Hearing and neurodevelopmental outcomes for children with asymptomatic congenital cytomegalovirus infection: A systematic review.

INTRODUCTION: Congenital CMV is one of the commonest congenital infections and a recognised cause of sensorineural hearing loss and neurodevelopmental impairment. Ninety percent are clinically inapparent at birth but are reported to be at risk of developing such abnormalities throughout childhood, the extent of which requires further elucidation.

METHODS: A systematic literature review was conducted using Medline and Embase databases, manual citation review, and personal libraries for articles reporting primary data on hearing and neurodevelopmental outcomes for children with asymptomatic congenital CMV. PROSPERO registration number CRD42015025407.

RESULTS: Thirty-seven of 480 articles identified between 1969 and 2016 met the eligibility criteria. Twenty-nine of these contributed primary data on hearing outcomes and 20 on neurodevelopmental outcomes (12 of the 37 studies contributed data on both). Cumulative incidence of sensorineural hearing loss with follow-up to at least 5 years was 7% to 11%, which is more than healthy controls but less than children with symptomatic congenital CMV (34%-41%). The onset, course, and severity of hearing loss was variable with no reliable virological prognostic marker. In comparison to controls, children with asymptomatic congenital CMV did not perform worse than controls in neurodevelopmental assessments and performed better than children with symptomatic congenital CMV.

CONCLUSIONS: Studies show children with asymptomatic congenital CMV are at increased risk of developing hearing loss but perform equally well on neurodevelopmental assessments when compared with healthy controls. There is no reliable virological marker to determine which infants will develop sequelae. Regular follow-up until school entry is supported by the literature.