Congenital Cytomegalovirus Testing Following Pennsylvania Hearing-Targeted Screening Legislation

BACKGROUND Congenital cytomegalovirus infection (cCMV) occurs in approximately 1/200 to 1/250 US newborns each year and can cause progressive sensorineural hearing loss. Since 2022, Pennsylvania law mandates cCMV testing for infants who fail newborn hearing screening. OBJECTIVES To assess changes in cCMV testing rates and diagnosis before and after Pennsylvania hearing-targeted legislation. METHODS Retrospective cohort study of all live births at 3 university-affiliated birth centers. We identified all infants tested for CMV at 21 days of age or younger and analyzed cCMV testing rates in pre- (January 2018-June 2022) and post- (July 2022-December 2024) legislation eras using interrupted time-series analysis. We assessed other clinical signs associated with cCMV testing using standard statistics. RESULTS The study cohort included 85 324 infants. Among 54 909 born prelegislation, 3168 (5.8%) had cCMV testing; among 30 415 born postlegislation, 3197 (10.5%) were tested. cCMV testing rates increased significantly among term (by 3.2%) and preterm infants (by 15.5%) at the beginning of the postlegislation era (P = .003 and .001, respectively). Among 5224 infants with hearing-based criteria for screening, CMV testing increased from 36.7% prelegislation to 74.0% postlegislation (P < .001). In the postlegislation period, testing associated with isolated microcephaly increased, but isolated small for gestational age–associated testing decreased. Among 61 infants diagnosed with cCMV, 16 (26.2%) were identified based on hearing criteria alone (2.3/1000 infants prelegislation, 6.0/1000 infants postlegislation, P = .04). CONCLUSIONS CMV testing and diagnosis based on hearing criteria alone increased significantly post passage of Pennsylvania hearing-targeted cCMV testing legislation, but infants tested for hearing criteria alone accounted for less than half of identified cCMV cases.