Delayed-onset Hearing Loss Research Articles

Targeted genome editing restores auditory function in adult mice with progressive hearing loss caused by a human microRNA mutation.

Mutations in microRNA-96 (MIR96) cause autosomal dominant deafness-50 (DFNA50), a form of delayed-onset hearing loss. Genome editing has shown efficacy in hearing recovery through intervention in neonatal mice, yet editing in the adult inner ear is necessary for clinical applications, which has not been done. Here, we developed a genome editing therapy for the MIR96 mutation 14C>A by screening different CRISPR systems and optimizing Cas9 expression and the sgRNA scaffold for efficient and specific mutation editing. AAV delivery of the KKH variant of Staphylococcus aureus Cas9 (SaCas9-KKH) and sgRNA to the cochleae of presymptomatic (3-week-old) and symptomatic (6-week-old) adult Mir9614C>A/+ mutant mice improved hearing long term, with efficacy increased by injection at a younger age. Adult inner ear delivery resulted in transient Cas9 expression without evidence of AAV genomic integration, indicating the good safety profile of our in vivo genome editing strategy. We developed a dual-AAV system, including an AAV-sgmiR96-master carrying sgRNAs against all known human MIR96 mutations. Because mouse and human MIR96 sequences share 100% homology, our approach and sgRNA selection for efficient and specific hair cell editing for long-term hearing recovery lay the foundation for the development of treatment for patients with DFNA50 caused by MIR96 mutations.

Pediatric tracheostomy audiometric outcomes - A quality improvement initiative.

Pediatric tracheostomy patients disproportionately experience hearing loss and are at risk for delayed identification due to their medical complexity. Nonetheless, protocols to monitor hearing in these children are lacking. This quality improvement (QI) initiative aimed to increase the rates of audiometric testing within 12 months of pediatric tracheostomy placement. A retrospective cohort study included children who underwent tracheostomy under 18 months of age between 2012 and 2020. Rates of audiometric assessments before and after QI project implementation (2015) were reported along with hearing loss characteristics. A total of 253 children met inclusion. Before project initiation (2012-2014), 32% of children (28/87) obtained audiometric testing within 12 months after tracheostomy. During the first three years of implementation (2015-2017), 39% (38/97) were tested, while 55% (38/69) were tested during the subsequent three years (2018-2020) (P=.01). A passing newborn hearing screen was obtained for 70% of the 210 children with a recorded result, and 198 survived at least 12 months to receive audiometric testing at a median of 11.3 months (IQR: 6.2-22.8) after tracheostomy. Hearing loss was identified for 44% of children (N=88), of which 42 children initially passed newborn hearing screen. A second assessment was obtained for 62% of children (123/198) at a median of 11.3 months (IQR: 4.5-17.5) after the initial test. In this group, 23% with a previously normal audiometric exam were found to have hearing loss (15/66). QI initiatives designed to monitor hearing loss in children with a tracheostomy can result in improved rates of audiometric assessments. This population has disproportionately high rates of hearing loss, including delayed onset hearing loss making audiometric protocols valuable to address speech and language development delays.

American Academy of Audiology Position Statement on Early Identification of Cytomegalovirus in Newborns.

The American Academy of Audiology recommends early identification of congenital cytomegalovirus (cCMV) through screening to allow for appropriate early diagnosis, intervention, and monitoring for congenital, progressive, and delayed-onset hearing loss in infants with cCMV.Early identification of cCMV is a valuable component in the diagnostic evaluation of infants with sensorineural hearing loss. The Academy recognizes the important role audiologists serve as clinical care providers and educators and advocates for early identification and audiological management of infants with cCMV.

Hearing Screening in Pediatric Primary Care.

1. Jordan K. Yoeli, MD*,† 2. Daniel Nicklas, MD*,† 1. *Children’s Hospital Colorado, Aurora, CO 2. †University of Colorado, Aurora, CO Screening for congenital and acquired deafness and hearing loss (HL) represents a significant responsibility for clinicians in all newborn units and medical homes. Approximately 1 to 3 infants of 1,000 born in a well infant nursery setting and 2 to 4 of 100 born in a NICU have significant bilateral HL. Outcomes in various developmental domains depend on the early recognition and subsequent intervention for HL. Developmental delay is present in 30% to 40% of children with HL; the goal of hearing screening (HS) and prompt intervention is to optimize a child’s language acquisition, cognitive development, literacy, social-emotional maturity and academic success. This article reviews the most up-to-date standards and practices to aid medical providers in the early detection and intervention for pediatric HL. In the United States, universal screening begins in the neonatal period. According to the American Academy of Pediatrics (AAP) Joint Commission on Infant Hearing (JCIH), all infants should be screened for congenital HL before 1 month of age. Most infants are screened in nursery or NICU settings, except for those born outside of a medical facility. For the latter population or for infants with no documented HS, screening should be completed by the medical home before 1 month of age. In a well nursery setting, most HSs are performed by otoacoustic emission (OAE) testing. During an OAE screen, a sensitive microphone in the ear canal records the cochlear responses (“acoustic emissions”) to acoustic stimuli, thereby testing the peripheral auditory system from the outer/middle ear (conduction zones) to the cochlear outer hair cells (sensory organ). A “pass” indicates that hearing is functional to the level of …

A Novel p.Tyr129His Variant in SIX1 Leads to Dominant, Delayed-onset Hearing Loss with Possible Association with Congenital Anosmia

A Novel p.Tyr129His Variant in SIX1 Leads to Dominant, Delayed-onset Hearing Loss with Possible Association with Congenital Anosmia

Functional Role of Class III Myosins in Hair Cells.

Cytoskeletal motors produce force and motion using the energy from ATP hydrolysis and function in a variety of mechanical roles in cells including muscle contraction, cargo transport, and cell division. Actin-based myosin motors have been shown to play crucial roles in the development and function of the stereocilia of auditory and vestibular inner ear hair cells. Hair cells can contain hundreds of stereocilia, which rely on myosin motors to elongate, organize, and stabilize their structure. Mutations in many stereocilia-associated myosins have been shown to cause hearing loss in both humans and animal models suggesting that each myosin isoform has a specific function in these unique parallel actin bundle-based protrusions. Here we review what is known about the classes of myosins that function in the stereocilia, with a special focus on class III myosins that harbor point mutations associated with delayed onset hearing loss. Much has been learned about the role of the two class III myosin isoforms, MYO3A and MYO3B, in maintaining the precise stereocilia lengths required for normal hearing. We propose a model for how class III myosins play a key role in regulating stereocilia lengths and demonstrate how their motor and regulatory properties are particularly well suited for this function. We conclude that ongoing studies on class III myosins and other stereocilia-associated myosins are extremely important and may lead to novel therapeutic strategies for the treatment of hearing loss due to stereocilia degeneration.

Hearing Impairment in Infants with Hypoxic Ischemic Encephalopathy Treated with Hypothermia.

Therapeutic hypothermia acts as the standard of care for infants with moderate to severe hypoxic ischemic encephalopathy (HIE). A proportion of neonates who undergo hypothermia due to HIE have shown to develop various degrees of hearing impairment. Analyzing and identifying infants at high risk of developing hearing difficulties is fundamental for early intervention of such auditory complications. The aim was to assess clinical factors in the development of hearing impairment following therapeutic hypothermia in HIE infants. A retrospective analysis was performed on infants hospitalized in our neonatology department in Poznan University of Medical Sciences, Poland. All infants experienced moderate to severe HIE, and were treated with therapeutic hypothermia. Risk factors for hearing impairment were identified in all infants included in the study. Clinical data during hospital stay and follow-up hearing status were analyzed. A total of 87 HIE infants were included in the study. Seventy-six infants (40 male and 36 female) had otoacoustic emission (OAE) examination following birth, of which 14 (18.4%) demonstrated abnormal (positive) results. Infants with abnormal OAE results had significantly lower blood pH (6.86 ± 0.16, p = 0.001) and base excess (BE) (-22.46 ± 2.59, p = 0.006). Of the 49 infants who returned for follow-up assessment, 4 (8.2%) were diagnosed with sensorineural bilateral hearing impairment (1 infant, mild [<40 dB], 2 moderate [41-70 dB], and 1 profound [>90 dB]). The biochemical analysis following birth revealed significantly lower umbilical BE levels (-23.90 ± 4.99, p = 0.041) and higher lactate levels (160.67 ± 4.93, p = 0.019) in the infants with eventual sensorineural hearing deficit. Infants with moderate or severe HIE are at risk of delayed onset hearing loss. Diligent efforts to monitor auditory status are required, even if early screening results for hearing are insignificant. Exploring biochemical parameters, such as lactate, BE, and blood pH, can prove beneficial in identifying HIE infants at risk of developing a hearing impairment.

Análisis de los factores de riesgo y del seguimiento de la hipoacusia de inicio tardío durante 25 años de cribado auditivo

Introducción: En 1972 el Joint Committee on Infant Hearing (JCIH) de EEUU, propone la evaluación audiológica precoz de los niños que nacen con determinados “factores de riesgo” (FR), al comprobarse que asocian hipoacusia con mayor frecuencia. Tras hacerse realidad el cribado auditivo universal, se sigue indicando la conveniencia de un seguimiento de los recién nacidos (RN) con FR de hipoacusia permanente posnatal o de inicio tardío (HPP).&#x0D; Material y métodos: Tras aplicar durante 25 años un programa de cribado auditivo neonatal, en el Hospital Clínico Universitario (HCU) de Valladolid (España), hemos analizado la incidencia de los FR y el rendimiento obtenido con el seguimiento de los niños que presentaban FR de hipoacusia tardía al nacimiento.&#x0D; Resultados: De los 27.649 RN evaluados, detectamos un 0,25 por mil de HPP, que representa el 8% de las hipoacusias congénitas y el 0,65% de los RN con FR. En nuestro medio, los FR con mayor prevalencia de HPP son, los antecedentes familiares de hipoacusia y la presencia de malformaciones o síndromes que asocian hipoacusia. La HPP es fundamentalmente bilateral, de tipo neurosensorial y en un elevado porcentaje (23%) de grado leve.&#x0D; Discusión y Conclusiones: El seguimiento de los factores de riesgo propuestos por el JCIH como indicadores de HPP, no resulta ni eficaz ni económicamente rentable; sin embargo, dada la importancia de la HPP, consideramos que en el momento actual debería mantenerse el de aquellos FR que tengan una prevalencia elevada de hipoacusia y dado que, la mitad de las hipoacusias posnatales no asocian FR, añadir a este seguimiento, la realización de un estudio neonatal de pruebas genéticas de hipoacusia junto al análisis de la presencia de citomegalovirus.

Status of early hearing detection and intervention in South Korea: a nationwide population-based study of national infant health checkup

The aim of this study was to evaluate the status of early hearing detection and intervention after newborn hearing screening (NHS) in South Korea. A retrospective review of Korean national health insurance service data of all infants receiving the 4-month old national infant health checkup between 2010 and 2016 from a nationwide population-based database was conducted. Based on the results of the NHS-administered hearing questionnaires as part of the national infant health checkup, individuals were classified into “pass” (1,730,615 infants) or “refer” (10,941 infants) groups. Next, an analysis was conducted of age and the frequencies of tracking audiologic tests and surgeries of the middle ear (ME) and cochlear implants (CI). Diagnostic auditory brainstem response and audiometry, and surgeries of ME and CI were significantly performed more and earlier in the refer group compared with the pass group. For infants in the pass group who were presumed to have delayed or acquired hearing loss, the time of the first audiology tests and CI surgery was significantly delayed compared to those in the refer group; the average ages for first CI were 37 and 52 months in the refer group and pass group, respectively. Therefore, for early detection of delayed-onset hearing loss, regular hearing screening programs should be considered throughout the preschool ages.

Electrocochleography in Cochlear Implant Users with Residual Acoustic Hearing: A Systematic Review.

(1) Objectives: This study reviews the use of electrocochleography (ECoG) as a tool for assessing the response of the peripheral auditory system and monitoring hearing preservation in the growing population of cochlear implant (CI) users with preserved hearing in the implanted ear. (2) Methods: A search was conducted in PubMed and CINAHL databases up to August 2020 to locate articles related to the ECoG measured during or after the cochlear implant (CI) surgery for monitoring purposes. Non-English articles, animal studies, literature reviews and editorials, case reports, and conference papers were excluded. The quality of studies was evaluated using the National Institute of Health (NIH) “Study Quality Assessment Tool for Case Series Studies”. (3) Results: A total 30 articles were included for the systematic review. A total of 21 articles were intraoperative ECoG studies, while seven articles were postoperative studies. Two studies were conducted ECoG both during and after the surgery. Intraoperative ECoG studies focused on monitoring changes in ECoG response amplitudes during and/or after electrode insertion and predicting the scalar location of the electrode array. Postoperative ECoG studies focused on using the ECoG measurements to estimate behavioral audiometric thresholds and monitor pathophysiological changes related to delayed onset hearing loss postimplant. (4) Conclusions: ECoG is feasible to provide real-time feedback intraoperatively and has a potential clinical value to monitor the status of hearing preservation postoperatively in this CI population with residual acoustic hearing.

Prevalence and risk factors for delayed-onset hearing loss in early childhood: A population-based observational study in Okayama Prefecture, Japan

ObjectivesThe aim of this study was to retrospectively document prevalence rates of delayed-onset hearing loss (DOHL) under 7 years old after passing the newborn hearing screening (NHS) program using its database in Okayama Prefecture, as well as records from Okayama Kanariya Gakuen (OKG, Auditory Center for Hearing Impaired Children, Okayama Prefecture, Japan). We explored the percentage of children with DOHL among all children who underwent the NHS and surveyed risk factors abstracted from their clinical records. MethodsWe collected data of 1171 children, who first visited OKG from April 2006 to March 2018. DOHL children were defined as bilaterally hearing-impaired children who were diagnosed under 7 years old after passing the NHS at birth. Based on the medical records, we investigated age at diagnosis, hearing levels, and risk factors. As population-based data of 168,104 children, the percentage of DOHL subjects was retrospectively calculated among the total number of children who underwent the NHS in Okayama Prefecture from April 2005 to March 2017. ResultsDuring the period, we identified 96 children with bilateral DOHL, of which 34 children had failed the NHS unilaterally and 62 had passed the NHS bilaterally. Among all children who underwent the NHS in Okayama Prefecture, the prevalence rate of DOHL in unilaterally referred infants was 5.2%, and 0.037% in bilaterally passed children. The prevalence of bilateral DOHL was 0.057% overall. Unilaterally referred children with DOHL were diagnosed at an average of 13.9 months, while bilaterally passed children with DOHL were diagnosed at an average of 42.3 months. Approximately 59.4% of children with DOHL had risk factors, among which family history of hearing loss was the most frequent. ConclusionWe propose the first English report of DOHL prevalence in the prefecture population in Japann, which is among the largest community-based population ever reported. The NHS is not a perfect strategy to detect all early-childhood hearing loss; therefore, careful assessment of hearing throughout childhood is recommended, especially in children with risk factors of hearing loss. Further interventional strategies must be established, such as regular hearing screening in high-risk children and assessments of hearing and speech/language development in public communities and nursery schools.

Congenital CMV-Associated Hearing Loss: Can Brain Imaging Predict Hearing Outcome?

Congenital cytomegalovirus (cCMV) infection is the leading cause of nonhereditary sensorineural hearing loss in childhood and is also associated with CNS abnormalities. The main objective is to investigate the prognostic value of neonatal cranial ultrasound (cUS) and cranial magnetic resonance imaging (cMRI) in predicting long-term hearing outcome in a large cohort of cCMV-infected symptomatic and asymptomatic patients. Data were prospectively collected from a multicentre Flemish registry of children with cCMV infection born between 2007 and 2016. Neonatal cUS and cMRI scans were examined for lesions related to cCMV infection. Audiometric results at different time points were analyzed. The imaging and audiometric results were linked and diagnostic values of cUS and cMRI were calculated for the different hearing outcomes. We were able to include 411 cCMV patients, of whom 40% was considered symptomatic at birth. Cranial ultrasound abnormalities associated with cCMV infection were found in 76 children (22.2% of the cUS scans), whereas cMRI revealed abnormalities in 74 patients (26.9% of the cMRI scans). A significant relation could be found between the presence of cUS or cMRI abnormalities and hearing loss at baseline and last follow-up. Cranial ultrasound and cMRI findings were not significantly correlated with the development of delayed-onset hearing loss. Specificity and sensitivity of an abnormal cUS to predict hearing loss at final follow-up were 84% and 43%, respectively compared with 78% and 39% for cMRI. Normal cUS and cMRI findings have a negative predictive value of 91% and 92%, respectively, for the development of delayed-onset hearing loss. Neuroimaging evidence of CNS involvement in the neonatal period is associated with the presence of hearing loss in children with a cCMV infection. Imaging abnormalities are not predictive for the development of delayed-onset hearing loss.

Etiology of Prelingual Hearing Loss in the Universal Newborn Hearing Screening Era: A Scoping Review.

To conduct a scoping review on etiologic investigation of prelingual hearing loss among children <2 years of age in the era of universal newborn hearing screening (UNHS). PubMed, Embase, PsycInfo, CINAHL, and Cochrane Library databases. We searched for articles published from January 1, 1998, to February 19, 2020. We reviewed studies that (1) included children identified with either congenital or delayed-onset hearing loss before 2 years of age among cohorts who had undergone UNHS and (2) investigated ≥1 etiologies of hearing loss. We defined hearing loss as congenital when confirmed after UNHS failure and as delayed onset when diagnosed after ≥1 assessments with normal hearing. Among 2069 unique citations, 115 studies met criteria for full-text assessment, and 20 met our inclusion criteria. Six studies tested children diagnosed with hearing loss for genetic etiology, 9 for congenital cytomegalovirus (CMV) infection, and 5 for both. Among 1787 children with congenital hearing loss and etiologic investigation, 933 (52.2%) were tested for genetic mutations and 1021 (57.1%) for congenital CMV infection. The proportion of congenital hearing loss cases attributable to genetic etiology ranged between 7.7% and 83.3% and to congenital CMV infection between 0.0% and 32.0%. Data are lacking on the identification and etiology of delayed-onset hearing loss in children <2 years of age in the UNHS era. The proportion of congenital hearing loss cases attributable to genetic etiologies and congenital CMV infection appears to vary widely.

Adherence to follow-up recommendations for babies at risk for pediatric hearing loss

ObjectiveThe purpose of this retrospective study was to evaluate the families’ compliance with recommendations for continued monitoring of babies with high-risk factors for hearing loss. MethodsHearing screening and follow-up results from 604 babies were tracked across a five-year period. Bivariate analysis, including chi-square analysis, t-tests, and one-way analyses of variance were conducted to test whether various factors predicted likelihood of follow up. ResultsAlthough 86% of the babies returned for the initial follow-up appointment, few completed the protocol or were diagnosed with hearing loss (10.3%). Excluding the babies who never returned, the average age for initial assessment was near the recommended 3-month target (3.5 months). However, babies were last seen at 9.4 months on average, which is earlier than recommended. Some factors positively predicted follow-up: receipt of ototoxic medication, hyperbilirubinemia requiring transfusion, ECMO, syndromes associated with hearing loss, craniofacial anomalies, and passing the newborn hearing screening. Others were negatively predictive: NICU stay >5 days, younger maternal age, and failing the newborn screening. There was no relationship between the results of the last test and whether the families continued with monitoring. Babies with risks categorized as more likely to be associated with delayed onset hearing loss were more often late to the initial follow up, but also followed up for a longer period of time. ConclusionsThese results demonstrate the need to focus on the barriers unique to babies with risk factors for late onset/progressive hearing loss in addition to those barriers that generally affect loss to follow up. Tools for parental engagement are recommended.

Childhood delayed-onset hearing loss deserves close attention

Childhood delayed-onset hearing loss deserves close attention

Research progress on the etiology of delayed-onset hearing loss in children

Newborn hearing screening is an effective method for early detection of hearing loss, however, it is not able to detect delayed-onset hearing loss. By exploring the etiology of delayed-onset hearing loss in children, it can provide a clinical basis for early detection of delayed-onset hearing loss. Mutations in SLC26A4, mitochondrial, GJB2 and other genes, enlarged vestibular aqueduct, congenital cytomegalovirus infection, extracorporeal membrane oxygenation, and auditory neuropathy et al were more commonly reported risk factors. In this paper, the risk factors related to delayed-onset hearing loss, which are divided into 5 categories: genetic mutation, abnormal inner ear malformation, perinatal factors, auditory neuropathy and no identifiable cause, are reviewed and analyzed.

High Risk Factors Associated With Early Childhood Hearing Loss: A 3-Year Review.

In this study, we examined the association between risk factors for hearing loss and early childhood hearing status (normal hearing, congenital hearing loss, or delayed-onset hearing loss). Follow-up rates of audiologic care following passed or referred birth screens for children with risk factors were also examined. A retrospective data review was completed on 115,039 children born from 2010 to 2012. Data analyses included prevalence rates, odds ratios, and Fisher exact tests of statistical significance. Ninety percent of children were born with no risk factors for hearing loss; of those, 99.9% demonstrated normal hearing by 3 years of age. Of the 10% of children born with risk factors, 96.3% demonstrated normal hearing by age 3, 1.4% presented with congenital hearing loss, and 2.3% demonstrated permanent hearing loss by age 3. Factors that placed children at the highest risk of congenital hearing impairment were neurodegenerative disorders, syndromes, and congenital infections. Factors that placed children at the highest risk of developing permanent postnatal hearing loss were congenital cytomegalovirus, syndromes, and craniofacial anomalies. Certain risk factors place a child at significantly greater risk of congenital hearing impairment or developing permanent hearing loss by age 3. Follow-up diagnostic testing should remain a priority for children with certain risk factors for hearing loss.

Delayed changes in auditory status in cochlear implant users with preserved acoustic hearing

This retrospective review explores delayed-onset hearing loss in 85 individuals receiving cochlear implants designed to preserve acoustic hearing at the University of Iowa Hospitals and Clinics between 2001 and 2015. Repeated measures of unaided behavioral audiometric thresholds, electrode impedance, and electrically evoked compound action potential (ECAP) amplitude growth functions were used to characterize longitudinal changes in auditory status. Participants were grouped into two primary categories according to changes in unaided behavioral thresholds: (1) stable hearing or symmetrical hearing loss and (2) delayed loss of hearing in the implanted ear. Thirty-eight percent of this sample presented with delayed-onset hearing loss of various degrees and rates of change. Neither array type nor insertion approach (round window or cochleostomy) had a significant effect on prevalence. Electrode impedance increased abruptly for many individuals exhibiting precipitous hearing loss; the increase was often transient. The impedance increases were significantly larger than the impedance changes observed for individuals with stable or symmetrical hearing loss. Moreover, the impedance changes were associated with changes in behavioral thresholds for individuals with a precipitous drop in behavioral thresholds. These findings suggest a change in the electrode environment coincident with the change in auditory status. Changes in ECAP thresholds, growth function slopes, and suprathreshold amplitudes were not correlated with changes in behavioral thresholds, suggesting that neural responsiveness in the region excited by the implant is relatively stable. Further exploration into etiology of delayed-onset hearing loss post implantation is needed, with particular interest in mechanisms associated with changes in the intracochlear environment.

Hearing in Children with Congenital Cytomegalovirus Infection: Results of a Longitudinal Study

To evaluate hearing outcome, to characterize the nature of symptomatic and asymptomatic congenital cytomegalovirus (cCMV) infection and associated hearing loss, and to compare results with data from previous studies. A prospective multicenter registry was set up in 2007. Six centers participated in the development of a standardized protocol for diagnosis, treatment, and follow-up. Data were gathered in an online registry. Children (n=379) with a documented cCMV infection and at least 2 separate audiologic evaluations were included. Audiometric results from a multicenter cohort study of children with cCMV infection with longitudinal observation were examined. Results from 123 children with a symptomatic and 256 children with an asymptomatic cCMV infection were analyzed. In the group with symptomatic cCMV, 63% had hearing loss, compared with 8% in the group with asymptomatic cCMV. Delayed-onset hearing loss occurred in 10.6% of symptomatic cCMV and in 7.8% of asymptomatic cCMV. In the group with symptomatic cCMV, 29.3% of children used some kind of hearing amplification; 1.6% in the group with asymptomatic cCMV used hearing amplification. Symptomatic and asymptomatic cCMV infections are a major cause of hearing loss in childhood. Reliable estimates of the long-term outcome of cCMV infection are mandatory to increase vigilance, especially among pregnant women and to draw attention to preventive measures, vaccine development, and prenatal and postnatal therapy. Universal screening of newborns for cCMV infection should be initiated and combined with longitudinal audiometric follow-up.

Congenital cytomegalovirus infection in pregnancy: a review of prevalence, clinical features, diagnosis and prevention.

Human cytomegalovirus (CMV) is under-recognised, despite being the leading infectious cause of congenital malformation, affecting ~0.3% of Australian live births. Approximately 11% of infants born with congenital CMV infection are symptomatic, resulting in clinical manifestations, including jaundice, hepatosplenomegaly, petechiae, microcephaly, intrauterine growth restriction and death. Congenital CMV infection may cause severe long-term sequelae, including progressive sensorineural hearing loss and developmental delay in 40-58% of symptomatic neonates, and ~14% of initially asymptomatic infected neonates. Up to 50% of maternal CMV infections have nonspecific clinical manifestations, and most remain undetected unless specific serological testing is undertaken. The combination of serology tests for CMV-specific IgM, IgG and IgG avidity provide improved distinction between primary and secondary maternal infections. In pregnancies with confirmed primary maternal CMV infection, amniocentesis with CMV-PCR performed on amniotic fluid, undertaken after 21-22 weeks gestation, may determine whether maternofetal virus transmission has occurred. Ultrasound and, to a lesser extent, magnetic resonance imaging are valuable tools to assess fetal structural and growth abnormalities, although the absence of fetal abnormalities does not exclude fetal damage. Diagnosis of congenital CMV infection at birth or in the first 3 weeks of an infant's life is crucial, as this should prompt interventions for prevention of delayed-onset hearing loss and neurodevelopmental delay in affected infants. Prevention strategies should also target mothers because increased awareness and hygiene measures may reduce maternal infection. Recognition of the importance of CMV in pregnancy and in neonates is increasingly needed, particularly as therapeutic and preventive interventions expand for this serious problem.