Prenatal ultrasonographic diagnosis of fetal cerebral ventriculitis associated with asymptomatic maternal cytomegalovirus infection

Is it not time for international guidelines to combat congenital cytomegalovirus infection? A review of central nervous system manifestations

Cytomegalovirus (CMV) is the most commonly transmitted virus in utero with a prevalence of up to 1.5%. The infection has potentially debilitating and devastating consequences for the infected fetus, being a leading cause for neurological disability worldwide. Once acquired, it often goes undetected with only an assumed 10% of infected neonates displaying the classic clinical or imaging features. Viral DNA polymerase chain reaction (PCR) of saliva or urine obtained within the first 21 days of life is required to make the diagnosis. As the majority of infected neonates are initially asymptomatic, diagnosis is often delayed. An abnormal routine neonatal hearing test and characteristic antenatal cranial ultrasound imaging findings may raise the suspicion of congenital CMV (cCMV) in the asymptomatic group. Ultimately, the aim is to facilitate early diagnosis and timely treatment. In this article, we highlight diagnostic and treatment challenges of the commonest congenital infection, we present the current available central nervous system imaging severity grading systems, and highlight the need for an internationally agreed diagnostic grading system that can aid treatment decision-making.

Effect of cytomegalovirus infection on temporal lobe development in utero: quantitative MRI studies

Several environmental factors, including viral infections during fetal development, are known to increase the risk of schizophrenia. Cytomegalovirus (CMV) is the main cause of viral congenital infection. Since changes in temporal lobe structures are a consistent finding in imaging studies of adult schizophrenics, we investigated possible derangement in temporal lobe development in CMV infected fetuses. Abdominal MRI (1.5 T) was performed using a single-shot fast spin echo T2-weighted sequence. MRI volumetry was employed to measure brain and temporal lobe size in 27 CMV infected fetuses and 52 gestational age matched controls in utero. The ratio of temporal lobe to whole brain was computed for each fetus and group comparisons were performed using Student's t-test or ANOVA. Temporal lobe volumes, normalized to whole brain and co-varied with gestational age; were significantly smaller in fetuses infected with CMV compared to uninfected fetuses. (Infected group mean ± SEM: 0.086 ± 0.006, controls: 0.113 ± 0.003, p<0.0001). Infection during the 1st and 2nd trimester had a more pronounced effect than infection during the 3rd trimester. Infected fetuses with no MRI findings had significantly lower temporal lobe/whole brain ratios than controls (0.092 ± 0.008, p<0.01, N=11) and the lowest ratios were observed in fetuses with overt findings such as cysts or gray matter heterotopy (0.067 ± 0.015). These results demonstrate the ability of quantitative fetal brain MRI to detect previously unreported, specific deficits in brain development in CMV infected fetuses, which, in conjunction with other genetic and environmental factors, may contribute to the risk of developing schizophrenia later in life.

Is fetal gender a risk factor for severe congenital cytomegalovirus infection?

Cytomegalovirus is the main cause of congenital viral infection and amniotic fluid viral load appears to be the single nonclinical prognostic factor. However, as in other infectious diseases, host genetics may influence the severity of the disease. To test this hypothesis, we looked retrospectively at the fetal gender in cases of severe congenital cytomegalovirus infection in our database. We also analyzed the international English literature covering this subject between 1985 and 2003. The proportion of females with brain abnormalities was statistically different from that of males (62/258: 24% vs 30/251: 12%, p = 0.004). The risk of abnormal brain development in infected fetuses was twice as high in females than in males (Chi(2) = 8.7; OR = 2, IC [1.26-3.21]). In our cases, amniotic fluid CMV DNA load was not significantly higher in males than in females (p = 0.06) and was also similar in severely and non-severely infected fetuses (p = 0.09).

Subependymal pseudocysts in the fetal brain: prenatal diagnosis of two cases and review of the literature

Subependymal pseudocysts are cerebral cysts found in 5% of all neonates. When they are isolated and typical, they result from persistence of the germinal matrix, have a good prognosis and regress spontaneously within a few months. However, associated anomalies are frequent and in such cases the prognosis is poor. They can be of infectious, vascular, metabolic or chromosomal origin. Subependymal pseudocysts have rarely been described in the antenatal period. We report the prenatal diagnosis of two cases of isolated pseudocysts at 32 and 23 weeks. Both ultrasonography and magnetic resonance imaging assisted in the diagnosis and there was normal postnatal outcome in both cases.

Prenatal diagnosis of congenital cytomegalovirus infection in 189 pregnancies with known outcome

Prenatal diagnosis (PD) of fetal cytomegalovirus (CMV) infection was performed in 242 pregnancies, with known outcome in 189 cases. In 141/189 pregnancies, PD was carried out on account of suspicious maternal CMV serology up to gestational week (WG) 23, and in 48 cases on account of abnormal ultrasonic findings detected between WG 18 and 39. Chorionic villus samples (n = 6), amniotic fluid (AF, n = 176) and/or fetal blood specimens (n = 80) were investigated for detection of virus by cell culture, shell vial assay, PCR and/or CMV-specific IgM antibodies. Of 189 fetuses correctly evaluated by CMV detection either in fetal tissue following therapeutic abortion/stillbirth (n = 24) or in urine of neonates within the first 2 weeks of life (n = 33), 57 were congenitally infected. In women with proven or suspected primary infection, the intrauterine transmission rates were 20.6% (7/34) and 24.4% (10/41), respectively. Of the congenitally infected live-born infants, 57.6% (19/33) had symptoms of varying degree. The overall sensitivity of PD in the serologic and ultrasound risk groups was 89.5% (51/57). A sensitivity of 100% was achieved by combining detection of CMV-DNA and CMV-specific IgM in fetal blood or by combined testing of AF and fetal blood for CMV-DNA or IgM antibodies. There was no instance of intrauterine death following the invasive procedure. The predictive value of PD for fetal infection was 95.7% (132/138) for negative results and 100% (51/51) for positive results. Correct results for congenital CMV infection by testing AF samples can be expected with samples obtained after WG 21 and after a time interval of at least 6 weeks between first diagnosis of maternal infection and PD. In case of negative findings in AF or fetal blood and the absence of ultrasound abnormalities at WG 22-23, fetal infection and neonatal disease could be excluded with high confidence. Positive findings for CMV infection in AF and/or fetal blood in combination with CMV suspicious ultrasound abnormalities predicted a high risk of cytomegalic inclusion disease (CID). Furthermore, detection of specific IgM antibodies in fetal blood was significantly correlated with severe outcome for the fetus or the newborn (p = 0.0224). However, normal ultrasound of infected fetuses at WG 22-23 can neither completely exclude an abnormal ultrasound at a later WG and the birth of a severely damaged child nor the birth of neonates which are afflicted by single manifestations at birth or later and of the kind which are not detectable by currently available ultrasonographic techniques.

Multi-system cytomegalovirus fetopathy by recurrent infection in a pregnant woman with hepatitis B

A pregnant woman with acute hepatitis B virus (HBV) infection had her second pregnancy terminated at 25 weeks' gestation because of fetal ascites and ventriculitis. Meconium peritonitis was also found at autopsy. No HBV DNA but cytomegalovirus (CMV) DNA was detected in the fetal liver and ascitic fluid. Recurrent maternal CMV infection was demonstrated by pre-existing CMV IgG antibodies, high IgG avidity and low IgM levels. After abortion, the patient developed chronic active hepatitis. Nevertheless, having become pregnant again with a new partner, she had an uneventful third pregnancy and gave birth to a healthy boy.

Ultrasound and fetal diagnosis of perinatal infection

Prenatal ultrasound can aid the clinician in evaluation of the patient with a suspected in utero TORCH infection, particularly toxoplasmosis, syphilis, and CMV. Demonstration of characteristic ultrasound findings in the high risk patient has a high predictive value for fetal infection and also may have prognostic significance. The sonologist should understand the limitations of ultrasound, discuss them with the patient, and document the discussion in the medical record. Patients should be counseled that ultrasound is not a sensitive test for fetal infection and that a normal fetal anatomy survey cannot predict a favorable outcome. In the low-risk patient, fetal infection should be considered when multiple organ system anomalies, fetal growth restriction, placental enlargement, or abnormalities of amniotic fluid volume are demonstrated.