In utero treatment of congenital cytomegalovirus infection with valacyclovir in a multicenter, open-label, phase II study

Congenital Cytomegalovirus Infection: Update on Screening, Diagnosis and Treatment: Scientific Impact Paper No. 56

Cytomegalovirus (CMV) is the most common cause of viral infection in newborn babies, and affects 1 in 200 of all live born infants in high-income countries; and 1 in 71 in low- and middle-income countries. It is a major cause of hearing loss and brain damage. Women may get CMV infection for the first time during pregnancy (primary infection) or may experience 'non-primary' infection, either by reactivation of previous CMV infection or by a new infection with a different strain of the virus. The most common source of infection to pregnant women is the saliva and urine of young children. Therefore, all pregnant women, especially those in regular contact with young children, should be informed about hygiene-based measures to reduce the risks, e.g. handwashing. The UK National Screening Committee recommends against universal antenatal or newborn screening for CMV. Testing for CMV is usually offered only to women who develop symptoms of influenza, glandular fever or hepatitis (liver inflammation) during pregnancy, or for those whom a routine ultrasound scan detects fetal anomalies that suggests possible CMV infection. The risk of harm to the fetus is greatest following primary CMV infection of the woman in early pregnancy, and appears to be very low following infection after 12 weeks of pregnancy. Babies with CMV infection at birth may have jaundice, a rash, enlarged liver or spleen, a small brain, or be small for their gestational age. Around 1 in 8 babies born with CMV infection will have clinically detectable signs at birth. The rest will not have any features detectable by clinical examination alone. Therefore, all infants with CMV infection at birth should be followed up at a minimum of up to 2 years of age or later, depending upon the disease status, to check hearing and brain development. Following primary CMV infection in the first 12 weeks of pregnancy, if the woman starts taking the antiviral medicine valaciclovir (valacyclovir) it reduces the risk of the baby becoming infected. Where CMV infection of the fetus in the womb has been confirmed (by amniocentesis, for example), regular ultrasound scans should be offered every 2-3 weeks until birth. Detailed assessment of the fetal brain is an essential part of these scans. Where maternal CMV infection occurs, but fetal infection is not confirmed, repeated ultrasound scans of the fetus should be offered every 2-3 weeks until birth. In infected fetuses, as well as ultrasound scans, an MRI scan of the brain should be offered at 28-32 weeks of gestation (and sometimes repeated 3-4 weeks later) to assess for any signs of harm to the fetal brain. All babies born to women with confirmed or suspected CMV infection should be tested for CMV with a urine or saliva sample within the first 21 days of life. In newborns with symptomatic CMV infection at birth, treatment with antiviral medicine (valganciclovir or ganciclovir) can reduce hearing loss in 5 out of 6 babies, and improve long-term brain development outcomes in some. There is no licensed vaccine for CMV.

Severe Cytomegalovirus Congenital Infection With Neurological Compromise a Case Series Study in Mexico: Severe CMV and Neurological Compromise

Four cases of serious congenital cytomegalovirus (CMV) infections are described in this report. All cases were diagnosed postnatally using cerebrospinal fluid (3/4) or blood PCR (1/4) and histochemical study of the placenta (4/4). All infants were born prematurely. Maternal factors identified as significant were younger age at pregnancy and those from low-income social strata. The major clinical findings among patients with congenital CMV infection were hydrocephalus and persistent thrombocytopenia. The children's clinical condition did not improve over the course of the disease, leading to complications associated with extreme prematurity. Two of the children died, one of whom had severe brain malformations and showed neurological compromise at follow-up, seizures, motor impairment, and severe cognitive delay. It is essential to perform antenatal screening for possible CMV infection among pregnant women, even in countries with high population seropositivity, such as Mexico, to establish prenatal interventions to reduce the risk of fetal damage.

Prenatal and postnatal antiviral therapies for the prevention and treatment of congenital cytomegalovirus infections

PURPOSE OF REVIEW

Congenital cytomegalovirus infection (cCMV) is the leading infectious cause of sensorineural hearing loss and lifelong neurodevelopmental disabilities. Studies suggest antiviral therapy can prevent fetal infection after maternal primary infection, as well as halt the progression of hearing loss and neurodevelopmental disabilities in newborns with symptomatic cCMV. With growing worldwide momentum on early detection and diagnosis of cCMV, this review describes the exciting recent advances in antiviral therapies in CMV infected pregnant mothers and babies, as well as emerging evidence on anti-CMV vaccines.

RECENT FINDINGS

New opportunities for prenatal and neonatal interventions have driven a rising interest in screening and identification of asymptomatic CMV infection. Routine screening of pregnant women to identify primary infection in first trimester is now advocated in Western Europe but has yet to be examined from a public health perspective in other regions. Evidence is emerging for maternal valaciclovir therapy to prevent fetal infection after a maternal primary CMV infection in the first trimester of pregnancy. For those infants who are born with symptomatic cCMV, a 6-month course of valganciclovir, started within the first 4 weeks of life, and possibly up to 13 weeks of life, is the current recommended therapy. However, there is unclear evidence for the benefit of treatment for asymptomatic cCMV and cCMV with isolated hearing loss. Research to identify more effective antivirals and an effective CMV vaccine continues.

SUMMARY

More research is needed to determine the region-specific applicability of the new European recommendations for routine CMV screening in pregnancy. Areas of uncertainty in postnatal management include timing of initiation, duration of treatment and identifying pediatric subgroups that benefit from modification of the standard treatment recommendations.

Inhibition of human cytomegalovirus entry into mucosal epithelial cells

Human cytomegalovirus (CMV) causes serious developmental disabilities in newborns infected in utero following oral acquisition by the mother. Thus, neutralizing antibodies in maternal saliva have potential to prevent maternal infection and, consequently, fetal transmission and disease. Based on standard cell culture models, CMV entry mediators (and hence neutralizing targets) are cell type-dependent: entry into fibroblasts requires glycoprotein B (gB) and a trimeric complex (TC) of glycoproteins H, L, and O, whereas endothelial and epithelial cell entry additionally requires a pentameric complex (PC) of glycoproteins H and L with UL128, UL130, and UL131A. However, as the mediators of mucosal cell entry and the potential impact of cellular differentiation remained unclear, the present studies utilized mutant viruses, neutralizing antibodies, and soluble TC-receptor to determine the entry mediators required for infection of mucocutaneus cell lines and primary tonsil epithelial cells. Entry into undifferentiated cells was largely PC-dependent, but PC-independent entry could be induced by differentiation. TC-independent entry was also observed and varied by cell line and differentiation. Infection of primary tonsil cells from some donors was entirely TC-independent. In contrast, an antibody to gB or disruption of virion attachment using heparin blocked entry into all cells. These findings indicate that CMV entry into the spectrum of cell types encountered in vivo is likely to be more complex than has been suggested by standard cell culture models and may be influenced by the relative abundance of virion envelope glycoprotein complexes as well as by cell type, tissue of origin, and state of differentiation.

In utero treatment of congenital cytomegalovirus infection with valganciclovir: an observational study on safety and effectiveness

BACKGROUND

The treatment of congenital cytomegalovirus (CMV) infection is usually administered to neonates after birth; however, it can be anticipated during the prenatal period by treating pregnant women in order to reduce the severity of the congenital disease. The most commonly used treatment for CMV during pregnancy is valaciclovir; however, valganciclovir has a higher potency against CMV and is the first choice for neonates with congenital CMV disease.

OBJECTIVES

We investigated neonatal and maternal safety of tertiary prevention in infected fetuses showing ultrasound features of infection using valganciclovir.

METHODS

Retrospective cohort study of pregnant women and their symptomatic infected fetuses taking valganciclovir, 3 × 450 mg per day. All fetuses presented at least one prenatal feature on ultrasound. We assessed fetal/neonatal and maternal safety, as well as neonatal efficacy of treatment. The main outcome was neutropenia. Secondary outcomes included other haematological side effects, symptoms at birth and neonatal CMV-PCR was positive.

RESULTS

Seventeen women with singleton pregnancies received valganciclovir from a median (IQR) of 27.1 (26.0-30.3) to 11.6 (6.5-12.9) weeks of gestation. No neonatal neutropenia was reported. One pregnancy was terminated for severe features. Three newborns (18%) were asymptomatic at birth, including one with negative CMV-PCR from blood and saliva. CMV-PCR was positive for 12/13 symptomatic newborns, with a median (IQR) log10 viral load of 3.36 (3.30-4.20), 4.03 (1.75-4.27) and 3.04 (0.00-3.40) log10 copies/mL in blood, urine and saliva, respectively.

CONCLUSIONS

Tertiary prevention by valganciclovir appears to be well tolerated for both fetus and mother. However, more extensive trials accompanied by long-term follow-up are needed.

Cytomegalovirus congenital infection: long-term outcomes in a valaciclovir treated population

OBJECTIVES

This case series aims to evaluate the long-term outcomes of congenital cytomegalovirus (CMV) infection in a population treated with valaciclovir during pregnancy. The study focuses on assessing the prevalence of long-term sequelae in infants with confirmed CMV fetal infection.

METHODS

A retrospective analysis was conducted on 33 pregnancies corresponding to 34 fetus with confirmed CMV congenital infection. They were followed from November 2004 to December 2020. Valaciclovir treatment was initiated after confirmation of fetal infection, and fetal outcomes were monitored through serial ultrasounds, neurosonography, and fetal magnetic resonance imaging (MRI). Postnatal assessments included: PCR confirmation, symptoms evaluation at birth, and long-term follow-up protocols for visual, auditory, and neurodevelopmental assessment.

RESULTS

Therapy was started at a median gestational age of 24 weeks. Of the 34 newborns 79.4 % were asymptomatic at birth. Median follow-up time was 6 years and 32.35 % developed long-term sequelae. Neurosensorial hearing loss (SNHL) was the predominant sequelae. In the cases which developed sequelae 54.5 % had imaging findings, and all with major findings developed long-term sequelae.

CONCLUSIONS

In our treated population we had a higher asymptomatic rate at birth comparing with a non-treated population, similar to those found in previous studies. We had a long-term sequelae rate of 32.35 %, similar to recent studies on non-treated population, although we registered a slightly lower rate of SNHL. A larger multicenter studies with a longer follow-up time, where treatment is started in the first trimester, is of the utmost importance, so we can truly understand the correlation between these imaging findings, therapy and long-term sequelae.

Cytomegalovirus-Specific Hyperimmune Immunoglobulin Administration for Secondary Prevention after First-Trimester Maternal Primary Infection: A 13-Year Single-Center Cohort Study

Primary cytomegalovirus infection during pregnancy has a high risk of vertical transmission, with severe fetal sequelae mainly associated with first-trimester infections. We conducted a retrospective analysis of 200 IU/kg cytomegalovirus-specific hyperimmune globulin (HIG), used in first-trimester maternal primary infections for congenital infection prevention. The primary outcome was vertical transmission, defined as neonatal viruria or positive amniocentesis if pregnancy was discontinued. HIG, initially administered monthly and since 2019 biweekly, was discontinued in negative amniocentesis cases. Women declining amniocentesis and positive amniocentesis cases with normal sonography were offered monthly HIG until delivery as a treatment strategy. The total transmission rate was 29.9% (32/107; 10 pregnancy terminations with positive amniocentesis, 18 completed pregnancies with positive amniocentesis and 4 declining amniocentesis). Maternal viremia was the only factor associated with fetal transmission (OR 4.62, 95% CI 1.55-13.74). The transmission rate was not significantly different whether HIG was started during the first or second trimester (28.2% vs. 33.3%; p = 0.58), or between monthly and biweekly subgroups (25.7% vs. 37.8%, p = 0.193). Pre-treatment maternal viremia could inform decisions as a predictor of congenital infection.

Safety and Efficacy of Antiviral Drugs and Vaccines in Pregnant Women: Insights from Physiologically Based Pharmacokinetic Modeling and Integration of Viral Infection Dynamics

Addressing the complexities of managing viral infections during pregnancy is essential for informed medical decision-making. This comprehensive review delves into the management of key viral infections impacting pregnant women, namely Human Immunodeficiency Virus (HIV), Hepatitis B Virus/Hepatitis C Virus (HBV/HCV), Influenza, Cytomegalovirus (CMV), and SARS-CoV-2 (COVID-19). We evaluate the safety and efficacy profiles of antiviral treatments for each infection, while also exploring innovative avenues such as gene vaccines and their potential in mitigating viral threats during pregnancy. Additionally, the review examines strategies to overcome challenges, encompassing prophylactic and therapeutic vaccine research, regulatory considerations, and safety protocols. Utilizing advanced methodologies, including PBPK modeling, machine learning, artificial intelligence, and causal inference, we can amplify our comprehension and decision-making capabilities in this intricate domain. This narrative review aims to shed light on diverse approaches and ongoing advancements, this review aims to foster progress in antiviral therapy for pregnant women, improving maternal and fetal health outcomes.

Congenital Cytomegalovirus-Related Hearing Loss

Congenital hearing loss is a significant global health concern that affects millions of newborns and infants worldwide, posing substantial challenges for affected individuals, their families, and healthcare systems. This condition, present at birth, can stem from genetic factors, in utero exposures, infections, or complications during pregnancy or childbirth. The spectrum of congenital hearing loss ranges from mild to profound, impacting the development of speech, language, and cognitive skills, thereby influencing educational achievements, social integration, and future employment opportunities. Early detection and intervention strategies, such as newborn hearing screenings, genetic counseling, and the use of hearing aids or cochlear implants, are crucial for mitigating these impacts. This review article aims to explore the diagnostic approaches and management strategies for congenital cytomegalovirus-related hearing loss, emphasizing the importance of interdisciplinary care and the potential for technological advances to improve outcomes for affected individuals.

Ophthalmic Complications, Diagnosis, and Treatment of Congenital Human Cytomegalovirus Infection

Background: Human cytomegalovirus (hCMV) is the most common etiological agent of congenital infections seen in newborns. Among the most commonly observed complications in children with congenital human cytomegalovirus infection are those affecting the visual system. Ocular complications of congenital CMV (cCMV) are a topic rarely addressed in the literature, which prompted the authors to update the available knowledge with the latest data. Methodology: English-language literature published between April 2000 and November 2023 (PubMed, NIH, Google Scholar) was analyzed for ocular complications of cCMV. The data obtained were categorized according to the ocular area involved and the incidence. A compilation of criteria for the symptomatic form of cCMV was also created. Results: The cCMV complications described in the literature affect all parts of the visual system: the anterior segment, the posterior segment, the posterior visual pathways, and the visual cortex. The most commonly described ocular complication of cCMV is choroidal and retinal scarring. Conclusions: Ophthalmic complications of cCMV can cause severe visual disturbances. Ophthalmic diagnosis in newborns should include hCMV PCR testing, which has the highest sensitivity and specificity. In the symptomatic form of cCMV, treatment should be instituted according to recommendations. A consensus should be established for screening of primary hCMV infection in pregnant women, the way in which to define the symptomatic form of cCMV, and the appropriateness and standards of treatment for primary hCMV infection in pregnant women.

Congenital Cytomegalovirus Infection With Isolated "Minor" Lesions at Fetal Magnetic Resonance Imaging: Long-Term Neurological Outcome

BACKGROUND

The prognostic relevance of fetal/early postnatal magnetic resonance (MR) imaging (MRI) isolated "minor" lesions in congenital cytomegalovirus (CMV) infection is still unclear, because of the heterogeneity of previously reported case series. The aim of this study was to report the imaging and long-term clinical follow-up data on a relatively large cohort of infected fetuses.

METHODS

Among 140 CMV-infected fetuses from a single-center 12-year-long fetal MRI database, cases that showed isolated "minor" lesions at MRI, mainly represented by polar temporal lesions, were selected. MRI features were described, and clinical follow-up information was collected through consultation of medical records and telephone interview to establish the auditory and neurological outcome of each patient.

RESULTS

Thirty-six cases were included in the study. The frequency of "minor" lesions increased progressively with ongoing gestational age in cases who underwent serial MR examination; 31% of cases were symptomatic at birth for unilateral altered auditory brainstem response. At long-term clinical follow-up, performed in 35 patients at a mean age of 64.5 months (range: 25 to 138), 43% of patients were asymptomatic and 57% presented with mild/moderate disability including hearing loss (34%), unilateral in all cases but one (therefore classified as severe), and/or minor cognitive and behavioral disorders (49%).

CONCLUSIONS

Descriptive analysis of the type and modality of occurrence of "minor" lesions suggests performing serial fetal/postnatal MR examinations not to miss later-onset lesions. Follow-up data from the present cohort, combined with maternal/fetal factors and serologic-laboratory parameters may contribute to improve prenatal and neonatal period counselling skills.

[Implementation of screening for cytomegalovirus congenital infection in a French type 3 maternity]

OBJECTIVES

Congenital cytomegalovirus (CMV) infection is the most common congenital infection and the leading cause of infectious neurosensorial disability in newborns. We wanted to organize the management of women from the beginning of pregnancy allowing access to antenatal treatment with valaciclovir, recognized since 2020 as limiting materno-fetal transmission. To this end, we set up and evaluated the interest of systematic screening for CMV infection in our maternity. We wanted to organize care for women from the very start of pregnancy.

METHODS

Retrospective and comparative descriptive study carried out at the CHRU de Limoges from July 2017 to December 2019 (targeted screening), then from January 2020 to June 2022, during which period we implemented systematized screening by iterative serologies at the 3rd, 6th, 8th months and before delivery. Our main evaluation criteria were the seroprevalence of CMV infection and the rate of congenital infection. We then described our cases of infection (primary or secondary) during pregnancy.

RESULTS

CMV seroprevalence in our pregnant women increased significantly from 52.7% (779/1478 women screened) to 58.4% (3852/6599 women screened) between the 2 study periods (P=0.04). We diagnosed 11 infections during the first part of the study vs. 27 during the second, with a significant increase in primary infections from 0.14% (9/6524 births) to 0.37% (24/6426 births) (P=0.008). Only 3 secondary infections were diagnosed during the second study period. The rate of congenital infections remained stable between the 2 study periods (6 children/6524=0.09% vs. 8 children/6426=0.12%; P=0.57).

CONCLUSION

Our results confirmed the interest of screening for CMV infection, while modifying the screening strategy we had initiated.

Fetal Cytomegalovirus Infection in the Absence of Maternal Cytomegalovirus-IgM Seropositivity

The aim of this study was to evaluate maternal serological status and fetal sonographic findings of Cytomegalovirus (CMV) infection. This is a retrospective study performed at Perinatology Department of Istanbul Başakşehir Çam and Sakura City Hospital. A computerized search was conducted to identify cases who underwent prenatal diagnosis of fetal CMV infection between September 2020 and December 2023. We identified nine cases with fetal CMV infection. The clinical data of the patients, gestational age at the time of diagnosis, serological, sonographic findings, and pregnancy outcomes were analyzed. A computer search of the database was made for the seroprevalance of CMV-IgM and CMV-IgG in our population. The CMV-IgM and IgG results of the 1235 patients who underwent CMV screening in the first trimester between September 2020 and December 2023 were evaluated. Fetal CMV infection was identified in nine patients. None of the 9 cases showed maternal CMV-IgM positivity. Seven of the 9 patients showed high IgG avidity index. Pregnant population had 98 % positivity for CMV-IgG. The evaluation of serologic tests for CMV is not straightforward in the second and third trimester. IgM and IgG avidity should be interpreted with caution in the second and third trimester. In the presence of ultrasound findings suggesting fetal CMV infection and CMV-IgG positivity, invasive diagnostic tests rather than serological test should be discussed with the patient, and non-primary infections should always be considered to minimize overlooked fetal cytomegalovirus infections and missed antiviral treatment opportunity.

Consensus recommendation for prenatal, neonatal and postnatal management of congenital cytomegalovirus infection from the European congenital infection initiative (ECCI)

Congenital cytomegalovirus (cCMV) infection carries a significant burden with a 0.64% global prevalence and a 17-20% chance of serious long-term effects in children. Since the last guidelines, our understanding, particularly regarding primary maternal infections, has improved. A cCMV guidelines group was convened under the patronage of the European Society of Clinical Virology in April 2023 to refine these insights. The quality and validity of selected studies were assessed for potential biases and the GRADE framework was employed to evaluate quality of evidence across key domains. The resulting recommendations address managing cCMV, spanning prevention to postnatal care. Emphasizing early and accurate maternal diagnosis through serological tests enhances risk management and prevention strategies, including using valaciclovir to prevent vertical transmission. The guidelines also strive to refine personalized postnatal care based on risk assessments, ensuring targeted interventions for affected families.

Congenital infectious encephalopathies from the intrapartum period to postnatal life

Congenital infections are a common but often underrecognized cause of fetal brain abnormalities, as well as fetal-neonatal morbidity and mortality, that should be considered by all healthcare professionals providing neurological care to fetuses and newborns. Maternal infection with various pathogens (cytomegalovirus, Toxoplasmosis, Rubella virus, Parvovirus B19, lymphocytic choriomeningitis virus, syphilis, Zika virus, varicella zoster virus) during pregnancy can be transmitted to the developing fetus, which can cause multisystem dysfunction and destructive or malformative central nervous system lesions. These can be recognized on fetal and neonatal imaging, including ultrasound and MRI. Imaging and clinical features often overlap, but some distinguishing features can help identify specific pathogens and guide subsequent testing strategies. Some pathogens can be specifically treated, and others can be managed with targeted interventions or symptomatic therapy based on expected complications. Neurological and neurodevelopmental complications related to congenital infections vary widely and are likely driven by a combination of pathophysiologic factors, alone or in combination. These include direct invasion of the fetal central nervous system by pathogens, inflammation of the maternal-placental-fetal triad in response to infection, and long-term effects of immunogenic and epigenetic changes in the fetus in response to maternal-fetal infection. Congenital infections and their neurodevelopmental impacts should be seen as an issue of public health policy, given that infection and the associated complications disproportionately affect woman and children from low- and middle-income countries and those with lower socio-economic status in high-income countries. Congenital infections may be preventable and treatable, which can improve long-term neurodevelopmental outcomes in children.

Is a Higher Amniotic Fluid Viral Load Associated with a Greater Risk of Fetal Injury in Congenital Cytomegalovirus Infection-A Systematic Review and Meta-Analysis

Background: Numerous studies have aimed to predict prenatal and neonatal outcomes for pregnancies complicated by congenital cytomegalovirus (CMV). Presently, assessing CMV severity prenatally relies largely on fetal imaging. A controversy exists regarding CMV viral load (VL) and its association with fetal and neonatal sequelae. Objective: To perform a systematic review and meta-analysis investigating the association between CMV DNA VL in amniotic fluid and fetal and neonatal outcomes in pregnancies with congenital CMV. Results: All cohort, case-control and observational studies that compared outcomes of fetuses with congenital CMV and provided information on individual patient CMV VL quantified in copies per milliliter (c/mL) from inception to January 2023 were included, with no geographical or language restrictions. A total of 1251 citations were reviewed with eight studies meeting inclusion criteria and included in meta-analysis. Affected pregnancies had a higher VL in the amniotic fluid compared to those unaffected with a mean difference of 2.2e+7 (range 1.5e+7 to 2.8e+7). In subgroup analysis, the VL was significantly higher in the fetuses, with imaging findings related to CMV compared to asymptomatic fetuses with a mean difference of 4.1e+7 (95% CI 2.8e+7-5.4e+7). However, among babies with congenital CMV, the VL was not significantly different between symptomatic and asymptomatic babies. Conclusions: Amniotic fluid CMV VL is associated with fetal sequalae in congenital CMV, with a higher VL conferring a greater risk for prenatal injury.

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.

Contribution of fetal blood sampling to determining the prognosis of congenital cytomegalovirus infections: a case-cohort study in Switzerland

BACKGROUND

Cytomegalovirus is responsible for the most common congenital infection, affecting 0.5% to 1.0% of live births in Europe. Congenital cytomegalovirus infection can be diagnosed during pregnancy by viral DNA amplification in the amniotic fluid, but the prognosis of fetuses without severe brain abnormalities remains difficult to establish on the basis of prenatal imaging alone.

OBJECTIVE

To identify predictors of moderate to severe symptomatic cytomegalovirus infection among fetal blood parameters and to propose an algorithm on the basis of these parameters and on prenatal imaging that would provide the best positive and negative predictive values.

STUDY DESIGN

Fetal blood sampling at 21-28 weeks gestation was performed in fetuses with congenital cytomegalovirus infection confirmed by amniocentesis after maternal infection in the first-trimester or periconceptional period. We compared the levels of hemoglobin, thrombocytes, γ-glutamyl transpeptidase, aspartate aminotransferase, alanine aminotransferase, β2-microglobulin, immunoglobulins G and M, and cytomegalovirus DNA viral loads in amniotic fluid and fetal blood between those with moderate to severe symptomatic infection and those with asymptomatic to mild infection (median follow-up of 36 months for live births).

RESULTS

Among 58 fetuses included, 25 (43%) had a moderate to severe symptomatic infection: 16 with severe cerebral abnormalities, 5 with multiple signs or symptoms at birth, 2 with bilateral sensorineural hearing loss, and 2 with neurodevelopmental delay. The values of thrombocytes, aspartate aminotransferase, β2 microglobulin, Immunoglobulin M, and cytomegalovirus viral loads differed significantly between fetuses with moderate to severe symptomatic infection and those with asymptomatic to mild infection. The optimal strategy to predict moderate to severe symptomatic infection was to first perform fetal brain imaging, followed by fetal blood sampling with the following cutoffs: thrombocytes <120,000/mL, viremia ≥5 log10/mL, and β2 microglobulin ≥12 mg/L). This recursive algorithm had a negative predictive value of 100% for moderately to severely symptomatic infection.

CONCLUSION

The combination of thrombocytes, β2-microglobulin, and cytomegalovirus viral load in fetal blood can be used for prognosis determination, particularly in cytomegalovirus-infected fetuses without severe brain abnormalities at the time of prenatal diagnosis. Future studies should evaluate whether these parameters remain useful in infected fetuses who have been treated with valacyclovir before fetal blood sampling.

The effect of valacyclovir on secondary prevention of congenital cytomegalovirus infection, following primary maternal infection acquired periconceptionally or in the first trimester of pregnancy. An individual patient data meta-analysis

OBJECTIVE

Recent studies have shown that a dosage of 8 g/d of oral valacyclovir reduces substantially the vertical transmission rate of cytomegalovirus in women with primary cytomegalovirus infection acquired periconceptionally or during the first trimester of pregnancy. This individual patient data meta-analysis aimed to assess the effectiveness and safety of valacyclovir treatment in the secondary prevention of congenital cytomegalovirus infection.

DATA SOURCES

MEDLINE, Scopus, Cochrane Central Register of Controlled Trials, the US registry of clinical trials (www.

CLINICALTRIALS

gov), and gray literature sources were searched from inception to March 2023.

STUDY ELIGIBILITY CRITERIA

Randomized controlled trials and quasi-randomized studies administering 8 g/d of oral valacyclovir in pregnant women with primary cytomegalovirus infection acquired periconceptionally or during the first trimester of pregnancy were included.

METHODS

All corresponding authors of the eligible studies were contacted. Cochrane's Risk of Bias 2 and Risk Of Bias In Non-randomised Studies - of Interventions tools were used for the risk of bias assessment. The result of amniocentesis was the primary outcome of interest. A 1-stage individual patient data meta-analysis was performed, using a generalized linear mixed model, clustered by the different trials. A subgroup analysis was performed, assessing separately the effect of valacyclovir in the periconceptional period and first trimester of pregnancy.

RESULTS

Overall, 3 studies were included in the analysis (n=527 women). Valacyclovir reduced the vertical transmission rate of cytomegalovirus (adjusted odds ratio, 0.34; 95% confidence interval, 0.18-0.61). This reduction was apparent for both periconceptional period (adjusted odds ratio, 0.34; 95% confidence interval, 0.12-0.96) and first-trimester (adjusted odds ratio, 0.35; 95% confidence interval, 0.16-0.76) infections. Moreover, valacyclovir reduced the rate of neonatal infection (adjusted odds ratio, 0.30; 95% confidence interval, 0.19-0.47), in both periconceptional period (adjusted odds ratio, 0.30; 95% confidence interval, 0.14-0.61) and first-trimester (adjusted odds ratio, 0.30; 95% confidence interval, 0.17-0.54) infections. Furthermore, valacyclovir reduced the rate of termination of pregnancy because of cytomegalovirus-associated severe fetal findings (adjusted odds ratio, 0.23; 95% confidence interval, 0.22-0.24). The gestational age at the initiation of treatment has a positive correlation with all outcomes. The overall prevalence of severe side effects was 2.1%.

CONCLUSION

A dosage of 8 g/d of oral valacyclovir reduced the vertical transmission rates of cytomegalovirus following primary maternal infection acquired periconceptionally or in the first trimester of pregnancy, with a low incidence of side effects.

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.

Asymptomatic CMV infection at birth following maternal primary infection despite valacyclovir treatment and a subsequent negative amniocentesis. Case report

Valacyclovir is currently the only pharmacological intervention demonstrated to reduce the risk of vertical CMV congenital infection within a randomized clinical trial in case of primary infection during pregnancy. So far, no data are available on the prognosis of children with congenital CMV infection diagnosed at birth after a negative amniocentesis whose mother were treated with valacyclovir during pregnancy, therefore it is essential to carry out a rigorous neurocognitive follow-up in these children in order to investigate the potential clinical consequence.

Congenital cytomegalovirus infection: the state of the art and future perspectives

Congenital cytomegalovirus (cCMV) infection is the most common congenital infection, with an estimated incidence of approximately one in 200 infants in high-income settings. Approximately one in four children may experience life-long consequences, including sensorineural hearing loss and neurodisability. Knowledge regarding prevention, diagnosis, and treatment increased in the recent years, but some challenges remain. In this review, we tried to summarize the current knowledge on both the obstetrical and pediatric areas, while also highlighting controversial aspects and future perspectives. There is a need to enhance awareness among the general population and pregnant women through specific information programs. Further research is needed to better define the classification of individuals at birth and to have a deeper understanding of the long-term outcomes for so defined children. Finally, the availability of valaciclovir medication throughout pregnancy, where appropriate, has prompted the assessment of a universal serological antenatal screening. It is recommended to establish a dedicated unit for better evaluation and management of both mothers and children.

The Multifaceted Clinical Characteristics of Congenital Cytomegalovirus Infection: From Pregnancy to Long-Term Outcomes

BACKGROUND

The aim of this study was to capture multifaceted clinical characteristics of congenital cytomegalovirus (CMV) infection from diagnosis to treatment using a multidisciplinary approach including obstetrics, pediatrics, pathology, and otorhinolaryngology-head and neck surgery.

METHODS

This is a retrospective study including 30 consecutive cases of congenital CMV infection that were diagnosed at a single tertiary hospital located in Seoul, Korea from January 2009 to December 2020. Congenital CMV infection was defined as a positive result by polymerase chain reaction from urine, saliva or cerebrospinal fluid or positive CMV IgM from neonatal blood sampled within 3 weeks after birth. All cases were analyzed with respect to whole clinical characteristics from diagnosis to treatment of congenital CMV by a multidisciplinary approach including prenatal sonographic findings, maternal immune status regarding CMV infection, detailed placental pathology, neonatal clinical manifestation, auditory brainstem response test, and antiviral treatment (ganciclovir or valganciclovir). Long-term outcomes including developmental delay and hearing loss were also investigated.

RESULTS

The total number of births during the study period in our institution was 19,385, with the prevalence of congenital infection estimated to be 0.15%. Among 30 cases of congenital CMV, the median gestational age at delivery was 32.2 weeks [range, 22.6-40.0] and 66.7% of these infants were delivered preterm at less than 37 weeks. Suspected fetal growth restriction was the most common prenatal ultrasound finding (50%) followed by ventriculomegaly (17.9%) and abnormal placenta (17.9%), defined as thick placenta with calcification. No abnormal findings on ultrasound examination were observed in one-third of births. Maternal CMV serology tests were conducted in only 8 cases, and one case each of positive and equivocal IgM were found. The most common placental pathologic findings were chronic villitis (66.7%) and calcification (63.0%), whereas viral inclusions were identified in only 22.2%. The most common neonatal manifestations were jaundice (58.6%) followed by elevation of aspartate aminotransferase (55.2%) and thrombocytopenia (51.7%). After excluding cases for which long-term outcomes were unavailable due to death (n = 4) or subsequent follow up loss (n = 3), developmental delay was confirmed in 43.5% of infants (10/23), and hearing loss was confirmed in 42.9% (9/21) during the follow-up period. In our cohort, 56.7% (17/30) of neonates were treated for congenital CMV with ganciclovir or valganciclovir.

CONCLUSION

Our data show that prenatal findings including maternal serologic tests and ultrasound have limited ability to detect congenital CMV in Korea. Given that CMV is associated with high rates of developmental delay and hearing loss in infants, there is an urgent need to develop specific strategies for the definite diagnosis of congenital CMV infection during the perinatal period by a multidisciplinary approach to decrease the risks of neurologic impairment and hearing loss through early antiviral treatment.

Prevention of Congenital Cytomegalovirus Infection: Review and Case Series of Valaciclovir versus Hyperimmune Globulin Therapy

Cytomegalovirus (CMV) is the most common cause of congenital infections in developed countries because is capable of infecting the fetus after both primary and recurrent maternal infection, and because the virus may be spread for years through infected children. Moreover, CMV is the most serious congenital infection associated with severe neurological and sensorineural sequelae, which can occur at birth or develop later on. Hygienic measures can prevent CMV transmission, which mainly involve contact with children under 3 years of age and attending a nursery or daycare. In animal and human pregnancies, many observational and controlled studies have shown that CMV-specific hyperimmune globulin (HIG) is safe and can significantly decrease maternal-fetal transmission of CMV infection and, mostly, the occurrence of CMV disease. Recently, valaciclovir at the dosage of 8 g/day was also reported to be capable of decreasing the rates of congenital infection and disease. However, comparing the results of our two recent case series, the infants born to women treated with HIG showed significantly lower rates of CMV DNA positivity in urine (9.7% vs. 75.0%; p < 0.0001) and abnormalities after follow-up (0.0% vs. 41.7%; p < 0.0001). The implementation of CMV screening would enable primary prevention via hygiene counseling, improve the understanding and awareness of congenital CMV infection, and increase the knowledge of the potential efficacy of preventive or therapeutic HIG or antiviral administration.

Cytomegalovirus in Pregnancy

Cytomegalovirus is a pervasive DNA herpesvirus that, while clinically insignificant to an immunocompetent adult host, can cause significant morbidity to a congenitally infected fetus. Although detection is often possible with several common ultrasonographic markers and good diagnostic accuracy using polymerase chain reaction testing of amniotic fluid, there are no proven prenatal prevention or antenatal treatment options. Therefore, universal screening is not currently recommended in pregnancy. Strategies that have been studied in the past include immunoglobulins, antivirals, and the development of a vaccine. In this review, we will further discuss the themes above, along with future direction for prevention and treatment.

Primary, Secondary, and Tertiary Prevention of Congenital Cytomegalovirus Infection

Cytomegalovirus infection is the most common congenital infection, affecting about 1% of births worldwide. Several primary, secondary, and tertiary prevention strategies are already available during the prenatal period to help mitigate the immediate and long-term consequences of this infection. In this review, we aim to present and assess the efficacy of these strategies, including educating pregnant women and women of childbearing age on their knowledge of hygiene measures, development of vaccines, screening for cytomegalovirus infection during pregnancy (systematic versus targeted), prenatal diagnosis and prognostic assessments, and preventive and curative treatments in utero.

An Overview of Antiviral Treatments in Pregnancy

Viral infections pose unique threats to pregnant persons and their infants. As the frequency of epidemics caused by novel pathogens increases, understanding pregnancy-specific considerations for antiviral treatments is critical for obstetric and nonobstetric providers alike. The use of pharmacologic therapeutics in pregnancy, which include antivirals, pathogen-specific antibodies, and vaccines, is limited due to the lack of purposeful, methodologic, pharmacometrics analyses in this special population. Our current understanding regarding dosing, safety, and efficacy stems from our knowledge of potential maternal or neonatal risks, observational data, and rarely clinical trials. In this review, we provide an overview on the use of antivirals during pregnancy.

Neonatal and long-term outcomes of infants with congenital cytomegalovirus infection and negative amniocentesis: systematic review and meta-analysis

OBJECTIVE

Cytomegalovirus (CMV) DNA is detectable in the amniotic fluid collected by amniocentesis in cases in which the fetus has been infected. However, cases of congenital neonatal CMV infection with a negative amniocentesis result have also been reported in the literature. The aim of the present study was to compare pregnancies with a negative amniocentesis result to those with a positive amniocentesis result in terms of incidence of fetal insult and long-term sequelae.

METHODS

Observational studies that included pregnant women with CMV infection who underwent amniocentesis and that reported their results together with neonatal and/or long-term outcomes of the offspring were included. The risk of bias in included studies was assessed using the Newcastle-Ottawa Scale. The rate of severe symptoms at birth, defined as neurological symptoms or multiorgan involvement at birth, and the rate of severe sensorineural hearing loss (SNHL) and/or neurodevelopmental impairment at follow-up were the main outcomes of the study. The secondary outcome was the rate of pregnancy termination due to the presence of CMV-associated central nervous system (CNS) findings or multiorgan involvement on ultrasound/magnetic resonance imaging (MRI).

RESULTS

Seven studies were included in the systematic review and meta-analysis. The pooled false-negative rate of amniocentesis was 8.0% (95% CI, 5.0-13.0%). The pooled rate of severe symptoms at birth was 0.0% (95% CI, 0.0-1.0%; I²  = 0%) in fetuses with a negative amniocentesis result and 22.0% (95% CI, 11.0-38.0%; I²  = 75%) in those with a positive amniocentesis result. The pooled odds ratio (OR) was 0.03 (95% CI, 0.01-0.10; I²  = 0%). The pooled rate of severe SNHL and/or neurodevelopmental impairment at follow-up in fetuses with a negative amniocentesis result was 0.0% (95% CI, 0.0-1.0%; I²  = 0%) and, in those with a positive amniocentesis result, it was 14.0% (95% CI, 7.0-26.0%; I²  = 64%). The pooled OR was 0.04 (95% CI, 0.01-0.14; I²  = 0%). The pooled rate of pregnancy termination due to the presence of CMV-associated CNS findings or multiorgan involvement on ultrasound/MRI was 0.0% (95% CI, 0.0-2.0%; I²  = 0%) in fetuses with a negative amniocentesis result and 20.0% (95% CI, 10.0-36.0%; I²  = 82%) in those with a positive amniocentesis result. The pooled OR was 0.03 (95% CI, 0.01-0.08; I²  = 0%). A subgroup analysis including only pregnancies with primary CMV infection and a sensitivity analysis including only prospective studies were carried out, showing very similar results to those of the main analysis.

CONCLUSION

A negative amniocentesis result in pregnant women with CMV infection ensures lack of fetal insult and long-term sequelae to the child, even if transmission has occurred. © 2022 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

The cost-effectiveness of maternal and neonatal screening for congenital cytomegalovirus infection in Japan

Congenital cytomegalovirus infection is the most common congenital infection. Using a decision tree model, cost-effectiveness of maternal screening with subsequent prenatal valacyclovir treatment and newborn screening with neonatal valganciclovir treatment was evaluated. The incremental cost-effectiveness ratio (ICER) was calculated for (1) universal maternal antibody screening with prenatal valacyclovir treatment compared to targeted newborn screening, and (2) universal newborn screening with postnatal valganciclovir treatment compared to targeted newborn screening. We performed a one-way sensitivity analysis. Compared to targeted newborn screening, the ICERs for universal newborn screening and maternal screening were 2 966 296 Japanese Yen (JPY) (21 188 USD) and 1 026 984 JPY (7336 USD), respectively. In all scenarios in the one-way sensitivity analysis, the ICERs of the maternal screening and the universal newborn screening strategies were less than three gross domestic product per capita compared with the targeted newborn screening strategy. Both maternal and universal newborn screening strategies may be cost-effective than a targeted newborn screening program. The potential utility of the maternal screening with valacyclovir treatment strategy, while potentially cost effective in regions with lower baseline seroprevalence rates, requires further study as the modeling was based on limited evidence.

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.

Managing challenges in congenital CMV: current thinking

Congenital human cytomegalovirus (CMV) infection is the most common congenital infection, affecting around 1 in 200 infants in high-income settings. It can have life-long consequences for up to one in four children, including sensorineural hearing loss and neurodisability. Despite the frequency of congenital CMV and the severity for some children, it is a little-known condition by pregnant women, families and healthcare providers. Timely diagnosis of CMV infection in pregnancy is important to facilitate consideration of treatment with valaciclovir, which may reduce the risk of transmission to the fetus or reduce the severity of the outcomes for infected infants. Recognition of features of congenital CMV is important for neonatologists, paediatricians and audiologists to prompt testing for congenital CMV within the first 21 days of life. Early diagnosis gives the opportunity for valganciclovir treatment, where appropriate, to improve outcomes for affected infants. Further research is urgently needed to inform decisions about antenatal and neonatal screening, long-term outcomes for asymptomatic and symptomatic infants, predictors of these outcomes and optimal treatment for women and infants.

Congenital cytomegalovirus infection diagnostics and management

PURPOSE OF THE REVIEW

Congenital cytomegalovirus infection (cCMV) is the most frequent congenital infection and a leading nongenetic cause of sensorineural hearing loss (SNHL) and brain disease. The purpose of this review is to highlight recent developments in the diagnosis and management of children with cCMV.

RECENT FINDINGS

Progress is being made in the efforts to identify more infants with cCMV, especially those with asymptomatic infection. Largely due to efforts by various advocacy/parent groups, a number of states in the United States and many hospital systems have implemented hearing targeted CMV screening and mandated education of pregnant women about CMV.

SUMMARY

cCMV is an important cause of SNHL and neurologic morbidity worldwide. Early identification of infected children is critical to improve outcomes by providing timely interventions and guidance for long-term follow up. The fact that most infants with cCMV have no abnormal clinical findings, and the need to obtain samples for diagnosis within the first 2-3 weeks of life, makes it challenging to identify a majority of infants with cCMV without universal newborn CMV screening.

Emerging Concepts in Congenital Cytomegalovirus

Over a century of research has focused on improving our understanding of congenital cytomegalovirus (cCMV), yet it remains the most common congenital infection in the United States, affecting 3 to 6 per 1000 live born infants each year. Pregnancies affected by cCMV are at a heightened risk of spontaneous abortion and intrauterine fetal demise. Neonates born with cCMV are also at substantial risk for long-term neurodevelopmental sequelae and disability, including sensorineural hearing loss, even those born without clinically apparent disease. Considerable progress has been made in recent years in study of the epidemiology and transmission of cCMV, developing better diagnostic strategies, implementing newborn screening programs, improving therapeutics, and launching vaccine trials. In this article, we review recent developments in the understanding of the virology and immunobiology of cytomegalovirus. We further discuss how this knowledge informs our understanding of the pathophysiology of cCMV and directs strategies aimed at improving outcomes and quality of life for congenitally infected children. We also provide an update on the epidemiology of cCMV in the United States, evolving scientific understanding of maternal-fetal transmission, enhanced screening approaches, and recognition of neonatal and long-term sequelae. Finally, we review the current landscape of pediatric cCMV research and provide recommendations for novel and high-priority areas for future investigation.

Universal First-Trimester Cytomegalovirus Screening and Valaciclovir Prophylaxis in Pregnant Persons: A Cost-Effectiveness Analysis

BACKGROUND

Recent studies suggest a possible benefit of valaciclovir prophylaxis to prevent vertical transmission after a positive serologic screen for primary maternal cytomegalovirus infection during pregnancy, although its cost-effectiveness remains uncertain.

OBJECTIVE

We sought to determine the circumstances under which universal first-trimester maternal serologic screening for maternal cytomegalovirus infection, with valaciclovir prophylaxis to prevent congenital cytomegalovirus, is cost-effective.

STUDY DESIGN

We performed a decision analysis from the perspective of the pregnant person to assess whether universal maternal screening in the first trimester, with subsequent valaciclovir prophylaxis (8g/day from time of positive serologic screen for primary maternal cytomegalovirus infection through 21 weeks' gestation) for those who are acutely infected, is cost-effective compared to usual care (i.e., no routine serologic screening, but amniocentesis if mid-trimester sonographic findings suggest cytomegalovirus). For baseline estimates, we assumed a 35% risk of congenital cytomegalovirus after primary maternal infection and a 71% risk reduction with valaciclovir. We varied valaciclovir's efficacy to identify whether and at what threshold universal screening would be estimated to be cost-effective, compared to usual care. Monte Carlo analyses were performed. A willingness-to-pay threshold of $100,000/quality-adjusted life year was used to define cost-effectiveness.

RESULTS

Under base-case estimates, first-trimester universal screening and valaciclovir prophylaxis for seropositive pregnant persons with acute cytomegalovirus infection is not cost-effective, with a cost of $137,854 per maternal QALY, but results in 14 fewer cytomegalovirus-affected children per 100,000 pregnancies compared to usual care. In one-way sensitivity analysis, universal screening and treatment is estimated to be the cost-effective strategy if the incidence of primary maternal cytomegalovirus infection exceeds 2.6%, baseline risk of vertical transmission of cytomegalovirus without prophylaxis is greater than 36.8%, and the risk reduction of vertical transmission of cytomegalovirus with valaciclovir prophylaxis exceeds 75.9%. In Monte Carlo analyses, first-trimester universal serologic screening with valaciclovir prophylaxis is estimated to be the cost-effective strategy in 46.8% of runs.

CONCLUSION

Universal first-trimester serologic screening with valaciclovir prophylaxis is not the cost-effective strategy for antenatal management of cytomegalovirus under the base-case estimates. Although universal screening is cost-effective in certain circumstances when the efficacy of valaciclovir exceeds the base case, that result is not robust to variation of estimates across their reasonable ranges. These data can inform future studies to evaluate screening and treatment to prevent congenital CMV.

Describing the impact of maternal hyperimmune globulin and valaciclovir on the outcomes of CMV infection in pregnancy: a systematic review

Cytomegalovirus is the leading infectious cause of congenital neurological disabilities. Valaciclovir and CMV hyperimmune globulin may reduce vertical transmission and sequelae in neonates. A systematic review on valaciclovir and CMV hyperimmune globulin in preventing vertical transmission or reducing sequelae in neonates was conducted to 3 September 2021. Valaciclovir as a preventative strategy was supported by a well-conducted randomised controlled trial. Evidence supporting valaciclovir as a treatment strategy was limited to observational studies at moderate risk of bias. CMV hyperimmune globulin was not supported as a preventative strategy in two RCTs, which contrasted with observational studies. Evidence favouring CMV hyperimmune globulin as a treatment strategy was limited to observational studies at moderate risk of bias. The role of valaciclovir and CMV hyperimmune globulin in CMV infection in pregnancy is still being defined. Valaciclovir to prevent vertical transmission has the highest quality evidence in favour of use.

Late termination of pregnancy in case of congenital CMV infection: ethics, medicine and law

This paper provides a recent legal case which calls into discussion the women's safe access to voluntary termination of pregnancy (VTP) after the first 90 days. On 15 January 2021, the Italian Supreme Court sentenced a physician to damage compensation because he did not correctly inform the patient, in her 22nd week of pregnancy, about the risks to the fetus relating to an infection from cytomegalovirus (CMV). The option for VTP was not offered since, at the time of the woman's request, medical investigations did not show the evidence of fetal malformations, neither there were concrete risks for the life of the mother, as Italian law requires. The baby was born with severe brain injuries. The case is noteworthy because it offers a new precedent to extend legal requirements for late VTP. The impact of this decision must be tested in the clinical practice. Further studies are necessary to evaluate possible law amendments extending access conditions for this practice and new policies promoting the strengthening of informative and assistance procedures, including psychological help, to the pregnant woman are needed, as well.

The Current Challenges in Developing Biological and Clinical Predictors of Congenital Cytomegalovirus Infection

Congenital cytomegalovirus (CMV) infection may cause severe long-term sequelae. Recent studies have demonstrated that early antiviral therapy for infants with symptomatic congenital CMV (cCMV) infection may improve neurological outcomes; thus, accurate identification of newborns at high risk of cCMV infection may contribute to improved outcomes in affected children. However, maternal serological screening for cCMV infection by diagnosing primary infection during pregnancy, which is a popular screening strategy, is inefficient, because the number of cCMV infections with nonprimary causes, including reactivation of or reinfection with CMV, is larger than that of cCMV infections with primary causes. Low levels of neutralizing antibodies against pentameric complex and potent CMV-specific T cell-mediated immune responses are associated with an increased risk of cCMV infection. Conversely, our prospective cohort studies revealed that the presence of maternal fever/flu-like symptoms, threatened miscarriage/premature delivery, or actual premature delivery are risk factors for cCMV infection among both women with normal pregnancies and those with high-risk ones, regardless of whether the infection is primary or nonprimary. This review focused on host immune responses to human CMV and current knowledge of potential biological and clinical factors that are predictive of cCMV infection.

Current practices of management of maternal and congenital Cytomegalovirus infection during pregnancy after a maternal primary infection occurring in first trimester of pregnancy: Systematic review

INTRODUCTION

Congenital CMV infection is the first worldwide cause of congenital viral infection but systematic screening of pregnant women and newborns for CMV is still debated in many countries.

OBJECTIVES

This systematic review aims to provide the state of the art on current practices concerning management of maternal and congenital CMV infection during pregnancy, after maternal primary infection (PI) in first trimester of pregnancy.

DATA SOURCES

Electronically searches on databases and hand searches in grey literature.

STUDY ELIGIBILITY CRITERIA AND PARTICIPANTS

Primary outcome was listing biological, imaging, and therapeutic management interventions in two distinct populations: population 1 are pregnant women with PI, before or without amniocentesis; population 2 are pregnant women with congenitally infected fetuses (after positive amniocentesis). Secondary outcome was pregnancy outcome in population 2.

RESULTS

Out of 4,134 studies identified, a total of 31 studies were analyzed, with 3,325 pregnant women in population 1 and 1,021 pregnant women in population 2, from 7 countries (Belgium, France, Germany, Israel, Italy, Spain and USA). In population 1, ultrasound (US) examination frequency was 0.75/month, amniocentesis in 82% cases, maternal viremia in 14% and preventive treatment with hyperimmune globulins (HIG) or valaciclovir in respectively 14% and 4% women. In population 2, US examination frequency was 1.5/month, magnetic resonance imaging (MRI) in 44% cases at 32 weeks gestation (WG), fetal blood sampling (FBS) in 24% at 28 WG, and curative treatment with HIG or valaciclovir in respectively 9% and 8% patients.

CONCLUSIONS

This systematic review illustrates management of maternal and congenital CMV during pregnancy in published and non-published literature, in absence of international consensus.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42019124342.

Cytomegalovirus-A Risk Factor for Childhood Hearing Loss: A Systematic Review

OBJECTIVE

Permanent hearing loss is an important public health issue in children with consequences for language, social, and academic functioning. Early hearing detection, intervention, and monitoring are important in mitigating the impact of permanent childhood hearing loss. Congenital cytomegalovirus (CMV) infection is a leading cause of hearing loss. The purpose of this review was to synthesize the evidence on the association between CMV infection and permanent childhood hearing loss.

DESIGN

We performed a systematic review and examined scientific literature from the following databases: MEDLINE, Ovid MEDLINE(R) Daily and Ovid MEDLINE(R), Embase, and CINAHL. The primary outcome was permanent bilateral or unilateral hearing loss with congenital onset or onset during childhood (birth to 18 years). The secondary outcome was progressive hearing loss. We included studies reporting data on CMV infection. Randomized controlled trials, quasi-experimental studies, nonrandomized comparative and noncomparative studies, and case series were considered. Data were extracted and the quality of individual studies was assessed with the Qualitative Assessment Tool for Quantitative Studies (McMaster University). The quality and strength of the evidence were graded using the Grading of Recommendations Assessment, Development and Evaluation (GRADE). A narrative synthesis was completed.

RESULTS

Sixty-five articles were included in the review. Prevalence of hearing loss at birth was over 33% among symptomatic CMV-infected newborns and less than 15% in asymptomatic infections. This difference in prevalence was maintained during childhood with more than 40% prevalence reported for symptomatic and less than 30% for asymptomatic CMV. Late-onset and progressive hearing loss appear to be characteristic of congenital CMV infections. Definitions of hearing loss, degree of loss, and reporting of laterality varied across studies. All degrees and both bilateral and unilateral loss were reported, regardless of symptomatic and asymptomatic status at birth, and no conclusions about the characteristics of hearing loss could be drawn. Various patterns of hearing loss were reported including stable, progressive, and fluctuating, and improvement in hearing (sometimes to normal hearing) was documented. These changes were reported in children with symptomatic/asymptomatic congenital CMV infection, presenting with congenital/early onset/late-onset hearing loss and in children treated and untreated with antiviral medication.

CONCLUSIONS

Symptomatic and asymptomatic congenital CMV infection should be considered a risk factor for hearing loss at birth and during childhood and for progressive hearing loss. Therefore, CMV should be included as a risk factor in screening and surveillance programs and be taken into account in clinical follow-up of children with hearing loss.

Secondary prevention of congenital cytomegalovirus infection with valacyclovir following maternal primary infection in early pregnancy

OBJECTIVE

Cytomegalovirus (CMV) maternal primary infection (MPI) in early pregnancy is the main risk factor for congenital CMV (cCMV) infection with long-term sequelae. Our aim was to evaluate, in a single center offering CMV serology screening at 11-14 gestational weeks, secondary prevention of cCMV by administration of high-dosage maternal oral valacyclovir (VACV) in the first trimester of pregnancy.

METHODS

This was a case-control study in a longitudinal cohort of pregnancies with CMV-MPI diagnosed prior to 14 weeks of gestation by serology screening (immunoglobulin (Ig) M and IgG measurement and IgG avidity) between 2009 and 2020. From October 2019 onwards, all women presenting at our center with MPI before 14 weeks' gestation were offered treatment with high-dosage oral VACV (8 g/day, 4 g twice/day). We used propensity score matching to compare fetal infection rates in cases treated with maternal oral VACV (8 g/day) with those in untreated controls. Fetal infection was assessed following amniocentesis at 17-22 weeks of gestation, by polymerase chain reaction (PCR) analysis of amniotic fluid for viral DNA.

RESULTS

Of 310 cases of CMV-MPI identified, 269 underwent amniocentesis for PCR. Of these, 66 were offered, and 65 accepted, treatment with VACV. From the remaining untreated cases, we selected 65 controls, matched for proportion of periconceptional infections and gestational age at amniocentesis. VACV was initiated at a median gestational age of 12.71 (interquartile range (IQR), 10.00-13.86) weeks and the median duration of treatment was 35 (IQR, 26-54) days. On multivariate logistic regression, fetal infection was lower in the treated group (odds ratio, 0.318 (95% CI, 0.120-0.841); P = 0.021). One treated patient developed acute renal failure 4 weeks after initiation of VACV therapy, but this resolved within 5 days after treatment was stopped.

CONCLUSION

This study confirms the acceptability, tolerance and benefit of secondary prevention by VACV of cCMV infection in a clinical setting with a well-established routine maternal serum screening policy in the first trimester of pregnancy. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.

Congenital Cytomegalovirus Infection: Epidemiology, Timely Diagnosis, and Management

Congenital cytomegalovirus (cCMV) infection is common because of the ubiquitous nature of the virus and the lack of an effective prevention strategy during pregnancy. Most infants with cCMV are asymptomatic, although a notable subset can have sequelae including, most commonly, sensorineural hearing loss and neurodevelopmental disability, which may not be present at birth. Timely screening for cytomegalovirus in the first weeks after birth is critical to appropriately diagnose congenital infection, evaluate affected infants, and determine the treatment course. Antiviral therapy with valganciclovir can optimize end hearing and neurodevelopmental outcomes in symptomatic infants. This review discusses the epidemiology and clinical manifestations of cCMV, targeted and universal screening approaches, and treatment and monitoring of infants with cCMV.

New evidence on prognostic features, prevention and treatment of congenital Cytomegalovirus infection

PURPOSE OF REVIEW

Congenital Cytomegalovirus (CMV) infection remains a major cause of lifelong disability, with no systematic screening implemented in pregnancy or the postnatal period. In this review article, we outline the preventive strategies, antenatal prognostic features and experimental therapies as well as evidence of efficacy from recent trials.

RECENT FINDINGS

A recent randomized, double blinded, placebo-controlled study investigated the efficacy of Valaciclovir in women contracting primary CMV in the periconception period or first trimester. They concluded that Valaciclovir at a dose of 8 g/day is effective in reducing the rate of foetal CMV infection following early maternal primary infection. Administration of CMV hyperimmune globulin (HIG) was investigated in a recent randomized double-masked controlled trial. This study concluded that CMV HIG was ineffective at reducing the risk of congenital CMV among women with primary CMV in early pregnancy.

SUMMARY

Congenital CMV infection remains a significant cause of disability. There is currently no vaccine available, with the best preventive strategy being patient education on transmission as well as hygiene measures to reduce risk of exposure. Experimental therapies have been investigated in recent years and there is evidence supporting the use of Valaciclovir. Data for the efficacy of CMV HIG remains inconsistent and administration is currently limited to clinical trial settings.

Prevention strategies for congenital cytomegalovirus infection

PURPOSE OF REVIEW

Cytomegalovirus (CMV) is the most common viral cause of congenital infection, occurring in approximately 1-2% of live births worldwide. Given our increasing knowledge of risk, advances in the identification of maternal infection, and the extremely limited options for the treatment of fetal infection, the prevention is a promising direction for research efforts. Recently, there have been several exciting studies assessing different ways of preventing congenital infection in the fetus and one in particular has focused on the use of valaciclovir.

RECENT FINDINGS

A recent study reported a 71% reduction in vertical transmission of CMV with the use of oral valaciclovir following maternal primary CMV infection early in pregnancy. The clinical impact of this study could be enormous and it has particular implications for considerations around maternal serological screening in the first trimester of pregnancy. Further research assessing behaviour modifications during early pregnancy could also provide evidence for an effective primary prevention technique.

SUMMARY

Prevention of congenital CMV infection, whether primary, secondary or tertiary, is possible, however, there are barriers to its utilisation in a clinical setting. The main limitation is the requirement for early, effective and large-scale serological screening of mothers to detect asymptomatic primary infection.

Vertical Transmission and Discordance of Cytomegalovirus in Twin Pregnancies

Objective

The objectives are to estimate the vertical transmission rate in twins relative to singleton pregnancies, to evaluate whether discordance within twin pairs is rare, and to characterize concordance within monozygotic and dizygotic twin pairs in relation to hereditability.

Methods

We first sought to estimate the vertical transmission rate of congenital CMV infection in twins by gathering cohort-based studies of congenital CMV in which vertical transmission in both singleton and twin pregnancies was reported. This also allowed us to compare singleton and twin infection rates. From the above studies and other large cohorts of congenitally infected infants, the percentage of discordantly infected twin pairs determined whether this is a rare phenomenon. Theorizing discordance is not rare, we then analyzed data from cases with twin outcomes for congenital CMV infection, according to whether the twins were monozygotic or dizygotic, and calculated their corresponding concordance rates to estimate the broad-sense heritability. Lastly, we described other factors that might affect vertical transmission.

Results

From five articles following at-risk pregnancies, the rate of vertical transmission in twin pregnancies is 58.7% (95% CI 43.3-72.3%) whereas in singleton pregnancies it is 31.4% (95% CI: 29.0-34.0%) p = 0.0002. Of ten studies of larger cohorts of infants with congenital CMV infection, 21 of 42 twin pairs with at least one twin infected were discordant for congenital CMV (50.0%, 95% CI: 34.4–65.6%) indicating discordance of congenital CMV infection in twin pairs is not rare. Of 28 studies covering 37 twin pairs where at least one twin had congenital CMV, and zygosity was known, eleven of thirteen monozygotic twin pairs (84.6%; 95% CI: 53.7-97.3%) were concordant for CMV infection, and nine of twenty-four dizygotic twin pairs (37.5%; 95% CI: 19.6-59.2%) were concordant for infection giving an estimated hereditability of 94.2%. Within these 37 twin pairs, factors such as primary or recurrent maternal infection, prematurity, growth discordance, and sex are described; however, in many of these cases these factors are unknown.

Conclusion

The rate of vertical transmission of congenital CMV is higher for twins than singletons. Discordance of congenital CMV in twins is not rare and suggests a possible genetic susceptibility to congenital CMV.

Congenital cytomegalovirus infection in twin pregnancy

Cytomegalovirus (CMV) infection is one of the preeminent congenital viral infections, and despite its potential morbidity, uncertainty about its physiopathology, prevention and treatment remains until now. We report a case of a dichorionic and diamniotic twin pregnancy in which only one of the fetus had signs of being affected. The first twin had prenatal diagnosis of intrauterine growth restriction and hyperechogenic bowel, attributable to CMV infection, while there was no evidence of infection of the second one. Prenatal treatment was done with maternal administration of valacyclovir and postnatal treatment of the infected newborn with oral valganciclovir with normal neurodevelopment assessment at 12 months corrected age. In this case, maternal CMV infection was not equally transmitted to both fetuses, suggesting that there may be intrinsic fetal and placental factors influencing both transmission and the clinical features of the infection.

Guideline No. 420: Cytomegalovirus Infection in Pregnancy

OBJECTIVE

To provide an update on current recommendations for cytomegalovirus (CMV) infection during pregnancy. The objectives of this guideline are: TARGET POPULATION: Patients of child-bearing age, pregnant patients, and patients planning a pregnancy.

BENEFITS, HARMS, AND COSTS

The patient partners urged us to make awareness of preventive strategies a high priority, despite concern that discussing CMV with patients could cause unnecessary anxiety. CMV educational interventions have shown benefits from increased awareness of cCMV prevalence and preventive strategies among providers, patients, and families.

EVIDENCE

We searched MEDLINE, EMBASE, and CENTRAL databases for CMV in pregnancy. The search terms were developed using MeSH terms and keywords (Appendix). The results were filtered for articles published between January 2010 and October 2020 and systematic reviews, meta-analyses, clinical trials, and observational studies. The main inclusion criteria were pregnant patients and infants, as the target population, and CMV infection, as the diagnosis of interest. Recommendations are graded according to the U.S. Preventive Services Task Force grade of recommendations and level of certainty.

VALIDATION METHODS

We collaborated with patient partners, including members of CMV Canada (cmvcanada.com). In formulating our recommendations, we included patients' voices to add a unique and valuable perspective, thus ensuring that our recommendations are relevant to the patient-provider partnership.

INTENDED AUDIENCE

All perinatal health care providers. RECOMMENDATIONS (GRADE AND LEVEL OF CERTAINTY IN PARENTHESES).