Antenatal imaging and clinical outcome in congenital CMV infection: A field-wide systematic review and meta-analysis

Counseling in fetal medicine: Congenital cytomegalovirus infection

Although the clinical work-up of CMV in pregnancy has gradually become more accurate, counseling for CMV is still challenging. Despite the potential feasibility of universal prenatal serological screening, its introduction in prenatal diagnosis continues to raise concerns related to its real cost-effectiveness. Contextually, anticipating the confirmation of fetal infection earlier in pregnancy is one of the most pressing issues to reduce the parental psychological burden. Amniocentesis is still the gold standard and recent data have demonstrated that it could be performed before 20 weeks of gestation, provided that at least 8 weeks have elapsed from the presumed date of maternal seroconversion. New approaches, such as chorionic villus sampling (CVS) and virome DNA, even if not yet validated as confirmation of fetal infection, have been studied alternatively to amniocentesis to reduce the time-interval from maternal seroconversion and the amniocentesis results. Risk stratification for sensorineural hearing loss (SNHL) and long-term sequelae should be provided according to the prognostic predictors. Nevertheless, in the era of valacyclovir, maternal high-dose therapy, mainly for first trimester infections, can reduce the risk of vertical transmission and increase the likelihood of asymptomatic newborns, but it is still unclear whether valacyclovir continues to exert a beneficial effect on fetuses with positive amniocentesis. This review provides updated evidence-based key counseling points with GRADE recommendations.

Cytomegalovirus and Pregnancy: A Narrative Review

Cytomegalovirus (CMV) infection is the most common congenital infection worldwide, affecting between 0.7% and 1% of all live births. Approximately 11% of infected newborns are symptomatic at birth, and between 30% and 40% of these are at risk of developing long-term neurological sequelae. Until recently, the lack of an effective treatment did not justify universal testing of pregnant women. In recent years, however, valacyclovir at a dose of 8 g/day has been shown to be effective in preventing vertical transmission, and ganciclovir has been shown to be effective in preventing long-term sequelae in the treatment of symptomatic neonates. The aim of this article is to review congenital CMV infection, from its epidemiology to its treatment, using the most recent studies in the literature, and to help in the decision to modify protocols for universal testing of pregnant women according to the possibilities of each locality.

Fetal brain imaging provides valuable information in cCMV infected infants

BACKGROUND

Congenital CMV infection (cCMV) is the most common congenital infection with 10-15% of cases developing symptomatic disease. Early antiviral treatment is of essence when symptomatic disease is suspected. Recently, the use of neonatal imaging has been implicated as a prognostic tool for long term sequalae among asymptomatic newborns at high risk. Even though neonatal MRI is commonly used in neonatal symptomatic cCMV disease, it is less often used in asymptomatic newborns, mainly due to cost, access and difficulty to perform. We have therefore developed an interest in assessing the use of fetal imaging as an alternative. Our primary aim was to compare the fetal and neonatal MRIs in a small cohort 10 asymptomatic neonates with congenital CMV infection.

METHODS

We performed a single-center retrospective cohort study (case-series) on a convenience sample of children born from January 2014 to March 2021 with confirmed congenital CMV infection who had undergone both fetal and neonatal MRIs. We created a checklist of relevant cerebral abnormalities and asked 4 blinded radiologists to assess the MRIs (2 for each, namely fetal and neonatal) and then compared the findings between the fetal and neonatal imaging as well as the concordance in reporting of abnormalities within each category.

FINDINGS

Overall concordance between prenatal and postnatal scans was high (70%). When comparing the two blinded reports for each MRI, we found high levels of concordance: 90% concordance for fetal MRIs and 100% for neonatal MRIs. The most common abnormalities identified in both fetal and neonatal scans were "abnormal white matter hyperintensity" and "subependymal cysts."

INTERPRETATION

Even though this is a small descriptive study, it indicates that fetal MRI could potentially provide us with similar information as neonatal imaging. This study could form the basis for subsequent larger future studies.

Cost-effectiveness of screening and valacyclovir-based treatment strategies for first-trimester cytomegalovirus primary infection in pregnant women in France

OBJECTIVE

To assess the effectiveness, cost and cost-effectiveness of four screening strategies for first-trimester (T1) cytomegalovirus (CMV) primary infection (PI) in pregnant women in France.

METHODS

In a simulated pregnant population of 800 000 (approximate number of pregnancies each year in France), using costs based on the year 2022, we compared four CMV maternal screening strategies: Strategy S1, no systematic screening (current public health recommendations in France); Strategy S2, screening of 25-50% of the pregnant population (current screening practice in France); Strategy S3, universal screening (current medical recommendations in France); Strategy S4, universal screening (as in Strategy S3) in conjunction with valacyclovir in case of T1 PI. Outcomes were total cost, effectiveness (number of congenital infections, number of diagnosed infections) and incremental cost-effectiveness ratio (ICER). Two ICERs were calculated, comparing Strategies S1, S2 and S3 in terms of euros (€) per additional diagnosis, and comparing Strategies S1 and S4 in € per avoided congenital infection.

RESULTS

Compared with Strategy S1, Strategy S3 enabled diagnosis of 536 more infected fetuses and Strategy S4 prevented 375 congenital infections. Strategy S1 was the least expensive strategy (€98.3m total lifetime cost), followed by Strategy S4 (€98.6m), Strategy S2 (€106.0m) and Strategy S3 (€118.9m). In the first analysis, Strategy S2 was dominated and Strategy S3 led to an additional €38 552 per additional in-utero diagnosis, compared with Strategy S1. In the second analysis, Strategy S4 led to an additional €893 per avoided congenital infection compared with Strategy S1, and was cost-saving compared with Strategy S2.

CONCLUSIONS

In France, current screening practice for CMV PI during pregnancy is no longer acceptable in terms of cost-effectiveness because this strategy was dominated by universal screening. Moreover, universal screening in conjunction with valacyclovir treatment would be cost-effective compared with current recommendations and is cost-saving compared with current practice. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Neurodevelopmental outcomes in congenital and perinatal infections

PURPOSE OF REVIEW

Congenital infections are a major cause of childhood multidomain neurodevelopmental disabilities. They contribute to a range of structural brain abnormalities that can cause severe neurodevelopmental impairment, cerebral palsy, epilepsy, and neurosensory impairments. New congenital infections and global viral pandemics have emerged, with some affecting the developing brain and causing neurodevelopmental concerns. This review aims to provide current understanding of fetal infections and their impact on neurodevelopment.

RECENT FINDINGS

There are a growing list of congenital infections causing neurodevelopmental issues, including cytomegalovirus, Zika virus, syphilis, rubella, lymphocytic choriomeningitis virus, and toxoplasmosis. Fetal exposure to maternal SARS-CoV-2 may also pose risk to the developing brain and impact neurodevelopmental outcomes, although studies have conflicting results. As Zika virus was a recently identified congenital infection, there are several new reports on child neurodevelopment in the Caribbean and Central and South America. For many congenital infections, children with in-utero exposure, even if asymptomatic at birth, may have neurodevelopmental concerns manifest over time.

SUMMARY

Congenital infections should be considered in the differential diagnosis of a child with neurodevelopmental impairments. Detailed pregnancy history, exposure risk, and testing should guide diagnosis and multidisciplinary evaluation. Children with congenital infections should have long-term follow-up to assess for neurodevelopmental delays and other neurosensory impairments. Children with confirmed delays or high-risk should be referred for rehabilitation therapies.

Ultrasonographic Signs of Cytomegalovirus Infection in the Fetus-A Systematic Review of the Literature

BACKGROUND

congenital cytomegalovirus (cCMV) infection during pregnancy is a significant risk factor for fetal and neonatal morbidity and mortality. CMV detection is based on the traditional ultrasound (US) and MRI (magnetic resonance) approach.

METHODS

the present review used the PRISMA protocol for identification of studies associated with CMV infection and sonographic analysis. Various search terms were created using keywords which were used to identify references from Medline, Pubmed, PsycInfo, Scopus and Web of Science.

RESULTS

sonographic analysis of the cCMV infection identified several of the key features associated with fetuses. The presence of abnormal patterns of periventricular echogenicity, ventriculomegaly and intraparenchymal calcifications is indicative of CMV infection in the fetus. Hyperechogenic bowels were seen frequently. These results correlate well with MRI data, especially when targeted transvaginal fetal neurosonography was carried out.

CONCLUSIONS

ultrasonography is a reliable indicator of fetal anomalies, due to cCMV. Fetal brain and organ changes are conclusive indications of infection, but many of the ultrasonographic signs of fetal abnormality could be due to any viral infections; thus, further research is needed to demarcate CMV infection from others, based on the ultrasonographic approach. CMV infection should always be an indication for targeted fetal neurosonography, optimally by the transvaginal approach.

Anatomical and diffusion-weighted imaging of brain abnormalities in third-trimester fetuses with cytomegalovirus infection

OBJECTIVES

In this study of cytomegalovirus (CMV)-infected fetuses with first-trimester seroconversion, we aimed to evaluate the detection of brain abnormalities using magnetic resonance imaging (MRI) and neurosonography (NSG) in the third trimester, and compare the grading systems of the two modalities. We also evaluated the feasibility of routine use of diffusion-weighted imaging (DWI) fetal MRI and compared the regional apparent diffusion coefficient (ADC) values between CMV-infected fetuses and presumed normal, non-infected fetuses in the third trimester.

METHODS

This was a retrospective review of MRI and NSG scans in fetuses with confirmed first-trimester CMV infection performed between September 2015 and August 2019. Brain abnormalities were recorded and graded using fetal MRI and NSG grading systems to compare the two modalities. To investigate feasibility of DWI, a four-point rating scale (poor, suboptimal, good, excellent) was applied to assess the quality of the images. Quantitative assessment was performed by placing a freehand drawn region of interest in the white matter of the frontal, parietal, temporal and occipital lobes and the basal ganglia, pons and cerebellum to calculate ADC values. Regional ADC measurements were obtained similarly in a control group of fetuses with negative maternal CMV serology in the first trimester, normal brain findings on fetal MRI and normal genetic testing.

RESULTS

Fifty-three MRI examinations of 46 fetuses with confirmed first-trimester CMV infection were included. NSG detected 24 of 27 temporal cysts seen on MRI scans, with a sensitivity of 78% and an accuracy of 83%. NSG did not detect abnormal gyration visible on two (4%) MRI scans. Periventricular calcifications were detected on two MRI scans compared with 10 NSG scans. While lenticulostriate vasculopathy was detected on 11 (21%) NSG scans, no fetus demonstrated this finding on MRI. MRI grading correlated significantly with NSG grading of brain abnormalities (P < 0.0001). Eight (15%) of the DWI scans in the CMV cohort were excluded from further analysis because of insufficient quality. The ADC values of CMV-infected fetuses were significantly increased in the frontal (both sides, P < 0.0001), temporal (both sides, P < 0.0001), parietal (left side, P = 0.0378 and right side, P = 0.0014) and occipital (left side, P = 0.0002 and right side, P < 0.0001) lobes and decreased in the pons (P = 0.0085) when compared with non-infected fetuses. The ADC values in the basal ganglia and the cerebellum were not significantly different in CMV-infected fetuses compared with normal controls (all P > 0.05). Temporal and frontal ADC values were higher in CMV-infected fetuses with more severe brain abnormalities compared to fetuses with mild abnormalities.

CONCLUSIONS

Ultrasound and MRI are complementary during the third trimester in the assessment of brain abnormalities in CMV-infected fetuses, with a significant correlation between the grading systems of the two modalities. On DWI in the third trimester, the ADC values in several brain regions are abnormal in CMV-infected fetuses compared with normal controls. Furthermore, they seem to correlate in the temporal area and, to a lesser extent, frontal area with the severity of brain abnormalities associated with CMV infection. Larger prospective studies are needed for further investigation of the microscopic nature of diffusion abnormalities and correlation of different imaging findings with postnatal outcome. © 2022 International Society of Ultrasound in Obstetrics and Gynecology.

The Role of Fetal Brain Magnetic Resonance Imaging in Current Fetal Medicine

In open spina bifida we studied the use of MRI for the assessment of the posterior fossa and prevalence of supratentorial anomalies before and after in utero repair. New postprocessing techniques were applied to evaluate fetal brain development in this population compared to controls. In fetuses with congenital diaphragmatic hernia, we evaluated the brain development in comparison to controls. Diffusion weighted imaging was applied to study difference between fetuses with proven first trimester cytomegalovirus infection and controls. Finally, we investigated the value of third trimester fetal brain MRI after treatment for complicated monochorionic diamniotic pregnancies.