From 2007 to 2014 the New York State (NYS) Newborn Screening (NBS) program screened 2 million newborns for congenital adrenal hyperplasia (CAH). The data was analyzed to determine factors that affect 17α-hydroxyprogesterone levels and assist in developing algorithm changes that would improve the positive predictive value of the methodology being used. The concentration of 17-OHP in dried blood spots was measured using the AutoDELFIA Neonatal 17-OHP kit (Perkin Elmer, Turku, Finland). During the 8 year period of this study 2476 babies were referred, 105 babies were diagnosed with CAH (90 with the salt-wasting (SW), 8 with simple virilizing (SV), 5 with non-classical CAH, and 2 with another enzyme deficiency) and, 14 with possible CAH. Three false negative cases with SV-CAH were reported to the program. Of the total 108 known cases, 74 (69%) infants were detected by newborn screening in the absence of clinical information, or, known family history. The incidence of CAH in NYS is 1 in 18,170 with a ratio of SW to SV of 8.2:1. The incidence of CAH is lower in Black infants than in White, Hispanic and Asian infants. Despite a lower mean birth weight, female infants have a lower mean 17-OHP value than male infants and are under-represented in the referred category. As per other NBS programs the false positive rate is exacerbated by prematurity/low birth weight and by over-early specimen collection.

Universal newborn screening for human immunodeficiency virus (HIV) has been mandatory in New York State (NYS) since 1997. The goal of screening is to prevent mother-to-child transmission (MTCT) by using approaches including antiretroviral therapy (ART) in the newborn and lactating mother. Screening is performed using an enzyme-linked immunosorbent assay that detects maternal antibodies in dried blood spots from newborns. From January 2011 through November 2018 and from October 2022 through December 2024, the NYS Newborn Screening Program used the HIV-1 MicroELISA System to screen for anti-HIV-1 antibodies in these samples. Newborns who screened positive were referred to an infectious disease specialist for follow-up. During the period of this study, approximately 2.3 million newborns were screened for HIV-1 antibodies. Amongst 4018 newborns referred for follow-up, MTCT was confirmed in 16 newborns (0.4%), 3930 were uninfected (97.8%), 53 were lost to follow-up or were deceased (1.3%), and 19 newborns were considered to have false-positive HIV results (0.5%). MTCT occurred in one in 144,162 newborns screened during the study period, while one in 577 infants were considered to be at risk of vertical HIV transmission. The numbers of newborns who screened positive for HIV antibodies and were therefore at risk of MTCT as well as MTCT have both fallen from 2011 to 2024. NYS MTCT has been below 1% since 2015. To further reduce transmission risk, factors that contribute to loss to follow-up of infants exposed to HIV should be investigated.