Study shows infants with high bilirubin levels no more likely to suffer long-term developmental problems than other infants
OAKLAND, Calif., May 3, 2006 — Newborn babies who are diagnosed with and treated for jaundice are no more likely than other babies to suffer long-term developmental problems, according to a study in this week’s New England Journal of Medicine.
The study, by researchers from Kaiser Permanente’s Division of Research and the University of California, San Francisco, is good news for parents because about 60 percent of newborns develop jaundice, and it’s one of the most common reasons babies are re-hospitalized after birth.
“These are reassuring results” said Thomas B. Newman, MD, MPH, an investigator at Kaiser Permanente’s Division of Research and UCSF, and the principal investigator of the study. “Our research shows that when severe jaundice is detected and treated properly we can prevent long-term neurological problems.”
Jaundice is a common condition in newborns. It refers to the yellow color of the skin and eyes caused by excess levels of bilirubin in the blood. Bilirubin is produced by the normal recycling and replacement of red blood cells. In adults the liver processes the bilirubin, but in newborns the liver is still immature and often unable to break bilirubin down fast enough, so levels build up. In a newborn the bilirubin rises rapidly in the first few days after birth, peaking below 15 milligrams per deciliter (mg/dL) in about 90 percent of newborns. Levels of 30 mg/dL or more can lead to a condition called kernicterus, which can cause deafness, cerebral palsy, brain damage or even death.
Kernicterus is rare, however, and little research has been done on infants who have bilirubin levels that are elevated, but below the 30 mg/dL mark. In this study researchers compared 140 infants with bilirubin levels 25 or more, a level reached by only about one in 700 newborns, to more than 400 control infants.
The researchers followed the children up to five years of age, measuring IQ, doing neurological exams and interviewing parents. They found no significant difference between jaundiced and control newborns in their IQs or behavior, or in the proportion of children with abnormal neurological examinations, or with neurological diagnoses.
The usual treatment for infants with elevated bilirubin levels is phototherapy. The baby is exposed to bright light which is absorbed through the skin, altering the bilirubin, making it easier for the baby’s liver to get rid of it.
“Having a child in the hospital receiving phototherapy can be frightening for parents,” said Gabriel J. Escobar, MD, a co-investigator at the Kaiser Permanente Division of Research. “This study should assuage some of those families’ concerns.”
Other study co-authors include Petra Lijestrand, PhD of Kaiser Permanente’s Division of Research; Rita J. Jeremy, PhD; Donna M. Ferriero, MD; Yvonne Wu, MD, MPH; and Esther Hudes, PhD, MPH all of UCSF.
The Kaiser Permanente Division of Research conducts, publishes, and disseminates epidemiologic and health services research to improve the health and medical care of Kaiser Permanente members and the society at large. It seeks to understand the determinants of illness and well being and to improve the quality and cost-effectiveness of health care. Currently, DOR’s 400-plus staff is working on more than 250 epidemiological and health services research projects.
UCSF is a leading university that consistently defines health care worldwide by conducting biomedical research, educating graduate students in the life sciences, and providing complex patient care.