Birth prevalence rates of newborn screening disorders in relation to screening practices in the United States.

OBJECTIVE

To examine the associations between the first-tier-screening laboratory methods and criteria and the birth prevalence of congenital adrenal hyperplasia (CAH), phenylketonuria (PKU), and the sickle hemoglobinopathies occurring in the United States between 1991 and 2000.

STUDY

DESIGN

By using validated data from the National Newborn Screening and Genetics Resource Center, we fit Poisson regression models with laboratory methods and criteria used in every year for each state for each disorder. We also examined whether there was an overall change in birth prevalence over the decade and whether there was an effect resulting from obligatory second screenings.

RESULTS

There were no associations among any of the factors and the birth prevalence of PKU in this decade. Use of the enzyme-linked immunosorbent assay was more likely than any other laboratory method to identify cases of CAH (OR 1.16; 95% CI 1.04-1.30), but no other factors were associated with this disorder. None of the factors examined were associated with the birth prevalence rates of any of the sickle hemoglobinopathies.

CONCLUSION

There were no substantial changes in the birth prevalence rates of PKU, CAH, or the sickle hemoglobinopathies over the study period despite rapid changes in technology.