Congenital cytomegalovirus infection results from intra-uterine fetal infection by cytomegalovirus (CMV).
CMV is the most common cause of intra-uterine infection and most common cause of congenital infective and brain damage, occurring in 0.2-2.4% of live births.
Antibodies to CMV are seen in 30-60% of pregnant women, but only 2.5% have a primary infection during pregnancy, and this can result in fetal infection in ~30% of cases.
The vast majority (90%) of infected babies are asymptomatic at birth, but some may go on to develop symptoms after 6-9 months. Some countries now keep spots of neonatal blood on special filter paper (Guthrie cards) for CMV DNA testing at a later date if needed.
Possible signs and symptoms include:
- sensorineural deafness
- mental retardation
The degree of neurological impairment is variable, from mild learning and behavioral problems to mental retardation and physical handicaps.
Cytomegalovirus (CMV) is a DNA virus in the herpes virus family which has the propensity to cause intrauterine infections and is part of the group referred to as TORCH infections.
- fetal intracranial calcification: mainly periventricular calcification (hyperechogenic foci), considered on the commonest of features 6
- fetal hydrocephalus
- heterogeneous appearing parenchyma
- intraventricular adhesions
- fetal intra-hepatic calcification
- fetal hepatomegaly
- evidence of intra-uterine growth restriction (IUGR)
- echogenic bowel
These findings are associated with poor outcome, allowing mothers to consider termination of the pregnancy if identified early enough.
When performed postnatally, non-contrast CT demonstrates variable features, including:
- intracranial calcifications: particularly thick and chunky in germinal matrix and periventricular regions with faint and punctate basal ganglia calcifications
- white matter low density regions
- ventriculomegaly/cerebral atrophy/destructive encephalopathy
- neuronal migration disorders
Features seen on MRI include:
- migrational abnormalities: lissencephaly, pachygyria, and schizencephaly
- white matter lesions: predominantly parietal or posterior white matter involvement with spared rim in immediately periventricular and subcortical white matter.
- ventriculomegaly and subarachnoid space enlargement
- delayed myelination
- periventricular and temporal pole cysts
- 1. Van der knaap MS, Vermeulen G, Barkhof F et-al. Pattern of white matter abnormalities at MR imaging: use of polymerase chain reaction testing of Guthrie cards to link pattern with congenital cytomegalovirus infection. Radiology. 2004;230 (2): 529-36. doi:10.1148/radiol.2302021459 - Pubmed citation
- 2. Kapilivsky A, Garfinkle WB, Rosenberg HK et-al. US case of the day. Congenital cytomegalovirus (CMV) brain infection. Radiographics. 1995;15 (1): 239-42. Radiographics (citation) - Pubmed citation
- 3. Malinger G, Lev D, Zahalka N et-al. Fetal cytomegalovirus infection of the brain: the spectrum of sonographic findings. AJNR Am J Neuroradiol. 2003;24 (1): 28-32. AJNR Am J Neuroradiol (full text) - Pubmed citation
- 4. Nigro G, Mazzocco M, Anceschi MM et-al. Prenatal diagnosis of fetal cytomegalovirus infection after primary or recurrent maternal infection. Obstet Gynecol. 1999;94 (6): 909-14. - Pubmed citation
- 5. Entezami M, Albig M, Knoll U et-al. Ultrasound Diagnosis of Fetal Anomalies. Thieme. (2003) ISBN:1588902129. Read it at Google Books - Find it at Amazon
- 6. Ceola AF, Angtuaco TL. US case of the day. Congenital cytomegalovirus infection. Radiographics. 19 (5): 1385-7. Radiographics (full text) - Pubmed citation
- 7. Fink KR, Thapa MM, Ishak GE et-al. Neuroimaging of pediatric central nervous system cytomegalovirus infection. Radiographics. 2010;30 (7): 1779-96. doi:10.1148/rg.307105043 - Pubmed citation