Coombs' testing and neonatal hyperbilirubinemia

[The authors respond:]

We thank Stephen Wainer and colleagues for their comments on our recent article.¹ We agree that using any test in isolation, including the Coombs' test, is not the most effective way to identify infants at risk of neonatal hyperbilirubinemia. Our recommendation for Coombs' testing was not for all infants whose mothers had type O+ blood, only for those who had risk factors for hyperbilirubinemia or were already jaundiced at the time of discharge.

Despite existing guidelines from the American Academy of Pediatrics² and the Canadian Paediatric Society³ recommending identification of newborns at risk and close follow-up of these infants, our data clearly demonstrate that severe neonatal hyperbilirubinemia continues to occur at an alarming rate in Canada. The most common cause in our population was ABO incompatibility; this needs to be emphasized to pediatricians and primary health care practitioners.

Many strategies have been postulated as being cost-effective in preventing severe neonatal hyperbilirubinemia. We welcome the use of strategies coupling clinical suspicion of risk of hyperbilirubinemia at the time of discharge with close outpatient monitoring. Transcutaneous bilirubinometers, although very useful within a clinical context, may not always serve as a substitute for a serum bilirubin measurement when the bilirubin concentration reaches levels at which phototherapy is required.^4,5 No reported strategies using transcutaneous bilirubinometers have yet been proven to be cost-effective,⁶ largely because the prevalence of long-term neurological sequelae of severe hyperbilirubinemia is not yet known.