
Know Your Risk Factors Before Birth
Some babies are at higher risk for severe jaundice, and knowing this ahead of time lets you and your medical team prepare. Blood type incompatibility between mother and baby is one of the biggest risk factors. If you’re blood type O and your baby is type A or B, your antibodies can cross the placenta and break down the baby’s red blood cells faster, producing more bilirubin. Similarly, if you’re Rh-negative and your baby is Rh-positive, the same kind of immune reaction can occur.
Standard prenatal care screens for this. All pregnant women have their blood type and Rh status checked at the first prenatal visit, along with an antibody screen. Rh-negative women receive an injection of anti-D immune globulin during pregnancy and after delivery to prevent their immune system from attacking the baby’s red blood cells. If you know you have a blood type mismatch with your baby’s father, mention it to your care team so they can plan for closer bilirubin monitoring after birth.
Other risk factors include premature birth (even “late preterm” at 35 to 37 weeks), a sibling who had jaundice, significant bruising during delivery, and East Asian heritage.
How Bilirubin Gets Checked
Before you leave the hospital, your baby’s bilirubin level will likely be measured. There are two methods. A transcutaneous bilirubinometer is a small device pressed against the skin, usually the forehead or chest. It’s painless, gives an instant result, and works well as a screening tool. However, it tends to slightly underestimate bilirubin levels, and that underestimation grows worse as levels get higher. Once readings are elevated, a blood test (total serum bilirubin) is needed to confirm the exact level and guide any treatment decisions.
The 2022 American Academy of Pediatrics guidelines use the baby’s gestational age, age in hours, and bilirubin level to determine whether phototherapy is needed. The thresholds vary, so there isn’t a single “dangerous number” for all babies. A 35-week preterm baby, for example, has a lower threshold for treatment than a full-term baby. This is why hospital screening before discharge matters so much: it catches rising levels before they become a problem.
What About Sunlight?
You may have heard that putting your baby near a window helps with jaundice. Sunlight does contain the same wavelengths of light used in hospital phototherapy, which breaks down bilirubin in the skin. But medical organizations do not recommend sunlight as a reliable prevention or treatment strategy. The problem is that sunlight also contains ultraviolet and infrared radiation. A Cochrane review found that babies exposed to sunlight for jaundice treatment had a significantly increased risk of overheating, with roughly 1 in 3 babies in the sunlight groups developing elevated body temperatures. Newborns can’t regulate their body temperature well, so this is a genuine safety concern.
Filtered sunlight (blocking UV rays) has been studied in resource-limited settings as an alternative to phototherapy machines, but even with filters, the overheating risk remained high. Brief, indirect light exposure through a window isn’t dangerous in everyday life, but it shouldn’t be relied on as a treatment plan.
Watching for Jaundice at Home
Jaundice follows a predictable pattern on the body, spreading from head to toe as bilirubin levels rise. It typically appears first on the face and neck, then moves to the upper chest, then below the belly button to the thighs, then the arms and lower legs, and finally the palms and soles. The further down the body the yellowing extends, the higher the bilirubin level is likely to be. Yellowing that has reached the arms, legs, palms, or soles warrants a call to your pediatrician.
To check, press gently on your baby’s skin (the forehead or nose works well) and look at the color underneath as you release. In babies with darker skin tones, visual assessment is less reliable, so checking the whites of the eyes and the gums can be more helpful. If your baby seems unusually sleepy, is difficult to wake for feedings, isn’t producing enough wet or dirty diapers, or has a high-pitched cry, these are signs that bilirubin may be climbing and your baby needs to be checked.
A Practical Checklist for the First Week
- Start feeding within the first hour after birth and continue at least 8 to 12 times per day for the first several days.
- Don’t skip nighttime feedings. Wake your baby every two to three hours if needed.
- Track diapers. By day three or four, your baby should have at least three to four stools per day. Frequent, seedy yellow stools in a breastfed baby are a sign that bilirubin is being cleared.
- Get the bilirubin check before leaving the hospital. Ask about the result and whether a follow-up is recommended.
- Keep the follow-up appointment. Most babies should be seen by a healthcare provider within one to two days of hospital discharge, especially if discharged before 72 hours of age.
- Know your blood type. If there’s a potential mismatch, your baby may need closer monitoring.