Prevention of Acquisition of Cytomegalovirus Infection in Pregnancy Through Hygiene-based Behavioral Interventions: A Systematic Review and Gap Analysis

Burden of Congenital CMV Infection: A Narrative Review and Implications for Public Health Interventions

Cytomegalovirus causes the most common congenital infection worldwide. With most infants asymptomatic at birth, the few affected may present with variable clinical scenarios, from isolated hearing loss to severe neurologic impairment. Public health interventions include all actions at the health system, community, and individual levels that aim at reducing the burden of congenital Cytomegalovirus. This review examines the literature on maternal and neonatal screening programs in light of current evidence for treatment and the development of vaccines against Cytomegalovirus. Potential biases and benefits of these interventions are outlined, with the objective of increasing awareness about the problem and providing readers with data and critical tools to participate in this ongoing debate.

Exploring the implementation of an educational film within antenatal care to reduce the risk of cytomegalovirus infection in pregnancy: A qualitative study

BACKGROUND

Congenital cytomegalovirus (CMV) infection is a leading cause of sensorineural hearing loss and neuro-disability in childhood. In the absence of a licensed vaccine, adoption of hygiene-based measures may reduce the risk of CMV infection in pregnancy, however these measures are not routinely discussed with pregnant women as part of National Health Service (NHS) antenatal care in the United Kingdom (UK).

METHODS

An exploratory qualitative study was conducted, underpinned by Normalization Process Theory (NPT), to investigate how an educational intervention comprising of a short film about CMV may best be implemented, sustained, and enhanced in real-world routine antenatal care settings. Video, semi-structured interviews were conducted with participants who were recruited using a purposive sample that comprised of midwives providing antenatal care from three NHS hospitals (n = 15) and participants from professional colleges and from organisations or charities providing, or with an interest in, antenatal education or health information in the UK (n = 15).

FINDINGS

Midwives were reluctant to include CMV as part of early pregnancy discussions about reducing the risk of other infections due to lack of time, knowledge and absence of guidance or policies relating to CMV in antenatal education. However, the educational intervention was perceived to be a useful tool to encourage conversations and empower women to manage risk by all stakeholders, which would overcome some identified barriers. Macro-level challenges such as screening policies and lack of official guidelines to legitimise dissemination were identified.

DISCUSSION

Successful implementation of education about CMV as part of routine NHS care in the UK will require an increase in awareness and knowledge about CMV amongst midwives. NPT revealed that 'coherence' and 'cognitive participation' between service members are vital to imbed CMV education in routine practice. 'Collective action' and 'reflexive monitoring' is required to sustain service changes.

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.

Hygiene-based measures for the prevention of cytomegalovirus infection in pregnant women: a systematic review

BACKGROUND

Human Cytomegalovirus (HCMV) is the most frequent congenital infection worldwide causing important sequelae. However, no vaccine or antiviral treatments are currently available, thus interventions are restricted to behavioral measures. The aim of this systematic review was to assess evidence from available intervention studies using hygiene-based measures to prevent HCMV infection during pregnancy.

METHODS

Studies published from 1972 to 2023 were searched in Medline, PsycInfo, and Clinical Trials (PROSPERO, CRD42022344840) according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Methodological quality was assessed by two authors, using ROBE-2 and MINORS.

RESULTS

After reviewing 6 selected articles, the outcome analysis suggested that implementation of hygiene-based interventions during pregnancy prevent, to some extent, the acquisition of congenital HCMV.

CONCLUSIONS

However, these conclusions are based on limited and low-quality evidence available from few studies using this type of intervention in clinical practice. Thus, it would be necessary to perform effective and homogeneous intervention studies using hygiene-based measures, evaluated in high-quality randomized controlled trials (RCTs).

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.

Learning from the experiences of pregnant women participating in a research study investigating human cytomegalovirus shedding: A qualitative study

Transmission of human cytomegalovirus (CMV), from a pregnant woman to her fetus can cause congenital CMV infection, with life-long problems in some infected children. The presence of CMV in an infected individual's bodily fluid is known as shedding. An individual can become infected with CMV through contact with another individual who is shedding CMV in their bodily fluid, and the avoidance of contact with infected fluids may reduce the risk of infection. We explored the experiences of pregnant women taking part in a study investigating CMV shedding, to identify the potential facilitators and barriers towards engaging pregnant women with CMV risk-reduction measures. Twenty pregnant women participated in semi-structured, end-of-study, telephone interviews, analysed using thematic analysis. They participated in an observational study investigating CMV shedding in pregnant women previously infected with CMV living with young children. Participating women considered that CMV testing of themselves and their newborns was a benefit of participation, without raising additional concerns. They identified that their participation was contingent on a balance of convenience and inconvenience, and benefits and risks. Participation increased their awareness of their hygiene-based practices, leading to behavioural modifications that put them in contact with urine and saliva of their children without instructions to do so. These behavioural modifications might interfere with household routines. However, they recognised it to be a time-limited risk-reduction measure, and felt empowered by the knowledge they had gained through study participation and the support they had received from their partners. Participating women gained an increased awareness of their behaviour, resulting in behavioural modification without instructions to do this, in line with previous findings that trial participation can impact on participants' thinking about their behaviour with a possibility to influence change. Maternal research and risk-reduction measures should be centred around being informative, convenient, empowering, and supportive.

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.

Cytomegalovirus infection during pregnancy

Cytomegalovirus (CMV) infection during pregnancy is a global silent problem. Additionally, it is the leading cause of congenital infections, non-genetic sensorineural hearing loss, and neurodevelopmental delays in infants. However, this has barely been recognized globally. This condition lacks adequate attention, which is further emphasized by the lack of awareness among healthcare workers and the general population. The impact of CMV infection is often overlooked because of the asymptomatic nature of its presentation in infected pregnant women and newborns, difficulty in diagnosis, and the perception that infants born to women with pre-existing antibodies against CMV have normal neonatal outcomes. This article highlights the latest information on the epidemiology, transmission, clinical manifestations, and development of CMV infection and its management. We reviewed the pathophysiology and clinical manifestations of CMV infection in pregnant women, diagnostic methods, including screening and prognostic markers, and updates in treatment modalities. Current advancements in research on vaccination and hyperimmunoglobulins with worldwide treatment protocols are highlighted.

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.

The Psychosocial Impact of Congenital Cytomegalovirus on Caregivers and Families: Lived Experiences and Review of the Literature

Caring for a child with congenital cytomegalovirus (cCMV) can be costly for families, not only in terms of out-of-pocket expenses, but also in terms of caregiver time, relationships, career trajectories, and mental health. These additional burdens are sometimes referred to as "spillover effects". As parents of children with cCMV, we, the authors of this article, discuss the impact that cCMV has had on our families. While multiple studies have reported on the epidemiology, prevention, screening, diagnosis, and management of cCMV, there has been minimal research regarding the possible impact on the family unit. In this narrative review, we discuss the various areas of the lives of families and caregivers that may be impacted by raising a child with cCMV. Whether children are minimally or severely affected by the sequelae of cCMV, they and their families merit the progression of awareness of the virus and governmental policies to help end cCMV. As the existing cCMV-specific literature is limited, we correlate studies of other childhood disabilities and find the mutuality experienced by families affected by cCMV.

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.

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.

Experiences of pregnant women and healthcare professionals of participating in a digital antenatal CMV education intervention

Objective

The study aimed to explore the perspectives of participating pregnant women and Health Care Professionals (HCPs) towards receiving and providing cytomegalovirus (CMV) education so that barriers and facilitators towards incorporating CMV in routine antenatal care could be better understood.

Design

This process evaluation phase employed a qualitative design using individual, semi-structured, face-to-face interviews.

Setting

Recruitment and interviews took place within a large teaching hospital from an ethnically diverse area of South-west London

Participants

The study sample included 20 participants: 15 pregnant women, and five HCPs. All participants were involved in a single centre randomized controlled trial of a digital CMV educational intervention in pregnancy.

Findings

Pregnant participants expressed a strong desire to receive information about CMV as part of routine antenatal care. Although HCPs were accepting of the need for CMV education, it was evident that they felt unequipped to provide this; reasons included lack of time, uncertainty about clinical pathways and concern about the potential emotive impact of CMV education. Pregnant women suggested that expressing behaviour changes as risk reduction rather than prevention, made the behaviours feel more achievable and realistic. The support of partners was considered a key factor in the successful adoption of behavioural changes by pregnant women.

Key conclusions and implications for practice

There is an onus on HCPs to consider how CMV can be included as part of antenatal education, with messaging framed as risk reducing rather than prevention.

Changing knowledge, attitudes and behaviours towards cytomegalovirus in pregnancy through film-based antenatal education: a feasibility randomised controlled trial of a digital educational intervention

BACKGROUND

Congenital cytomegalovirus (CMV) is the most common congenital infection globally, however information about CMV is not routinely included in antenatal education in the United Kingdom. This feasibility study aimed to gather the essential data needed to design and power a large randomised controlled trial (RCT) to investigate the efficacy of a digital intervention in reducing the risk of CMV acquisition in pregnancy. In order to do this, we carried out a single-centre RCT, which explored the knowledge, attitudes and risk reduction behaviours in women in the intervention and treatment as usual groups, pre- and post-intervention.

METHODS

CMV seronegative women living with a child less than four years old, receiving antenatal care at a single UK tertiary centre, were randomised to the digital intervention or 'treatment as usual' groups. Participants completed questionnaires before the digital intervention and after and at 34 gestational weeks, and responses within groups and between groups were compared using tailored randomisation tests. CMV serology was tested in the first trimester and at the end of pregnancy.

RESULTS

Of the 878 women screened, 865 samples were analysed with 43% (n = 372) being CMV seronegative and therefore eligible to take part in the RCT; of these, 103 (27.7%) women were enrolled and 87 (84%) of these completed the study. Most participants (n = 66; 64%) were unfamiliar with CMV at enrolment, however at 34 gestational weeks, women in the intervention group (n = 51) were more knowledgeable about CMV compared to the treatment as usual group (n = 52) and reported engaging in activities that may increase the risk of CMV transmission less frequently. The digital intervention was highly acceptable to pregnant women. Overall, four participants seroconverted over the course of the study: two from each study group.

CONCLUSIONS

A large multi-centre RCT investigating the efficacy of a CMV digital intervention is feasible in the United Kingdom; this study has generated essential data upon which to power such a study. This single-centre feasibility RCT demonstrates that a digital educational intervention is associated with increase in knowledge about CMV and can result in behaviour change which may reduce the risk of CMV acquisition in pregnancy.

TRIAL REGISTRATION

Clinicaltrials.gov, NCT03511274 , Registered 27.04.18, http://www.Clinicaltrials.gov.

Congenital Cytomegalovirus Infection Burden and Epidemiologic Risk Factors in Countries With Universal Screening: A Systematic Review and Meta-analysis

IMPORTANCE

Congenital cytomegalovirus (cCMV) infection is the most common congenital infection and the leading acquired cause of developmental disabilities and sensorineural deafness, yet a reliable assessment of the infection burden is lacking.

OBJECTIVES

To estimate the birth prevalence of cCMV in low- and middle-income countries (LMICs) and high-income countries (HICs), characterize the rate by screening methods, and delineate associated risk factors of the infection.

DATA SOURCES

MEDLINE/PubMed, Scopus, and Cochrane Database of Systematic Reviews databases were searched from January 1, 1960, to March 1, 2021, and a total of 1322 studies were identified.

STUDY SELECTION

Studies that provided data on the prevalence of cCMV derived from universal screening of infants younger than 3 weeks were included. Targeted screening studies were excluded.

DATA EXTRACTION AND SYNTHESIS

Preferred Reporting Items for Systematic Reviews and Meta-analyses guideline was followed. Extraction was performed independently by 3 reviewers. Quality was assessed using the Newcastle-Ottawa Scale for cohort studies. Random-effects meta-analysis was undertaken. Metaregression was conducted to evaluate the association of sociodemographic characteristics, maternal seroprevalence, population-level HIV prevalence, and screening methods with the prevalence of cCMV.

MAIN OUTCOMES AND MEASURES

Birth prevalence of cCMV ascertained through universal screening of infants younger than 3 weeks for CMV from urine, saliva, or blood samples.

RESULTS

Seventy-seven studies comprising 515 646 infants met the inclusion criteria from countries representative of each World Bank income level. The estimated pooled overall prevalence of cCMV was 0.67% (95% CI, 0.54%-0.83%). The pooled birth prevalence of cCMV was 3-fold greater in LMICs (1.42%; 95% CI, 0.97%-2.08%; n = 23 studies) than in HICs (0.48%; 95% CI, 0.40%-0.59%, n = 54 studies). Screening methods with blood samples demonstrated lower rates of cCMV than urine or saliva samples (odds ratio [OR], 0.38; 95% CI, 0.23-0.66). Higher maternal CMV seroprevalence (OR, 1.19; 95% CI, 1.11-1.28), higher population-level HIV prevalence (OR, 1.22; 95% CI, 1.05-1.40), lower socioeconomic status (OR, 3.03; 95% CI, 2.05-4.47), and younger mean maternal age (OR, 0.85; 95% CI, 0.78-0.92, older age was associated with lower rates) were associated with higher rates of cCMV.

CONCLUSIONS AND RELEVANCE

In this meta-analysis, LMICs appeared to incur the most significant infection burden. Lower rates of cCMV were reported by studies using only blood or serum as a screening method.

Cytomegalovirus Infection in Pregnancy: Prevention, Presentation, Management and Neonatal Outcomes

Congenital cytomegalovirus (cCMV) is the most common congenital infection in the United States, with 1 of 200 live births affected. It is the leading viral cause of intrauterine fetal demise and miscarriage. It is a common cause of neonatal hearing loss, second only to genetic factors. Yet, health care provider awareness remains low. The purpose of this article is to provide a brief overview of the epidemiology, presentation, diagnosis, and treatment of antenatal cytomegalovirus (CMV) infection and cCMV in the neonate. Maternal CMV infection in pregnancy often presents with mild cold-like symptoms or is asymptomatic. The virus can be vertically transmitted to a growing fetus, the risk of transmission and severity of fetal impact varying by timing of exposure during pregnancy. Most neonates born with cCMV show no signs at birth, yet 15% to 25% will have long-term adverse neurodevelopmental conditions. Misconceptions that cCMV cannot be prevented or that neonates born without signs of the disease will be unaffected are common. Evidence supporting antenatal education around behavioral change to lower a woman's risk of acquiring CMV during pregnancy is mounting. CMV infection during pregnancy should be co-managed with a maternal-fetal medicine specialist. There is early evidence for the use of antiviral medication in reducing risk of vertical transmission. Identification of cCMV during pregnancy may help ensure the neonate receives timely treatment after birth. Midwives can play an important role in providing antenatal education about cCMV risk reduction and in initiating a diagnostic evaluation when there is clinical suspicion.