Infants with neonatal hyperbilirubinemia, a condition often linked to hemolytic disease of the fetus and newborn (HDFN), may experience added heart strain when jaundice becomes severe, according to research published recently in Physiology Research.
Investigators found that newborns with higher levels of bilirubin also had increased concentrations of a blood marker that signals cardiac injury, while other common lab values showed no meaningful influence.
This study, conducted at JingMen People’s Hospital in Hubei Province, China, examined 82 infants treated for neonatal hyperbilirubinemia between September and December 2023. The babies were divided into a mild group with total bilirubin levels below 342 μmol/L and a severe group with levels at or above that threshold. While the groups were similar in birth weight, gestational age, sex, and delivery method, those with severe jaundice were slightly older at the time of testing.
Babies in the severe group had notably higher blood concentrations of high-sensitivity cardiac troponin I (median 64.1 ng/mL) compared with the mild group (median 41.9 ng/mL). Troponin is a protein released when heart muscle is injured, making it a reliable indicator of cardiac stress. The ratio of bilirubin to albumin, another marker of severity of jaundice, was also significantly higher in severe cases.
Read more about symptoms and risks of HDFN
In contrast, platelet counts and bile acid levels were similar between groups, suggesting these factors do not strongly influence troponin levels in this context. Statistical analyses confirmed that platelet counts and the bilirubin-to-albumin ratio did not significantly affect troponin results. However, a weak but significant correlation was observed between total bilirubin levels and troponin concentrations.
“Limitations of this study include the absence of neonates with extremely severe hyperbilirubinemia, which may limit the scope of the comparisons,” explained the authors of this research.
Researchers also explained that unconjugated bilirubin, the substance responsible for jaundice, can damage heart cells by triggering processes that lead to programmed cell death. Earlier studies have shown that even moderate bilirubin elevations can stress the heart, while more extreme levels may cause progressive myocardial injury.
For families affected by HDFN or other causes of severe jaundice, these results highlight the importance of careful monitoring. While the study does not prove that every baby with high bilirubin suffers lasting heart damage, it suggests that cardiac stress should be considered during treatment and follow-up. Early recognition and management of jaundice may help prevent not only brain-related complications but also subtle impacts on the heart.
Sign up here to get the latest news, perspectives, and information about HDFN sent directly to your inbox. Registration is free and only takes a minute.
