Congenital cytomegalovirus diagnosis: healthcare claims data of linked pregnant people-infant pairs, United States, 2018-2023.

Objective: To describe maternal demographics and compare clinical characteristics of infants with congenital cytomegalovirus (cCMV) identified through diagnostic codes and laboratory data in the United States during 2018-2023.

Methods: We used a CDC-licensed subset of HealthVerity data, which contained linked pregnant people-infant claims data from publicly and privately insured individuals during 2018-2023 (2023 Quarter 3 HealthVerity Maternal Outcomes Masterset data). We identified infants with cCMV using diagnostic codes or positive laboratory test results within 45 days of birth.

Results: Among 744 (4.6 per 10,000 live births) infants with cCMV during 2018-2023, 599 (81%) were identified by a diagnostic code only. Among 732 linked pregnant people, 91 (12%) had a diagnosis of CMV infection during pregnancy, with a similar distribution by age group and insurance type, but a lower proportion were Black as compared to those without CMV infection during pregnancy (14% vs. 29%, respectively). Overall, 452 (61%) infants had ≥1 cCMV-related clinical sign at birth and 185 (25%) had valganciclovir prescriptions. Eighty-eight (68%) infants identified by a positive laboratory test only had no cCMV-related signs and none had valganciclovir prescriptions.

Conclusions: Using healthcare claims data, we found a minimal overlap of cCMV identified by diagnostic codes and laboratory test results. A minority of linked pregnant people with infants with cCMV had a CMV diagnosis during pregnancy. cCMV surveillance will help better understand the validity of ICD codes to identify infants with cCMV, describe the spectrum of disease, and monitor the use of antivirals.