Phenylketonuria screening: effect of early newborn discharge

To determine the percentage of term newborns discharged by 24 hours of life and the actions taken by physicians and institutions to avoid false-negative phenylketonuria (PKU) screens in these infants.

Descriptive cross-sectional survey.

One hundred forty term nurseries and 157 pediatricians.

Stratified sampling techniques were used to sample nurseries from the 1992 American Hospital Association guide to provide equal representation of each region of the country. Pediatricians were systematically sampled from a national list of practicing pediatricians supplied by Ross Laboratories to provide equal sampling from each state.

The response rates were 95% (n = 133) for term nurseries and 83% (n = 131) for pediatricians. Twenty-four percent of healthy newborns are discharged by 24 hours of life. Ninety-three percent of nurseries screen all infants for PKU before discharge. In states without laws mandating rescreening, only 48% of institutions that discharge the majority of their infants (> 50%) by 24 hours of life rescreen. Also, in states without rescreening laws, 64% of pediatricians rescreen. The timing of this repeat screen ranges from less than 72 hours of life to 4 weeks. Determining which infants to rescreen varies by practitioner; some rescreen all infants, whereas others rescreen those discharged early. Just more than half of all pediatricians, whether practicing in a state requiring repeat PKU screening, claim to be familiar with the American Academy of Pediatrics recommendations regarding repeated PKU screening of infants discharged by 24 hours of life.

Twenty-four percent of term newborns in the United States are discharged by 24 hours of life. Most hospitals screen all infants for PKU before discharge regardless of age. The majority of states do not mandate rescreening; rescreening policies among pediatricians and institutions in those states vary widely. A significant number of infants do not receive repeated screening and are therefore at risk for delayed or missed diagnosis of PKU because of insensitive initial screens. Pediatrician awareness of the need to perform repeated PKU screens on infants discharged by 24 hours is poor.