To the Editor We read with interest the article by Weimer et al,1 which suggested that postnatal cytomegalovirus (CMV) infection is associated with a higher incidence of failed newborn hearing screening, lower weight, and prolonged stay in the neonatal unit. We noted that there was no significant difference in head circumference at discharge/postmenstrual age of 40 weeks between the CMV group and the control group. However, it is well established that antenatal CMV infection can result in microcephaly and is associated with developmental problems.2 We were wondering whether postnatal CMV infections affected head circumference growth patterns.