Callosal Injuries in Cytomegalovirus Fetopathy: A Neurosonographic Study.

Introduction: Among the fetal brain anomalies described in cases of congenital infection, callosal insults are rarely cited in medical literature. The aim of this study was to describe the rate and pattern of callosal injury in cytomegalovirus (CMV) fetopathy.

Methods: This retrospective study included fetuses with confirmed CMV-PCR, assessed in a single center. Demographic data including maternal seroconversion info were collected. Dedicated US including neurosonography was performed, with high frequency probes, using TV route whenever feasible. Fetal brain biometry including callosal length and the corpus callosum (CC)/OFD ratio was performed. Length below the 5th centile or morphological abnormalities were considered abnormal. Brain and body morphology were thoroughly assessed, and any abnormal finding reported.

Results: Seventy-two patients were included in our cohort. In 76% infection occurred in the 1st T or periconceptional. In 12 patients, the exact time of infection was inconclusive, including two cases of secondary infection. In 34.7%, a callosal anomaly was observed and it was never isolated. CNS abnormalities included: periventricular hyperechogenicity (PVHE) 55.5%, calcifications 52%, ventriculomegaly 33%, periventricular pseudocysts 31.4%, occipital cysts 22.2%, echogenic ganglionic eminence 30.5%, lentostriatal vasculopathy 26.4%, sulcation abnormalities 22.2%, cerebellar findings 18% and HC below -2 SD 18%. In 19 cases, the CC was short with calcifications in four. In one case, the insult was severe and in another the CC was absent. The most common association with CC insult was PVHE (56%) and calcifications (52%).

Conclusion: Although not referred as a classic brain structure affected by CMV infection, the CC was injured in one-third of our patients, including cases of late infection. The mechanism of disease and the prenatal patterns of callosal involvement in these cases appear to be different from the postnatal patterns and are not reversible. The presence of a callosal injury would imply a worse prognosis and significant increment to the risk of neurodevelopmental impairment.