The information on this website describes the outcome of congenital cytomegalovirus infection for a population of individuals who received care at the hospitals within the NICHD MFMU Network between 2012 and 2018. The data is from the MFMU Network Randomized Trial to Prevent Congenital Cytomegalovirus1. In this trial, individuals were included if they had primary CMV infection, defined as detectable plasma CMV-specific IgM and CMV-specific IgG with avidity <50% before 24 weeks or IgG seroconversion before 28 weeks, and were carrying a singleton fetus without ultrasound findings suggestive of CMV infection.

PLEASE NOTE: Information from this website is not intended to be the only basis for making care decisions for an individual, nor is it intended to be a definitive means of assessing the chance of congenital cytomegalovirus infection after maternal primary infection. Users should keep in mind that every patient is an individual, and that factors beyond those described on this website influence congenital cytomegalovirus infection.


  1. Hughes BL, Clifton RG, Rouse DJ, et al. A Trial of Hyperimmune Globulin to Prevent Congenital Cytomegalovirus Infection. N Engl J Med. 2021;385(5):436-444. doi:10.1056/NEJMoa1913569.

Version 1.0 (published August 2021)