Early skin-based bilirubinBilirubin A yellow substance produced when red blood cells break down. High bilirubin levels in newborns with HDFN can cause jaundice or, in severe cases, brain damage. testing can help detect potentially life-threatening jaundiceJaundice A common symptom of HDFN, jaundice is caused by excess bilirubin and is characterized by a yellow tint to the skin or eyes. in newborns affected by hemolytic disease of the fetus and newborn (HDFN), particularly when caused by ABO blood type incompatibility, according to a large hospital study published recently in the Egyptian Pediatric Association Gazette.
These findings suggest that simple, painless checks in the first days of life can identify babies who need closer monitoring or treatment before bilirubin levels become harmful. HDFN occurs when a mother’s immune system reacts against her baby’s red blood cells. In ABO-related HDFN, this most often happens when a mother has blood groupBlood group A classification of blood based on inherited markers found on red blood cells. The ABO and Rh blood groups are most common in HDFN. O and the newborn has blood group A or B.
The breakdown of red blood cells releases bilirubin, which can build up quickly and cause jaundice. If levels rise too high, bilirubin can damage the brain, making early detection critical for families and clinicians.
Researchers reviewed records from 1,455 healthy full-term newborns born to O-positive mothers between 2017 and 2019. All babies had transcutaneous bilirubin measured within 24 hours of birth and again over the first 5 days of life.
Read more about testing and diagnosis of HDFN
Elevated bilirubin was defined as greater than 4 mg/dL initially and greater than 10 mg/dL on follow-up. Overall, 29.4% developed high bilirubin in the first 24 hours and 35.8% during follow-up. About 6.17% developed HDFN severe enough to require treatment.
Babies with blood group A or B were at much higher risk. Their odds of elevated bilirubin were up to 10 times higher than babies with other blood types. A history of miscarriage, stillbirth or siblings with newborn jaundice also increased risk, as did breastfeeding in the first day of life. Most newborns, 95.3%, required only careful follow-up. PhototherapyPhototherapy A treatment that uses special blue light to help newborns break down bilirubin and prevent kernicterus. was needed in 3.8%, and exchange transfusion in 0.9%, all within the first day.
“Long-term follow-up of cases with severe hyperbilirubinemiaHyperbilirubinemia A common cause of jaundice, this refers to higher than normal bilirubin levels in the blood. is required to monitor for the long-term consequences, e.g., hearing defects and cognitive defects,” explained this study’s authors.
For families, these results mean that early skin bilirubin checks can offer reassurance or prompt action. The tests helped predict which babies with ABO-related HDFN were likely to develop serious jaundice using cutoffs of 3.75 mg/dL initially and 10.05 mg/dL on follow-up. This approach supports safer discharges, fewer surprises at home and earlier treatment when needed.
This study reinforces that ABO incompatibility is a common cause of HDFN but severe outcomes are uncommon when screening and follow-up are done well. For parents, asking about bilirubin screening and follow-up plans before leaving the hospital may help protect newborns during this vulnerable first week of life.
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