Early detection by magnetic resonance imaging of fetal cerebral damage in a fetus with hydrops and cytomegalovirus infection

The association between maternal cytomegalovirus urinary excretion and congenital infection rate

Background

In utero Cytomegalovirus (CMV) vertical transmission occurs predominantly during primary maternal infection. There are no known non-invasive methods for diagnosis of fetal infection before delivery, however some risk factors have been suggested. We aimed to evaluate the association between maternal CMV urinary excretion and congenital CMV infection.

Methods

A retrospective cohort study of all women who were diagnosed with primary CMV infection during pregnancy in a single university affiliated tertiary medical center, between 2012 and 2016. We examined congenital CMV infection and disease rates among infants born to women with and without CMV urinary excretion.

Results

Overall, 126 women were included, 77 in the positive urinary excretion group, and 49 in the negative urinary excretion group. There was no difference in maternal symptoms between the groups. We found no difference in congenital CMV infection and disease rates between infants born to women with and without urinary excretion of CMV (congenital infection rate 37.1% vs. 24.4%, p = 0.209, congenital disease rate of 18.2% vs. 22.4%, p = 0.648). Women with positive urinary CMV excretion had lower IgG avidity values (36.7% vs 54.6%, p = 0.007), with no additional difference in serology pattern. Compared to asymptomatic women, those with CMV related symptoms did not have significantly higher rates of urinary excretion of CMV (70% vs. 60.5%, p = 0.38) or congenital infection rates (40.7% vs. 31.2%, p = 0.48).

Conclusion

Among infants of women with primary CMV infection in pregnancy, we did not find an association between urinary excretion of CMV and congenital CMV infection.

Timing of MRI in pregnancy, repeat exams, access, and physician qualifications

This review addresses specific questions regarding performance and utility of fetal MR. The specific issues addressed are (1) physician qualifications; (2) MR safety; (3) access to fetal MR; (4) timing of MRI in pregnancy; (5) repeat exams; and (6) when MRI is most effective for prenatal diagnosis. Fetal MRI is a problem-solving tool used for specific indications that are driven by ultrasound or at times by family history. Fetal MR should always be performed with knowledge of the sonographic findings from prior targeted scan. The best evidence for utility of MR is in assessment of CNS anomalies and assessment of the fetus with airway obstruction requiring decisions regarding mode of therapy. The type of information provided by MR can profoundly impact patient counseling and management. We recommend a team approach including specialists in obstetric imaging, fetal MRI, and postnatal care in interpreting MR so that the best information can be given to the pregnant patient.

Management of pregnancies with confirmed cytomegalovirus fetal infection

Systematic screening for cytomegalovirus (CMV) maternal infection is not recommended in most countries. Nevertheless, primary CMV infection will occur in around 1% of women. The vertical transmission rate is estimated to be around 30-50%. Newborns with congenital CMV infection remain asymptomatic in the majority of cases and around 10% will present with a wide range of abnormalities. Fetal infection can be diagnosed by amniocentesis with amplification of the viral genome in the amniotic fluid by polymerase chain reaction. This prenatal diagnosis is mainly performed when ultrasound abnormalities are observed. The purpose of this mini-review is to describe the management options when a fetus is known to be infected.

Brain magnetic resonance findings in symptomatic congenital cytomegalovirus infection

BACKGROUND

Congenital cytomegalovirus (CMV) infection can lead to severe neurological sequelae, but a defined brain magnetic resonance (MR) pattern and MR predictors of clinical outcome are still lacking.

MATERIALS AND METHODS

Clinical and MR findings of 14 children with symptomatic congenital CMV infection were retrospectively reviewed.

RESULTS

Microcephaly, cerebral palsy and epilepsy were found in eight, six and seven patients, respectively (all concomitant in 6); 12 children developed sensory-neural hearing loss (SNHL). At first MRI (mean age 21 months, range 5-54 months), white matter (WM) involvement was not assessable in two children due to incomplete myelination. WM abnormalities were common (11/12 patients); deep WM was predominantly involved in 5/11; the largest WM lesion was in the parietal lobe in 6/11. Anterior temporal lobe abnormalities were found in 13/14. Six children underwent MRI examination after 2 years of life; in this subgroup, WM abnormalities were extensive and confluent (4/6), bilateral and multifocal (1/6) or absent (1/6). Four children showed a progression of myelination. Ventriculomegaly (9/14), migration disorders (6/14 polymicrogyria and 1/14 pachygyria-lissencephaly) and hippocampal dysplasia (6/14) correlated with severe neurological sequelae (p < 0.05, Fisher exact test), while the presence of WM abnormalities (11/12), periventricular cysts (6/14) and cerebellar hypoplasia (4/14) did not predict the outcome.

CONCLUSIONS

The spectrum of brain MR abnormalities in symptomatic congenital CMV infection is extremely wide. WM involvement is variable, difficult to evaluate at a very young age and unrelated to clinical outcome, while cortical malformations, ventriculomegaly and hippocampal dysplasia seem to be strong predictors of poor outcome except for SNHL.

Value of prenatal ultrasound and magnetic resonance imaging in assessment of congenital primary cytomegalovirus infection

OBJECTIVE

To evaluate the outcome of pregnancies with proven and well-dated primary cytomegalovirus (CMV) infection with and without abnormal fetal ultrasound and magnetic resonance imaging (MRI) findings.

METHODS

This was a prospective study of 38 singleton pregnancies with proven vertical transmission of CMV and prenatal ultrasound and MRI examinations. Entry requirements included precise dating of the pregnancy and known time of maternal infection. Neonatal follow-up was a strict requirement, all neonates having eye fundus examination, a brain ultrasound scan and a hearing evaluation. All children were followed up by specialists in child development.

RESULTS

Primary CMV infection occurred during the first trimester in 10 patients, the second trimester in 19 and the third trimester in nine. Twenty-four of 29 patients with first- or second-trimester infections delivered; the other five underwent termination of pregnancy (TOP). Three patients had abnormal sonographic findings with normal MRI. Of these, two had damage to the auditory system. In both cases, infection occurred during the first trimester. In 16 patients with first- or second-trimester infection, both ultrasound and MRI exams were normal; there was one TOP but all other cases had favorable outcome, with normal hearing and developmental evaluations. The outcome of five pregnancies with subtle MRI findings and normal ultrasound exam was also favorable. None of the children infected during the third trimester was affected.

CONCLUSION

The outcome of congenital primary CMV infection with normal prenatal ultrasound and MRI exams is favorable. The prognostic value of subtle MRI findings is limited and when such findings are isolated, termination of pregnancy is unlikely to be justified.