A novel NONO nonsense variant in a fetus with renal abnormalities.

At 16 + 6-weeks a fetal scan performed in the second pregnancy of a 42 y.o. woman identified a right multicystic dysplastic kidney, left renal agenesis, absent urinary bladder, myocardial hypertrophy, increased nuchal fold, a single umbilical artery, and oligohydramnios. Trio exome sequencing analysis detected a novel pathogenic NONO variant. Postmortem examination after the termination of pregnancy confirmed the ultrasound findings and also revealed pulmonary hypoplasia, retrognathia and low-set ears. The variant was a novel de novo hemizygous pathogenic loss-of-function variant in NONO [NM_007363.5], associated with a rare X-linked recessive neurodevelopmental disorder, named intellectual developmental disorder, X-linked syndromic 34 (OMIM#300967). The postnatal characteristic features of this disorder include intellectual disability, developmental delay, macrocephaly, structural abnormalities involving the corpus callosum and/or cerebellum, left ventricular noncompaction and other congenital heart defects. In the prenatal setting, the phenotype has been poorly described, with all described cases presenting with heart defects. This case highlights the need of further clinical delineation to include renal abnormalities in the prenatal phenotype spectrum.

Expert Pathology for Gestational Trophoblastic Disease: Towards an International Multidisciplinary Team Meeting.

BACKGROUND: Gestational trophoblastic disease (GTD), comprising hydatidiform moles and gestational trophoblastic tumours, is extremely rare. Exact diagnosis is crucial to indicate the appropriate treatment and to prevent complications. The scarcity and variability in the number of cases available for reporting, lack of specialised training in GTD, and non-existence of refresher courses implies that the pathologist dealing with these rare and, at times, extremely challenging cases is not completely confident in their diagnosis. OBJECTIVES: The objective of this study was to explore the benefits of implementation of an international multidisciplinary conference (virtual) to aid diagnosis of difficult cases and support clinical management of GTD. METHODS: A short survey was circulated to all 46 members of the EOTTD pathology and genetics working party and further spread to other colleagues who practice GTD. This showed that the pathologists and geneticists working with GTD patients do not feel adequately supported and equipped with dealing with these rare diseases. OUTCOME: Virtual cross-border multidisciplinary team meetings (MDTs) were initiated in April 2022, bringing together participants from 11 European countries on a bi-yearly basis. Mean numbers of 3 patients are discussed during the MDTs followed by 3-4 quality assessment cases. A participant survey was conducted at the end of virtual meeting with an average satisfaction rate of 9.5. The pathologists felt supported and benefited from networking and clinical collaboration. CONCLUSIONS AND OUTLOOK: This international MDT continues to provide support in managing the uncertainty with difficult and rare cases and enhances the pathologists training and experience. The frequency of meetings and the number of cases discussed per meeting will be increased in 2023 given the positive response. This will empower individuals and organisations to work together and improve diagnosis and the prognosis for these young patients.

Microbial profile of placentas from Tanzanian mothers with adverse pregnancy outcomes and periodontitis.

AIM: To investigate microbial profiles in placentas from a population of East African mothers with and without adverse pregnancy outcomes and with regard to their periodontal status. MATERIAL AND METHODS: Thirty-six placentas from pregnant women from Tanzania were classified into three groups according to both pregnancy outcome and the mother's periodontal health. The microbial composition in each group was then compared using 16S rRNA metagenomics. Additionally, placenta specimens were analyzed histologically for chorioamnionitis by a single pathologist blinded to the clinical data. RESULTS: The greatest differences were observed in the group of mothers with periodontitis. The microbial load was low in all three groups of mothers. Periodontitis had a notable influence on the structure of the placental microbiota. Three phyla and 44 genera were associated with periodontitis, whereas only the Tenericutes phylum was associated with the adverse pregnancy variable. Streptococcaceae and Mycoplasmataceae families were associated with both periodontitis and adverse pregnancy outcomes. Finally, although the differences for chorioamnionitis were not significant, this intra-amniotic infection was more frequent in the placentas from mothers with periodontitis. CONCLUSIONS: Our findings suggest that bacteria from the oral cavity may involve the feto-placental unit, and that periodontitis may be a modulating factor of the microbial community present in this niche.

Diffuse trophoblast damage is the hallmark of SARS-CoV-2-associated fetal demise.

Placental pathology in SARS-CoV-2-infected pregnancies seems rather unspecific. However, the identification of the placental lesions due to SARS-CoV-2 infection would be a significant advance in order to improve the management of these pregnancies and to identify the mechanisms involved in a possible vertical transmission. The pathological findings in placentas delivered from 198 SARS-CoV-2-positive pregnant women were investigated for the presence of lesions associated with placental SARS-CoV-2 infection. SARS-CoV-2 infection was investigated in placental tissues through immunohistochemistry, and positive cases were further confirmed by in situ hybridization. SARS-CoV-2 infection was also investigated by RT-PCR in 33 cases, including all the immunohistochemically positive cases. Nine cases were SARS-CoV-2-positive by immunohistochemistry, in situ hybridization, and RT-PCR. These placentas showed lesions characterized by villous trophoblast necrosis with intervillous space collapse and variable amounts of mixed intervillous inflammatory infiltrate and perivillous fibrinoid deposition. Such lesions ranged from focal to massively widespread in five cases, resulting in intrauterine fetal death. Two of the stillborn fetuses showed some evidence of SARS-CoV-2 positivity. The remaining 189 placentas did not show similar lesions. The strong association between trophoblastic damage and placenta SARS-CoV-2 infection suggests that this lesion is a specific marker of SARS-CoV-2 infection in placenta. Diffuse trophoblastic damage, massively affecting chorionic villous tissue, can result in fetal death associated with COVID-19 disease.

Oral premalignant lesions of smokers and non-smokers show similar carcinogenic pathways and outcomes. A clinicopathological and molecular comparative analysis.

BACKGROUND: Oral premalignant lesions (OPML) are frequently extensive and multifocal leading high morbidity for patients. Although oral squamous carcinoma (OSCC) in non-smoker patients is increasing, little is known about OPML and the carcinogenesis process in these patients. The aims of the study were to insight and compare the clinicopathological and molecular characteristics of OPML of non-smoker and smoker patients from which one or multiple OSCC have developed. METHODS: Eighty-one patients showing extensive and/or multifocal OPML were included in the survey. HPV and EBV were investigated by PCR and in situ hybridization respectively. Cytogenetic studies were performed by microarray in sequential progressive 30 lesions; p53 expression was investigated by immunohistochemistry. RESULTS: The patients were 41 males and 40 females, ages ranging from 32 to 93 years (median 64); 43 (53%) were smokers. Non-smokers were more frequently female with a median age of 68, whereas smokers were men with a median age of 60 (P = 0.005). HPV and EBV were negative in all cases. The most consistent and earliest cytogenetic alterations in both non-smokers and smokers were loss of heterozygosity (LOH) and losses of locus harboring tumor suppressor genes. Progression to high-grade dysplasia and OSCC showed progressive addition of LOH, tumor suppressor losses, and oncogenic gains. CONCLUSION: Non-smoker patients are mostly elderly female and show oral carcinogenic pathways and outcomes similar to smoker patients.

Next-Generation Sequencing Gene Panels and "Solo" Clinical Exome Sequencing Applied in Structurally Abnormal Fetuses.

OBJECTIVE: The aim of the study was to assess the diagnostic yield of 2 different next-generation sequencing (NGS) approaches: gene panel and "solo" clinical exome sequencing (solo-CES), in fetuses with structural anomalies and normal chromosomal microarray analysis (CMA), in the absence of a known familial mutation. METHODOLOGY: Gene panels encompassing from 2 to 140 genes, were applied mainly in persistent nuchal fold/fetal hydrops and in large hyperechogenic kidneys. Solo-CES, which entails sequencing the fetus alone and only interpreting the Online Mendelian Inheritance in Man genes, was performed in multisystem or recurrent structural anomalies. RESULTS: During the study period (2015-2020), 153 NGS studies were performed in 148 structurally abnormal fetuses with a normal CMA. The overall diagnostic yield accounted for 35% (53/153) of samples and 36% (53/148) of the fetuses. Diagnostic yield with the gene panels was 31% (15/49), similar to 37% (38/104) in solo-CES. CONCLUSIONS: A monogenic disease was established as the underlying cause in 35% of selected fetal structural anomalies by gene panels and solo-CES.

Do the clinical criteria used to diagnose periodontitis affect the association with prematurity?

In recent years, several studies have examined the possible relationship between periodontal disease in pregnant women and preterm birth. One of the difficulties facing these studies is the heterogeneity of the clinical criteria used to define periodontitis. The aim of this cross-sectional study was to determine the degree of association between maternal periodontitis and preterm birth according to different consensus definitions of periodontal disease. In a study of 146 mothers (60 with preterm births and 86 with term deliveries) at the Sant Joan de Déu Maternal and Children's Hospital in Barcelona, a periodontal examination was carried out within 2 days of birth and the presence of periodontal disease was evaluated using the main clinical classifications published in the literature. The prevalence of periodontitis ranged from 25.4 to 52.1%, depending on the criteria used for its definition. Using the most restrictive criteria, pregnant women with periodontitis had a higher risk of preterm birth (OR: 7.49; p < 0.001) and premature rupture of membranes (OR: 2.49; p = 0.017). Premature infants born to mothers with periodontitis presented a tendency toward low weight, adjusted for gestational age (OR: 3.32; p = 0.065). Our findings suggest that the association between periodontitis and preterm birth is influenced by the definitions of periodontitis used.

Human papillomavirus in laryngeal and hypopharyngeal lymphoepithelial carcinoma.

The involvement of human papillomavirus (HPV) in laryngeal and hypopharyngeal lymphoepithelial carcinoma was investigated in a series of ten cases (seven laryngeal and three hypopharyngeal), retrieved from the files of three tertiary hospitals in the 2000-2017 period, through polymerase chain reaction with SPF10 primers and INNO-LiPA HPV Genotyping Extra II (Innogenetics). Epstein-Barr virus (EBV) was tested in all cases with in situ hybridization INFORM EBER Probe (Ventana Medical Systems). p16 and p53 expression were immunohistochemically analyzed. Calculated annual incidence was 0.013/100,000, and prevalence was 0.2% of laryngeal and hypopharyngeal carcinomas. All cases were EBV negative. HPV was detected in five cases, three of which also overexpressed p16. HPV16 was detected in four cases, and HPV58 in one case. Five cases were HPV negative, only one of these five overexpressed p16. No recurrence was observed in nine cases during follow-up. The 5-year disease-specific-survival rate was 100%. Mean overall survival was 87 months. Lymphoepithelial carcinoma of the larynx and hypopharynx are not related to EBV. Simultaneous HPV+/p16+ is consistent with HPV causation in a fraction of laryngeal and hypopharyngeal lymphoepithelial carcinomas.

Validity of a minimally invasive autopsy for cause of death determination in stillborn babies and neonates in Mozambique: An observational study.

BACKGROUND: Over 5 million stillbirths and neonatal deaths occur annually. Limited and imprecise information on the cause of these deaths hampers progress in achieving global health targets. Complete diagnostic autopsies (CDAs)-the gold standard for cause of death determination-are difficult to perform in most high-burden settings. Therefore, validation of simpler and more feasible methods is needed. METHODS AND FINDINGS: In this observational study, the validity of a minimally invasive autopsy (MIA) method in determining the cause of death was assessed in 18 stillbirths and 41 neonatal deaths by comparing the results of the MIA with those of the CDA. Concordance between the categories of diseases obtained by the 2 methods was assessed by the Kappa statistic, and the sensitivity, specificity, positive, and negative predictive values of the MIA diagnoses were calculated. A cause of death was identified in 16/18 (89%) and 15/18 (83%) stillborn babies in the CDA and the MIA, respectively. Fetal growth restriction accounted for 39%, infectious diseases for 22%, intrapartum hypoxia for 17%, and intrauterine hypoxia for 11% of stillborn babies. Overall, the MIA showed in this group a substantial concordance with the CDA (Kappa = 0.78, 95% CI [0.56-0.99]). A cause of death was identified in all (100%) and 35/41 (85%) neonatal deaths in the CDA and the MIA, respectively. In this group, the majority of deaths were due to infectious diseases (66%). The overall concordance of the MIA with the CDA in neonates was moderate (Kappa = 0.40, 95% CI [0.18-0.63]). A high percentage of accuracy was observed for the MIA in all the diagnostic categories in both stillbirths and neonates (>75%). The main limitation of this study is that some degree of subjective interpretation is inherent to cause-of-death attribution in both the MIA and the CDA; this is especially so in stillbirths and in relation to fetal growth restriction. CONCLUSIONS: The MIA could be a useful tool for cause-of-death determination in stillbirths and neonatal deaths. These findings may help to accelerate progress towards meeting global health targets by obtaining more accurate information on the causes of death in these age groups, which is essential in guiding the design of new interventions and increasing the effectiveness of those already implemented.

Endometrial Stromal Sarcoma Arising in Colorectal Endometriosis.

The malignant transformation of endometriosis is very uncommon. Whereas 75% of tumors arising from endometriosis arise in the ovary, location in extra-genital organs is rare and mesenchymal neoplasms are exceptional. A 47 year-old woman who underwent hysterectomy with bilateral salpingo-ooforectomy due to endometriosis 13 years before presented with abdominal pain. The magnetic resonance imaging (MRI) showed a 9.7×7.5 cm solid-cystic supravesical mass and a recto-vaginal tumor, as well as endometriotic nodules in the sigma, right parametrium and peritoneum that had significantly increased in size over a six months period. The patient underwent surgical resection of the masses. The histological study showed a low-grade endometrial stromal sarcoma (ESS) arising from endometriosis located at recotovaginal septum and affecting colonic wall and multiple peritoneal and pelvic implants. The patient received radiotherapy and aromatase inhibitors and is free of disease after a follow up of 2 years. Only 15 cases of ESS arising in endometriosis of the bowel have been reported. Tumor dissemination at diagnosis is unusual but does not imply a poor prognosis, as only one patient has died due to progression of the tumor. ESS should be included in the differential diagnosis of mesenchymal neoplasms in the intestine.

High-risk human papillomavirus is transcriptionally active in a subset of sinonasal squamous cell carcinomas.

It has been reported that high-risk human papillomavirus (HPV) is a causative agent of a subgroup of oropharyngeal carcinomas. In these tumors, the presence of the transcriptionally active HPV has been proved through the identification of HPV E6 or E7 messenger RNA (mRNA) transcripts. The aim of the study was to assess the HPV-active transcription in a series of sinonasal carcinomas, in correlation with the HPV DNA identification and the p16 immunohistochemistry. Seventy patients with squamous cell carcinomas of the sinonasal tract were included in the survey. The main clinicopathological characteristics were recorded. All tumors were investigated for HPV through the HPV DNA detection by PCR, using the SPF10 primers and by in situ hybridization, using the high-risk GenPoint probe (Dako, Glostrup, Denmark). HPV16 E7 mRNA transcripts detection was performed by RT-PCR in 27 cases. The immunostaining for p16 was performed in all cases. Fourteen carcinomas (20%) were positive for high-risk HPV by PCR: 13 HPV16 and one HPV35. In situ hybridization showed a dotted nuclear positivity in all these cases. HPV16 E7 mRNA was detected in seven tumors harboring HPV16; in the remaining HPV-positive cases, RNA did not reach the quality for analysis. Strong, diffuse positivity for p16 was observed only in the HPV-positive cases. The 14 HPV-positive squamous cell carcinomas were non-keratinizing or scarcely keratinizing tumors. No significant differences were found in terms of gender, age, or staging at diagnosis between HPV-positive and HPV-negative tumors. However, differences in disease-free survival and overall survival between both groups of patients were significant (P=0.004 and P=0.028, respectively). In conclusion, we have shown that HPV is the etiological agent of a subset of sinonasal carcinomas demonstrating the transcriptionally active HPV in these tumors. Immunostaining for p16 can be used as a surrogate marker to identify these tumors.

Cardiac dysfunction is associated with altered sarcomere ultrastructure in intrauterine growth restriction.

OBJECTIVE: The purpose of this study was to assess whether abnormal cardiac function in human fetuses with intrauterine growth restriction (IUGR) is associated with ultrastructural differences in the cardiomyocyte sarcomere. STUDY DESIGN: Nine severe early-onset IUGR fetuses and 9 normally grown fetuses (appropriate growth for gestational age) who died in the perinatal period were included prospectively. Cardiac function was assessed by echocardiography and levels of B-type natriuretic peptide and troponin-I. Heart sections were imaged by second harmonic generation microscopy, which allowed unstained visualization of cardiomyocyte's sarcomere length. RESULTS: Echocardiographic and biochemical markers showed signs of severe cardiac dysfunction in IUGR fetuses. Second harmonic generation microscopy demonstrated a significantly shorter sarcomere length in IUGR as compared with appropriate growth for gestational age fetuses. CONCLUSION: IUGR is associated with changes in the cardiomyocyte contractile machinery in the form of shorter sarcomere length, which could help to explain the cardiac dysfunction previously documented in IUGR.

Metastatic cutaneous squamous cell carcinoma accounts for nearly all squamous cell carcinomas of the parotid gland.

Primary squamous cell carcinoma of the parotid gland (pSCCP) has long been recognized as a separate entity and is included in the WHO classifications of salivary gland tumors. However, it is widely accepted among head and neck pathologists that pSCCP is exceptionally rare. Yet, there are many publications describing series of pSCCP and data from SEER and other cancer register databases indicate erroneously an increasing incidence of pSCCP. Importantly, pSCCP and metastatic (secondary) squamous cell carcinoma to the parotid gland (mSCCP) have nearly identical histological features, and the diagnosis of pSCCP should only be made after the exclusion of mSCCP. Moreover, all of the histological diagnostic criteria proposed to be in favor of pSCCP (such as, for example, dysplasia of ductal epithelium) can be encountered in unequivocal mSCCP, thereby representing secondary growth along preexistent ducts. Squamous cell differentiation has also been reported in rare genetically defined primary parotid carcinomas, either as unequivocal histological squamous features (e.g., NUT carcinoma, mucoepidermoid carcinoma), by immunohistochemistry (e.g., in NUT carcinoma, adamantinoma-like Ewing sarcoma, basal-type salivary duct carcinoma, mucoepidermoid carcinoma), or a combination of both. Another major issue in this context is that the International Classification of Diseases (ICD) coding system does not distinguish between primary or metastatic disease, resulting in a large number of patients with mSCCP being misclassified as pSCCP. Immunohistochemistry and new molecular biomarkers have significantly improved the accuracy of the diagnosis of many salivary gland neoplasms, but until recently there were no biomarkers that can accurately distinguish between mSCCP and pSCCP. However, recent genomic profiling studies have unequivocally demonstrated that almost all SCCP analyzed to date have an ultraviolet light (UV)-induced mutational signature typical of mSCCP of skin origin. Thus, mutational signature analysis can be a very useful tool in determining the cutaneous origin of these tumors. Additional molecular studies may shed new light on this old diagnostic and clinical problem. This review presents a critical view of head and neck experts on this topic.

Practical guidelines of the EOTTD for pathological and genetic diagnosis of hydatidiform moles.

Hydatidiform moles are rare and thus most pathologists and geneticists have little experience with their diagnosis. It is important to promptly and correctly identify hydatidiform moles given that they are premalignant disorders associated with a risk of persistent gestational trophoblastic disease and gestational trophoblastic neoplasia. Improvement in diagnosis can be achieved with uniformization of diagnostic criteria and establishment of algorithms. To this aim, the Pathology and Genetics Working Party of the European Organisation for Treatment of Trophoblastic Diseases has developed guidelines that describe the pathological criteria and ancillary techniques that can be used in the differential diagnosis of hydatidiform moles. These guidelines are based on the best available evidence in the literature, professional experience and consensus of the experts' group involved in its development.

Expression of Ep-CAM, but not of E48, associates with nodal involvement in advanced squamous cell carcinomas of the larynx.

AIMS: To evaluate epithelial cell adhesion molecule (Ep-CAM) and E48 expression, and their relationship with histological differentiation and nodal metastasis, in laryngeal squamous cell carcinomas (SCC). METHODS AND RESULTS: The expression of Ep-CAM and E48 was investigated using immunohistochemistry in a series of 66 SCC (stages 3 and 4) and their adjacent non-neoplastic epithelia. Ep-CAM expression increased with the progression from normal squamous epithelium to SCC. It was detected in 96% of carcinomas and high levels of Ep-CAM expression (50% or more positive cells) were associated with poorer differentiation (P = 0.003) and the presence of lymph node metastases (P = 0.001). E48 expression was characteristically strong and diffuse in non-neoplastic squamous epithelium, and decreased with progression to SCC. Poorly differentiated (grade 4) tumours had lower proportions of E48-positive cells than well- to moderately- differentiated cases (P < 0.001). CONCLUSIONS: Expression of both Ep-CAM and E48 correlated with cell differentiation, although in inverse fashion. In particular, the association between high levels of Ep-CAM expression and high frequency of nodal metastases suggests that Ep-CAM plays a role in the development of lymph node metastases in SCC of the larynx.

Correlation of placental lesions in patients with systemic lupus erythematosus, antiphospholipid syndrome and non-criteria obstetric antiphospholipid syndrome and adverse perinatal outcomes.

INTRODUCTION: We aimed to describe the pattern of placental injuries in women with systemic lupus erythematosus (SLE), antiphospholipid antibody syndrome (APS) and non-criteria obstetric APS (NC-OAPS), and to correlate the placental findings with the occurrence of adverse perinatal outcomes. METHODS: The perinatal outcomes and placental findings of pregnancies of women with SLE, APS, and NC-OAPS and gestational-age matched healthy controls were analyzed and classified according to the 2015 Redline - Classification of placental lesions. RESULTS: 91 women with SLE, APS, and NC-OAPS and 91 controls were included. Mean values of placental weight differed between groups, being significantly lower in NC-OAPS and APS groups compared to controls. Furthermore, 14.3% of placentas in the APS group were under the 3rd percentile, which was significantly higher in comparison with other groups. Regarding histopathological placental findings, maternal-side malperfusion was significantly increased in APS (46.4%) compared to NC-OAPS (14.3%) and SLE (9.5%). Fetal-side maldevelopment was significantly increased in NC-OAPS (19.1%) compared to controls (1.1%) and SLE (2.4%). A significantly increased prevalence of adverse perinatal outcomes (APOs) was observed in all studied groups compared to healthy controls (controls 3.3%, SLE 52.4%, NC-OAPS 57.1%, APS 64.3%). Overall, both maternal (OR 6.8, 95%CI 2.1-22) and fetal-side (OR 4.1, 95%CI 1.3-13.5) lesions were significantly associated with APO. Maternal malperfusion and fetal maldevelopment were the lesions most strongly associated with APOs. DISCUSSION: Pregnant women with SLE, APS, or NC-OAPS showed a different pattern of histopathological findings. Compared to controls, SLE, APS, and NC-OAPS conferred an increased risk of APOs that was strongly associated with placental maternal-side malperfusion and fetal-side maldevelopment.

Methylthioadenosine phosphorylase inactivation depends on gene deletion in laryngeal squamous cell carcinoma.

AIMS: Methylthioadenosine phosphorylase (MTAP) is an essential enzyme for the methionine and adenosine salvage pathway in normal cells, frequently inactivated in many different human cancers. MTAP status could be important for tumour cell sensitivity to adjuvant chemotherapy. To our knowledge, there have been no reports to date on MTAP status in laryngeal carcinoma. METHODS AND RESULTS: A series of 31 laryngeal squamous cell carcinomas was investigated for MTAP mRNA expression using reverse transcription and quantitative polymerase chain reaction (qPCR), as well as for MTAP gene deletion and/or promoter hypermethylation using qPCR and methylation-specific PCR, respectively. Low MTAP mRNA expression was found in 32% of cases, and was associated with MTAP gene deletion (in 70%; P<0.001) but not with MTAP promoter hypermethylation, indicating that, in this tumour, gene deletion is the main mechanism for MTAP inactivation. Neither low mRNA expression nor gene deletion was associated with any of the clinicopathological parameters investigated. CONCLUSION: Given the significance of MTAP status for cell sensitivity to different chemotherapeutic regimens, our results suggest that determination of MTAP inactivation should be taken into consideration in managing laryngeal squamous cell carcinomas.

Maternal IgM antibody status in confirmed fetal cytomegalovirus infection detected by sonographic signs.

OBJECTIVE: To evaluate the value of maternal IgM to cytomegalovirus (CMV) as a predictive factor of fetal infection in fetuses with sonographic markers. METHODS: Observational study (2006-2011) including a consecutive series of 19 fetuses with sonographic markers of fetal infection and confirmed infection by positive CMV-DNA in amniotic fluid or fetal blood. We evaluated the status of maternal CMV IgM at the time of sonographic suspicion. RESULTS: During this 6-year study period, CMV infection was diagnosed in 19 fetuses from 18 pregnancies, including 16 singletons, both twins of a monochorionic diamniotic pregnancy and one twin of a dichorionic pregnancy. Sonographic suspicion was established on the basis of one or more of the following: brain abnormalities (14), fetal hydrops (4), hyperechogenic bowel (4), pericardial effusion (1), cardiomegaly (1), oligoanhydramnios (4), and placentomegaly (2). Maternal IgG antibodies were positive in all cases but maternal IgM antibodies were negative in 56% of pregnancies. Five of the 10 pregnancies with negative maternal IgM were diagnosed in the second trimester and five in the third trimester. CONCLUSION: In around half of fetuses with confirmed CMV infection ascertained by sonographic markers, maternal IgM antibodies are negative and should therefore not be used as a diagnostic parameter.