SAT-LB050 Congenital Adrenal Hyperplasia Newborn Screening Protocols Differ Widely in the US: A Survey by the Differences/Disorders of Sex Development Translational Research Network (DSD-TRN)

All 50 United States and the District of Columbia incorporate newborn screening for congenital adrenal hyperplasia (CAH) caused by 21-hydroxylase deficiency. Filter paper blood specimens are typically collected in full-term infants on day two of life for 17-hydroxyprogesterone (17OHP) fluoroimmunoassay (DELFIA). Prematurity, low birth weight, or critical illness are known to cause falsely elevated results. Protocols differ for each state laboratory as to assay cut-points by birthweight or gestational age, which are key in determining the positive predictive value. As a preliminary step to quality improvement, we investigated the diversity of approaches to CAH screening nationally among the states representing members of the DSD-Translational Research Network. Ten data sets were returned from a survey circulated to state laboratory directors with qualitative and quantitative information about individual screening programs. Disease incidence generally correlated with published worldwide data, ranging from 1:10,000 to 1: 28,500 live births. Screening results are typically reported by direct phone call to the designated healthcare provider and/or coordinator at each referral center, followed by a faxed written report. Specialists are notified of unequivocally high 17OHP results; however, borderline results are not usually referred to a pediatric endocrinologist. Only one state laboratory required a mandatory second screen for healthy term infants regardless of initial screen result; most did for infants in intensive care units. Nine of 10 programs utilized birthweight cut-points, but cutoffs for normal results varied widely - from 17OHP values of 25 to 75 ng/mL for birthweights >2250-2500 grams. One program used gestational age cut-points. The positive predictive values for term or normal birthweight infants varied from 1.2 to 9.6%, implying differences in sensitivity and/or specificity of screening between states. There was no apparent correlation between the total number of infants each state screened annually, assay cut-point and positive predictive value. Data were unavailable for negative predictive values. Conclusion: There is a need for standardization of newborn screening protocols for CAH to improve the positive predictive value. Future efforts will be directed to expanding this survey and determining best practices. Unless otherwise noted, all abstracts presented at ENDO are embargoed until the date and time of presentation. For oral presentations, the abstracts are embargoed until the session begins. Abstracts presented at a news conference are embargoed until the date and time of the news conference. The Endocrine Society reserves the right to lift the embargo on specific abstracts that are selected for promotion prior to or during ENDO.