Reconsideration of Maternal Serological Testing for Predicting Congenital CMV Infection

BACKGROUND

The value of the widely applied maternal cytomegalovirus (CMV) serological testing approach in predicting intrauterine transmission in highly seroprevalent regions remains unknown.

METHODS

A nested case-control study was conducted based on a maternal-child cohort study. Newborns with congenital CMV (cCMV) infection were included, and each of them was matched to 3 newborns without cCMV infection. Retrospective samples were tested for immunoglobulin G (IgG) avidity and immunoglobulin M (IgM) antibodies in maternal serum and CMV DNA in maternal blood and urine to analyze their associations with cCMV infection.

RESULTS

Forty-eight newborns with cCMV infection and 144 matched newborns without infection were included in the study. Maternal IgM antibodies and IgG avidity during pregnancy were not statistically associated with intrauterine transmission. The presence of CMV DNAemia indicated a higher risk of cCMV infection, with odds ratio values of 5.7, 6.5, and 13.0 in early, middle, and late pregnancy, respectively. However, the difference in CMV shedding rates in transmitters and nontransmitters was not significant in urine.

CONCLUSIONS

The value of current maternal CMV serological testing in regions with high seropositivity rates is very limited and should be reconsidered. The detection of DNAemia would be helpful in assessing the risk of intrauterine transmission.

Long-term follow-up of a series of 24 congenital CMV-infected babies with false negative amniocentesis

BACKGROUND

Congenital CMV infection is the most common congenital infection worldwide and a major cause of neurological impairment and sensorineural hearing loss. Fetal CMV infection is confirmed by a positive PCR test in the amniotic fluid (amniocentesis performed after 18-20 weeks of gestation and at least 8 weeks after maternal infection). However, despite a negative antenatal CMV PCR result, some newborns can be tested positive at birth. Although not widely documented, the prognosis for these babies appears to be good.

OBJECTIVES

The aim of this study is to evaluate the long-term prognosis of fetuses with a false-negative AFS for cCMV, with a minimum follow-up period of 6 years.

STUDY DESIGN

This is a retrospective cohort study of false-negative amniocentesis reported at the CUB-Hôpital Erasme and Hôpital CHIREC in Brussels between 1985 and 2017.

RESULTS

Of the 712 negative CMV PCR amniocenteses, 24 had a CMV PCR positive at birth. The false negative rate was 8.6 %. Of the 24 cases, 9 primary maternal infections occurred in the first trimester, 14 in the second trimester and 1 in the third trimester. Among the 24 children, 2 had symptoms at birth (hyperbilirubinemia and left paraventricular cysts), but all had normal follow-up (minimum 4 years, mean 16,6 years).

DISCUSSION

Only 2 cases could be explained by early amniocentesis. Among the others, the false-negative results could be attributed to a low viral load, a delayed infection or, less likely, to a sample degradation.

CONCLUSION

Despite the false-negative results, all 24 children had a normal long-term follow-up.

Antiviral Treatment of Maternal and Congenital Cytomegalovirus (CMV) Infections

Human Cytomegalovirus (HCMV) is a ubiquitous member of the Herpesviridae family, responsible for the most common congenital viral infection-congenital Cytomegalovirus (cCMV) infection. While a majority of HCMV infections in children and adults are asymptomatic, HCMV is well known to cause severe infections in the immunocompromised individual and maternal infections with variable long-term sequelae after maternal-fetal transmission with primary or nonprimary infections. HCMV seroprevalence and cCMV incidence vary by geographic area and demographic characteristics like race and socioeconomic status. While cCMV birth prevalence ranges from 0.2% to 6% in different parts of the world, it is influenced by regional HCMV seroprevalence rates. HCMV screening during pregnancy is not routinely offered due to lack of awareness, hurdles to accurate diagnosis, and lack of well-established effective treatment options during pregnancy. This review will focus on antiviral treatment options currently available for use during pregnancy and in the newborn period for the treatment of maternal and congenital HCMV infections.

Treatment with valacyclovir during pregnancy for prevention of congenital cytomegalovirus infection: a real-life multicenter Italian observational study

BACKGROUND

Valacyclovir is the only treatment demonstrated to be effective for the prevention of vertical transmission of cytomegalovirus within a clinical randomized, placebo-controlled trial and has been reimbursed by the Italian National Health System since December 2020.

OBJECTIVE

This study reported the results of a real-life Italian multicenter observational study on cytomegalovirus infection in pregnancy evaluating the effect of the introduction of valacyclovir in the clinical practice for the prevention of vertical transmission of cytomegalovirus.

STUDY DESIGN

The outcomes of women who received valacyclovir treatment and their fetuses or newborns were compared with those of a retrospective cohort observed between 2010 and 2020 who did not receive the antiviral treatment. The inclusion criterion was the diagnosis of cytomegalovirus primary infection occurring in the periconceptional period or up to 24 weeks of gestation. The primary outcome was the transmission by the time of amniocentesis. The secondary outcomes were termination of pregnancy, transmission at birth, symptomatic infection at birth, and a composite outcome (termination of pregnancy or transmission at birth).

RESULTS

A total of 447 pregnant women from 10 centers were enrolled, 205 women treated with valacyclovir (called the valacyclovir group, including 1 twin pregnancy) and 242 women not treated with valacyclovir (called the no-valacyclovir group, including 2 twin pregnancies). Valacyclovir treatment was significantly associated with a reduction of the diagnosis of congenital cytomegalovirus infection by the time of amniocentesis (weighted odds ratio, 0.39; 90% confidence interval, 0.22-0.68; P=.005; relative reduction of 61%), termination of pregnancy (weighted odds ratio, 0.36; 90% confidence interval, 0.17-0.75; P=.0021; relative reduction of 64%), symptomatic congenital cytomegalovirus infection at birth (weighted odds ratio, 0.17; 90% confidence interval, 0.06-0.49; P=.006; relative reduction of 83%). The treatment had no significant effect on the rate of diagnosis of congenital cytomegalovirus infection at birth (weighted odds ratio, 0.85; 90% confidence interval, 0.57-1.26; P=.500), but the composite outcome (termination of pregnancy or diagnosis of congenital cytomegalovirus infection at birth) occurred more frequently in the no-valacyclovir group (weighted odds ratio, 0.62; 90% confidence interval, 0.44-0.88; P=.024). Of note, the only symptomatic newborns with congenital cytomegalovirus infection in the valacyclovir group (n=3) were among those with positive amniocentesis. Moreover, 19 women (9.3%) reported an adverse reaction to valacyclovir treatment, classified as mild in 17 cases and moderate in 2 cases. Lastly, 4 women (1.9%) presented renal toxicity with a slight increase in creatinine level, which was reversible after treatment suspension.

CONCLUSION

Our real-life data confirm that valacyclovir significantly reduces the rate of congenital cytomegalovirus diagnosis at the time of amniocentesis with a good tolerability profile and show that the treatment is associated with a reduction of termination of pregnancy and symptomatic congenital cytomegalovirus infection at birth.

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.

New data on efficacy of valacyclovir in secondary prevention of maternal-fetal transmission of cytomegalovirus

OBJECTIVE

Congenital cytomegalovirus (CMV) infection is the leading cause of non-genetic hearing and neurological deficits. The aim of our study was to evaluate the efficacy and safety of valacyclovir (VCV) treatment in preventing CMV transmission to the fetus after maternal primary infection.

METHODS

This was a retrospective, multicenter study evaluating the rate of maternal-fetal CMV transmission in pregnancies with maternal primary CMV infection treated with VCV at a dosage of 8 g per day (VCV group) compared with a control group of untreated women. Each case underwent virological testing to confirm maternal primary infection and to provide accurate dating of onset of infection. The primary outcome was the presence of congenital CMV infection at birth diagnosed based on polymerase chain reaction analysis of saliva, urine and/or blood samples. The efficacy of VCV treatment was assessed using logistic regression analysis adjusted for a propensity score.

RESULTS

In total, 143 patients were included in the final analysis, of whom 59 were in the VCV group and 84 were in the untreated control group. On propensity-score-adjusted analysis, VCV treatment was significantly associated with an overall reduction in the rate of maternal-fetal CMV transmission (odds ratio, 0.40 (95% CI, 0.18-0.90); P = 0.029). The rate of maternal-fetal CMV transmission, determined at birth, in the VCV vs control group was 7% (1/14) vs 10% (1/10) after periconceptional maternal primary infection (P = 1.00), 22% (8/36) vs 41% (19/46) after first-trimester maternal primary infection (P = 0.068) and 25% (2/8) vs 52% (14/27) after second-trimester maternal primary infection (P = 0.244). When analyzing the efficacy of VCV treatment according to maternal viremia at treatment initiation, there was a trend towards greater efficacy when patients were viremia-positive (21% vs 43%; P = 0.072) compared with when they were viremia-negative (22% vs 17%; P = 0.659). Maternal side effects associated with VCV were mild and non-specific in most cases.

CONCLUSION

Our findings indicate that VCV treatment of pregnant women with primary CMV infection reduces the risk of maternal-fetal transmission of CMV and may be effective in cases with primary infection in the first and second trimesters. © 2022 International Society of Ultrasound in Obstetrics and Gynecology.

Amniocentesis to diagnose congenital cytomegalovirus infection following maternal primary infection

BACKGROUND

Congenital cytomegalovirus infection following maternal primary cytomegalovirus infection affects approximately 0.4% of newborns in the United States but may be hard to diagnose prenatally.

OBJECTIVE

To evaluate the current sensitivity and specificity of amniocentesis in detecting congenital cytomegalovirus infection.

STUDY DESIGN

Secondary analysis of a multicenter randomized placebo-controlled trial designed to evaluate whether cytomegalovirus hyperimmune globulin reduces congenital cytomegalovirus infection in neonates of individuals diagnosed with primary cytomegalovirus infection before 24 weeks of gestation. At randomization, subjects had no clinical evidence of fetal infection. Eligible subjects were randomized to monthly infusions of cytomegalovirus hyperimmune globulin or placebo until delivery. Although not required by the trial protocol, amniocentesis following randomization was permitted. The fetuses and neonates were tested for the presence of cytomegalovirus at delivery. Comparisons were made between those with and without amniocentesis and between those with cytomegalovirus-positive and negative results, using chi-square or Fisher exact test for categorical variables and the Wilcoxon rank sum test or t test for continuous variables. A P value of <.05 was considered significant.

RESULTS

From 2012 to 2018, 397 subjects were included, of whom 55 (14%) underwent amniocentesis. Cytomegalovirus results were available for 53 fetuses and neonates. Fourteen amniocenteses were positive (25%). Gestational age at amniocentesis was similar between those with and without cytomegalovirus present, as was the interval between maternal diagnosis and amniocentesis. The prevalence of fetal or neonatal infection was 26% (14/53). The neonates of all 12 subjects with a positive amniocentesis and available results had cytomegalovirus infection confirmed at delivery, as did 2 neonates from the group of 41 subjects with a negative amniocentesis, with a sensitivity of 86% (95% confidence interval, 57-98), specificity of 100% (95% confidence interval, 91-100), positive predictive value of 100% (95% confidence interval, 74-100), and negative predictive value of 95% (95% confidence interval, 83-99). Amniocentesis-positive pregnancies were delivered at an earlier gestational age (37.4 vs 39.6 weeks; P<.001) and had lower birthweights (2583±749 vs 3428±608 g, P=.004) than amniocentesis-negative pregnancies.

CONCLUSION

Amniocentesis results are an accurate predictor of congenital cytomegalovirus infection.

Assessment of HCMV-encoded microRNAs in plasma as potential biomarkers in pregnant women with adverse pregnancy outcomes

Background

Human cytomegalovirus (HCMV) is the most frequent cause of congenital infections and can lead to adverse pregnancy outcomes (APOs). HCMV encodes multiple microRNAs (miRNAs) that have been reported to be partially related to host immune responses, cell cycle regulation, viral replication, and viral latency, and can be detected in human plasma. However, the relevance for HCMV-encoded miRNAs in maternal plasma as an indicator for APOs has never been evaluated.

Methods

Expression profiles of 22 HCMV-encoded miRNAs were first measured in plasma samples from 20 pregnant women with APOs and 28 normal controls using quantitative reverse-transcription polymerase chain reaction. Next, markedly changed miRNAs were validated in another independent validation set consisting of 20 pregnant women with APOs and 27 control subjects. Markedly changed miRNAs were further assessed in the placenta tissues. HCMV DNA in peripheral blood leukocytes (PBLs) and anti-HCMV immunoglobulin M (IgM) and anti-HCMV immunoglobulin G (IgG) in plasma were also examined in both training and validation sets. Diagnostic value and risk factors were compared between APO cohorts and normal controls.

Results

Analysis of the training and validation data sets revealed that plasma concentrations of hcmv-miR-UL148D, hcmv-miR-US25-1-5p and hcmv-miR-US5-1 were significantly increased in pregnant women with APOs compared with normal controls. Hcmv-miR-US25-1-5p presented the largest area under the receiver-operating characteristic (ROC) curve (AUC) (0.735; 95% CI, 0.635–0.836), with a sensitivity of 68% and specificity of 71%. Furthermore, plasma levels of hcmv-miR-US25-1-5p and hcmv-miR-US5-1 correlated positively with APOs (P=0.029 and 0.035, respectively). Hcmv-miR-US25-1-5p in the placenta tissues were dramatically increased in APOs, and correlated with plasma hcmv-miR-US25-1-5p. Nevertheless, neither the concentration of HCMV DNA in PBLs nor the positivity rates of anti-HCMV IgM and anti-HCMV IgG in plasma showed a statistically significant correlation with APOs.

Conclusions

We identified a unique signature of HCMV-encoded miRNAs in pregnant women with APOs that may be useful as a potential noninvasive biomarker for predicting and monitoring APOs during HCMV infection.

Maternal infections: revisiting the need for screening in pregnancy

The decision to implement screening for infections during pregnancy depends upon epidemiological, economic, therapeutic and test performance criteria. It therefore varies with public health priorities from country to country. When screening is implemented, the first trimester has become the best time slot to build individual care pathways in this field. This is most relevant for evaluating the risk of embryonic consequences, planning diagnostic testing, initiating primary or secondary prevention and optimising the accuracy of ultrasound follow-up. This article is a critical appraisal of epidemiological data and current international screening recommendations for infections in pregnancy. TWEETABLE ABSTRACT: Screening for infections in pregnancy: a critical review of current epidemiological evidence and international guidelines.

Cytomegalovirus infection in pregnancy - An update

Cytomegalovirus (CMV) is a ubiquitous DNA virus with a global seroprevalence of 83 %. It is the most common pathogen causing teratogenic congenital infection. It is therefore a major public health concern. Maternal infection is associated with congenital CMV (cCMV), the leading cause of non-genetic sensorineural hearing loss. cCMV also causes impairment of cognitive development and cerebral palsy. Transmission of CMV occurs through direct contact with bodily fluids such as saliva, urine or semen from someone who is actively shedding the virus. Transmission rates are higher after primary infection with the rate of transmission increasing with gestational age. Severe fetal effects are however more common when infection occurs before 20weeks. Past infection does not confer immunity to mother or protect the fetus. cCMV may present with cerebral or extracerebral abnormalities on ultrasound, fetal growth restriction and fetal loss. Diagnosis of primary maternal CMV in pregnancy should be based on seroconversion in pregnancy (de novo appearance of virus-specific immunoglobulin G (IgG) in the serum of pregnant women who were previously seronegative) or on detection of specific immunoglobulin M (IgM) and IgG antibodies in association with low IgG avidity. Prenatal diagnosis of fetal CMV is imperfect and based on amniocentesis performed at least 8 weeks after presumed maternal infection and after 17 weeks of gestation. Hygiene information and education of pregnant women is currently the most effective strategy for prevention of CMV infection. The role of vaccines, antiviral drugs and immunoglobulins remains unproven.

Sequelae of Congenital Cytomegalovirus Following Maternal Primary Infections Are Limited to Those Acquired in the First Trimester of Pregnancy

BACKGROUND

The known relationship between the gestational age at maternal primary infection an the outcome of congenital CMV is based on small, retrospective studies conducted between 1980 and 2011. They reported that 32% and 15% of cases had sequelae following a maternal primary infection in the first and second or the third trimester, respectively. We aimed to revisit this relationship prospectively between 2011 and 2017, using accurate virological tools.

METHODS

We collected data on women with a primary infection and an infected child aged at least 1 year at the time of analysis. An accurate determination of the timing of the primary infection was based upon serial measurements of immunoglobulin (Ig) M and IgG and on IgG avidity in sera collected at each trimester. The case outcome was assessed according to a structured follow-up between birth and 48 months.

RESULTS

We included 255 women and their 260 fetuses/neonates. The dating of the maternal infection was prospective in 86% of cases and retrospective in 14%. At a median follow-up of 24 months, the proportion of sensorineural hearing loss and/or neurologic sequelae were 32.4% (95% confidence interval [CI] 23.72-42.09) after a maternal primary infection in the first trimester, 0 (95% CI 0-6.49) after an infection in the second trimester, and 0 (95% CI 0-11.95) after an infection in the third trimester (P < .0001).

CONCLUSIONS

These results suggest that a cytomegalovirus infection can be severe only when the virus hits the fetus in the embryonic or early fetal period. Recent guidelines recommend auditory follow-ups for at least 5 years for all infected children. This raises parental anxiety and generates significant costs. We suggest that auditory and specialized neurologic follow-ups may be recommended only in cases of a maternal infection in the first trimester.

Valaciclovir to prevent vertical transmission of cytomegalovirus after maternal primary infection during pregnancy: a randomised, double-blind, placebo-controlled trial

BACKGROUND

Cytomegalovirus is a common congenital infection, with high morbidity after an early primary maternal infection. No effective means exist to prevent viral transmission to the fetus. We aimed to investigate whether valaciclovir can prevent vertical transmission of cytomegalovirus to the fetus in pregnant women with a primary infection acquired early in pregnancy.

METHODS

This prospective, randomised, double-blind, placebo-controlled trial was done at the Infectious Feto-Maternal Clinic of Rabin Medical Center (Petach Tikvah, Israel). Pregnant women aged 18 years or older, with serological evidence of a primary cytomegalovirus infection acquired either periconceptionally or during the first trimester of pregnancy, were randomly assigned to oral valaciclovir (8 g per day, twice daily) or placebo from enrolment until amniocentesis at 21 or 22 gestational weeks. Randomisation was done separately for participants infected periconceptionally or during the first trimester and was done in blocks of four. Patients and researchers were masked to participant allocation throughout the entire study period. The primary endpoint was the rate of vertical transmission of cytomegalovirus. Statistical analyses were done according to per-protocol principles. The study was registered at ClinicalTrials.gov, NCT02351102.

FINDINGS

Between Nov 15, 2015, and Oct 8, 2018, we enrolled and randomly assigned 100 patients to receive valaciclovir or placebo. Ten patients were excluded, five from each study group; therefore, the final analysis included 45 patients (all singletons) in the valaciclovir group and 45 patients (43 singletons and two sets of twins) in the placebo group. In the valaciclovir group, including both first trimester and periconceptional infections, five (11%) of 45 amniocenteses were positive for cytomegalovirus, compared with 14 (30%) of 47 amniocenteses in the placebo group (p=0·027; odds ratio 0·29, 95% CI 0·09-0·90 for vertical cytomegalovirus transmission). Among participants with a primary cytomegalovirus infection during the first trimester, a positive amniocentesis for cytomegalovirus was significantly less likely in the valaciclovir group (two [11%] of 19 amniocenteses) compared with the placebo group (11 [48%] of 23 amniocenteses; p=0·020. No clinically significant adverse events were reported.

INTERPRETATION

Valaciclovir is effective in reducing the rate of fetal cytomegalovirus infection after maternal primary infection acquired early in pregnancy. Early treatment of pregnant women with primary infection might prevent termination of pregnancies or delivery of infants with congenital cytomegalovirus.

FUNDING

None.

Cytomegalovirus infection during pregnancy: state of the science

Cytomegalovirus is the most common congenital infection, affecting 0.5-2% of all live births and the main nongenetic cause of congenital sensorineural hearing loss and neurological damage. Congenital cytomegalovirus can follow maternal primary infection or nonprimary infection. Sensorineurological morbidity is confined to the first trimester with up to 40-50% of infected neonates developing sequelae after first-trimester primary infection. Serological testing before 14 weeks is critical to identify primary infection within 3 months around conception but is not informative in women already immune before pregnancy. In Europe and the United States, primary infection in the first trimester are mainly seen in young parous women with a previous child younger than 3 years. Congenital cytomegalovirus should be evoked on prenatal ultrasound when the fetus is small for gestation and shows echogenic bowel, effusions, or any cerebral anomaly. Although the sensitivity of routine ultrasound in predicting neonatal symptoms is around 25%, serial targeted ultrasound and magnetic resonance imaging of known infected fetuses show greater than 95% sensitivity for brain anomalies. Fetal diagnosis is done by amniocentesis from 17 weeks. Prevention consists of both parents avoiding contact with body fluids from infected individuals, especially toddlers, from before conception until 14 weeks. Candidate vaccines failed to provide more than 75% protection for >2 years in preventing cytomegalovirus infection. Medical therapies such as cytomegalovirus hyperimmune globulins aim to reduce the risk of vertical transmission but 2 randomized controlled trials have not found any benefit. Valaciclovir given from the diagnosis of primary infection up to amniocentesis decreased vertical transmission rates from 29.8% to 11.1% in the treatment group in a randomized controlled trial of 90 pregnant women. In a phase II open-label trial, oral valaciclovir (8 g/d) given to pregnant women with a mildly symptomatic fetus was associated with a higher chance of delivering an asymptomatic neonate (82%), compared with an untreated historical cohort (43%). Valganciclovir given to symptomatic neonates is likely to improve hearing and neurological symptoms, the extent of which and the duration of treatment are still debated. In conclusion, congenital cytomegalovirus infection is a public health challenge. In view of recent knowledge on diagnosis and pre- and postnatal management, health care providers should reevaluate screening programs in early pregnancy and at birth.

Acute Perinatal Infection and the Evidenced-Based Risk of Intrauterine Diagnostic Testing: A Structured Review

BACKGROUND

The prevalence of perinatal infection from maternal exposure is increasing. The prevalence of acute maternal infections identifies cytomegalovirus, parvovirus B19, toxoplasmosis, and varicella as the most common organisms and in the order of frequency. Maternal informed consent and understanding is required before intrauterine testing for fetal infectious and possible genetic risk assessment.

METHODS

This structured review of the reproductive published literature focuses on the risks of amniocentesis and cordocentesis diagnostic procedure-related fetal loss rates and fetal vertical transmission (VT) rates from published infected pregnant cohorts.

RESULTS

The total postprocedure fetal loss rate for diagnostic amniocentesis procedures, in limited infectious cohorts, is 1.5% and does not appear to be increased compared to "noninfected" amniocentesis cohorts using an estimated background spontaneous fetal loss rate (no procedure) of 0.65%. The "pooled" unintended fetal loss rate is from small infected population cohorts, but can be used for counseling purposes. Postcordocentesis fetal loss risk, in an infected cohort, is not possible to estimate due to limited data. The "biological spontaneous fetal loss rate" risk with a perinatal infection (positive or negative fetal anomalies) and no diagnostic procedure before 20 weeks of gestation is reviewed. The risk of VT in acute infection cohorts as a result of the intra-amniotic diagnostic procedure is not found to be increased.

CONCLUSION

The unintended "fetal loss" rate after amniocentesis for perinatal infected cohorts is similar to that of noninfected cohorts, but the estimate is based on limited infected cohorts. There was no procedure-based risk of fetal VT in the infected cohorts, but identification of postprocedure maternal bleeding into the amniotic cavity increases the potential risk. Maternal knowledge translation and an informed consent process with risk-benefit maternal/fetal risk counseling are required prior to any diagnostic amniocentesis procedure.

Performance of Zika Assays in the Context of Toxoplasma gondii, Parvovirus B19, Rubella Virus, and Cytomegalovirus (TORCH) Diagnostic Assays

Infections during pregnancy that may cause congenital abnormalities have been recognized for decades, but their diagnosis is challenging. This was again illustrated with the emergence of Zika virus (ZIKV), highlighting the inherent difficulties in estimating the extent of pre- and postnatal ZIKV complications because of the difficulties in establishing definitive diagnoses. We reviewed the epidemiology, infection kinetics, and diagnostic methods used for Toxoplasma gondii, parvovirus B19, rubella virus, and cytomegalovirus (TORCH) infections and compared the results with current knowledge of ZIKV diagnostic assays to provide a basis for the inclusion of ZIKV in the TORCH complex evaluations. Similarities between TORCH pathogens and ZIKV support inclusion of ZIKV as an emerging TORCH infection. Our review evaluates the diagnostic performance of various TORCH diagnostic assays for maternal screening, fetal screening, and neonatal screening. We show that the sensitivity, specificity, and positive and negative predictive value of TORCH complex pathogens are widely variable, stressing the importance of confirmatory testing and the need for novel techniques for earlier and accurate diagnosis of maternal and congenital infections. In this context it is also important to acknowledge different needs and access to care for different geographic and resource settings.

Congenital cytomegalovirus infection: management update

PURPOSE OF REVIEW

Until recently, management options in congenital cytomegalovirus (cCMV) infection have been either conservative or termination of pregnancy. However, medical therapies aimed at reducing the risk of infection and/or its severity have recently been investigated.

RECENT FINDINGS

In a phase 2 open label, nonrandomized trial, valaciclovir (ValACV) was given to women carrying a CMV-infected fetus. ValACV was associated with a greater proportion of asymptomatic neonates when compared with a historical cohort (82 vs. 43%). However, the study design and the small number of treated women limit its applicability. Even though initial observational data suggested that hyperimmune globulin (HIG) therapy in pregnancy was associated with a significantly lower risk of cCMV, its efficacy has not been borne out in a subsequent phase 2 randomized, placebo controlled, double-blind study [cCMV 30% in the HIG group, 44% in the placebo group (P = 0.13)]. Furthermore, 11% of fetuses in the HIG group had transient or permanent abnormalities, compared with 16% in the placebo group.

SUMMARY

ValACV might have a promising role in the antenatal treatment of cCMV infection, but definitive recommendations require further research. The use of HIG should currently be limited to the research setting.Video abstract http://links.lww.com/COID/A18.

Cytomegalovirus

Cytomegalovirus (CMV), the largest of the herpesviruses, causes a wide range of clinical syndromes, from asymptomatic infection to severe disease in immunocompromised hosts. Laboratory methods for diagnosis include molecular testing, antigenemia, culture, serology, and histopathology. Treatment of CMV infection and disease is indicated in selected immunocompromised hosts, and preventive approaches are indicated in high-risk groups. This chapter reviews the epidemiology, clinical aspects, and the laboratory diagnosis and management of CMV in immunocompromised hosts.

Fetal cytomegalovirus infection

Cytomegalovirus (CMV) congenital infection affects 0.7% of live births worldwide and is the leading cause of congenital neurological handicap of infectious origin. However, systematic screening for this infection has not been implemented in pregnancy or at birth in any country. This apparent paradox had been justified by persisting gaps in the knowledge of this congenital infection: uncertain epidemiological data, difficulty in the diagnosis of maternal infection, absence of validated prenatal prognostic markers, unavailability of an efficient vaccine and scarcity of data available on the treatment. However, in the last decade, new data have emerged towards better management of this congenital infection, including solid epidemiological data, good evidence for the accuracy of diagnosis of maternal CMV infection and good evidence for the feasibility of predicting the outcome of fetal infection by a combination of fetal imaging and fetal laboratory parameters. There is also some evidence that valaciclovir treatment of mothers carrying an infected fetus is feasible, safe and might be effective. This review provides an update on the evidence for diagnosis, prognosis and treatment of congenital infection in the antenatal period. These suggest a benefit to a proactive approach for prenatal congenital infections.

Congenital Cytomegalovirus Infection: Prognostic Value of Maternal DNAemia at Amniocentesis

BACKGROUND

Human Cytomegalovirus (HCMV) is the most common cause of childhood hearing loss and can lead to neurodevelopmental delay. To date, few studies have examined the correlation between maternal viremia and congenital HCMV infection. The aim of our study was to ascertain if HCMV DNA in the peripheral blood of pregnant women with primary HCMV infection at the time of amniocentesis may have a prognostic value in terms of congenital infection and neonatal symptomatic disease.

METHODS

We performed a prospective observational study of pregnant women referred to our maternal-fetal medicine division with suspected HCMV infection. Primary infection was diagnosed based on seroconversion for HCMV and/or HCMV immunoglobulin M-positive and low or moderate HCMV immunoglobulin G avidity. At the time of amniocentesis, maternal blood samples were collected and analyzed by means of real-time polymerase chain reaction to determine the presence of viral DNAemia. Fetuses and newborns were evaluated for the presence of congenital infection and symptomatic disease.

RESULTS

A total of 239 pregnant women were enrolled; 32 blood samples (13.4%) were positive, and 207 (86.6%) were negative for HCMV DNA. The overall rate of transmission was 23.4%. Fifteen infected patients (26.8%) were symptomatic. Vertical transmission occurred in 14 women (43.8%) with positive and 42 (20.3%) with negative results for HCMV DNAemia (P = .006; odds ratio, 3.06; 95% confidence interval, 1.41-6.64). Symptomatic infection occurred in 6 (42.9%) infected fetuses or newborns from women with and in 9 (21.4%) from women without viral DNAemia (P = .16).

CONCLUSION

Maternal viremia at amniocentesis is associated with a 3-fold greater chance of congenital infection, but it is not correlated with symptomatic disease.

Clinical Implications for Children Born With Congenital Cytomegalovirus Infection Following a Negative Amniocentesis

BACKGROUND

Recently, congenital cytomegalovirus (cCMV) infection was reported irrespective of a negative amniotic fluid prenatal analysis for cytomegalovirus (CMV). The question of whether this phenomenon represents low sensitivity of the test or late development of fetal infection (after amniocentesis) was discussed, but not answered. However, if late transmission is the rule, then infants born with cCMV after negative amniocentesis would be expected to carry better prognosis than those who tested positive.

METHODS

Data of all infants with cCMV infection, followed in 2 pediatric centers from 2006 to 2015, were reviewed. Infant outcome after birth of symptomatic vs asymptomatic disease was compared with infants born after a negative amniocentesis (study group) and those with a positive amniocentesis (control group).

RESULTS

Amniocentesis was performed in 301 pregnancies of our cohort of infants with cCMV and was negative for CMV in 47 (15.6%). There were fewer symptomatic cCMV neonates in the study group than in the control group (4.3% vs 25%; P < .001). Hearing impairment at birth was also less frequent in the study group (2.2% vs 17.4%; P = .012). None of the children in the study group had neurologic sequelae at long-term follow up, compared with 13 (14.1%) in the control group (P < .001).

CONCLUSIONS

Although negative amniocentesis does not exclude cCMV, infants with cCMV born after a negative amniocentesis seldom present with mild clinical symptoms or cerebral ultrasound features at birth. These children also have a very good long-term outcome. Our findings support the theory of a late development of fetal infection, after the time of the amniocentesis.

[Cytomegalovirus infection in pregnancy]

Cytomegalovirus is the main cause of neurosensorial deficit due to a congenital infection. Fetal infection may follow a maternal primary infection or a maternal secondary infection. The diagnosis of maternal primary infection remains tricky because the interpretation of IgG avidity test may be difficult. The diagnosis of maternal secondary infections is impossible with usual routine assays. The virological diagnosis of fetal infection is very reliable with a sensitivity over 90% and a specificity next to 100%. In the context of a proven intrauterine infection, the negative predictive value of ultrasound coupled with fetal brain RMI is over 85%. No antenatal treatment is yet validated, two treatments (hyperimmune therapy and antival therapy) are under evaluation. Six months treatment course with valganciclovir improves audiologic and neurodevelopmental outcomes of symptomatic neonates.

A randomized trial of hyperimmune globulin to prevent congenital cytomegalovirus

BACKGROUND

Congenital infection with human cytomegalovirus (CMV) is a major cause of morbidity and mortality. In an uncontrolled study published in 2005, administration of CMV-specific hyperimmune globulin to pregnant women with primary CMV infection significantly reduced the rate of intrauterine transmission, from 40% to 16%.

METHODS

We evaluated the efficacy of hyperimmune globulin in a phase 2, randomized, placebo-controlled, double-blind study. A total of 124 pregnant women with primary CMV infection at 5 to 26 weeks of gestation were randomly assigned within 6 weeks after the presumed onset of infection to receive hyperimmune globulin or placebo every 4 weeks until 36 weeks of gestation or until detection of CMV in amniotic fluid. The primary end point was congenital infection diagnosed at birth or by means of amniocentesis.

RESULTS

A total of 123 women could be evaluated in the efficacy analysis (1 woman in the placebo group withdrew). The rate of congenital infection was 30% (18 fetuses or infants of 61 women) in the hyperimmune globulin group and 44% (27 fetuses or infants of 62 women) in the placebo group (a difference of 14 percentage points; 95% confidence interval, -3 to 31; P=0.13). There was no significant difference between the two groups or, within each group, between the women who transmitted the virus and those who did not, with respect to levels of virus-specific antibodies, T-cell-mediated immune response, or viral DNA in the blood. The clinical outcome of congenital infection at birth was similar in the two groups. The number of obstetrical adverse events was higher in the hyperimmune globulin group than in the placebo group (13% vs. 2%).

CONCLUSIONS

In this study involving 123 women who could be evaluated, treatment with hyperimmune globulin did not significantly modify the course of primary CMV infection during pregnancy. (Funded by Agenzia Italiana del Farmaco; CHIP ClinicalTrials.gov number, NCT00881517; EudraCT no. 2008-006560-11.).

Management of pregnancies with confirmed cytomegalovirus fetal infection

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

Overview of the diagnosis of cytomegalovirus infection

Cytomegalovirus (CMV) is recognized as the most common congenital viral infection in humans and an important cause of morbidity and mortality in immunocompromised hosts. This recognition of the clinical importance of invasive CMV disease in the setting of immunodeficiency and in children with congenital CMV infection has led to the development of new diagnostic procedures for the rapid identification of CMV. Diagnosis of acute maternal CMV infection by the presence of immunoglobulin (Ig)M and low-avidity IgG requires confirmation of fetal infection, which is typically performed using polymerase chain reaction (PCR) assays for CMV on amniotic fluid. Viral culture of the urine and saliva obtained within the first two weeks of life continues to be the gold standard for diagnosis of congenitally-infected infants. PCR assays of dried blood spots from newborns have been shown to lack sufficient sensitivity for the identification of most neonates with congenital CMV infection for universal screening purposes. However, saliva PCR assays are currently being assessed as a useful screening method for congenital CMV infection. In the immunocompromised host, newer rapid diagnostic assays, such as phosphoprotein 65 antigenemia and CMV real-time PCR of blood or plasma have allowed for preemptive treatment, reducing morbidity and mortality. However, lack of standardized real-time PCR protocols hinders the comparison of data from different centers and the development of uniform guidelines for the management of invasive CMV infections in immunocompromised individuals.

Prevention of maternal cytomegalovirus infection: current status and future prospects

Human cytomegalovirus (CMV) infection is the most common cause of perinatal viral infection in the developed world, resulting in approximately 40,000 congenitally infected infants in the United States each year. Congenital CMV infection can produce varying degrees of neurodevelopmental disabilities. The significant impact of congenital CMV has led the Institute of Medicine to rank development of a CMV vaccine as a top priority. Vaccine development has been ongoing; however no licensed CMV vaccine is currently available. Treatment of pregnant women with CMV hyperimmune globulin has shown promising results, but has not been studied in randomized controlled trials. Education on methods to prevent CMV transmission, particularly among young women of child-bearing age, should continue until a CMV vaccine becomes available. The epidemiology, clinical manifestations, prevention strategies, and treatment of CMV infections are reviewed.

Guidelines on CMV congenital infection

Congenital cytomegalovirus (CMV) infection occurs in 0.6-0.7% of all newborns and is the most prevalent infection-related cause of congenital neurological handicap. Vertical transmission occurs in around 30% of cases, but the fetus is not always affected. Symptomatic newborns at birth have a much higher risk of suffering severe neurological sequelae. Detection of specific IgG and IgM and IgG avidity seem to be the most reliable tests to identify a primary infection but interpretation in a clinical context may be difficult. If a seroconversion is documented or a fetal infection is suspected by ultrasound markers, an amniocentesis should be performed to confirm a vertical transmission. In the absence of a confirmed fetal infection with fetal structural anomalies, a pregnancy termination should be discouraged. Fetal prognosis is mainly correlated to the presence of brain damage. Despite promising results with the use of antiviral drugs and CMV hyperimmune globulin (HIG), results have to be interpreted with caution. Pregnant women should not be systematically tested for CMV during pregnancy. Managing CMV screening should be restricted to pregnancies where a primary infection is suspected or among women at high risk. The magnitude of congenital CMV disease and the value of interventions to prevent its transmission or to decrease the sequelae need to be established before implementing public health interventions. In this paper, aspects of CMV infection in the pregnant woman and her infant are reviewed.