Challenges of managing anomalous mitral arcade with severe mitral regurgitation and hydrops fetalis in infants.

Anomalous mitral arcade (MA) is a rare congenital anomaly. We report a case of MA in a newborn who presented with hydrops fetalis due to severe mitral regurgitation. After birth, he developed severe respiratory failure, congestive heart failure and airway obstruction because an enlarged left atrium from severe mitral regurgitation compressed the distal left main bronchus. There is limited experience in surgical management of this condition in Thailand, and the patient's mitral valve was too small for replacement. Therefore, he was treated with medication to control heart failure and supported with positive pressure ventilation to promote growth. We have followed the patient until the current time of writing this report at the age of 2 years, and his outcome is favourable regarding heart failure symptoms, airway obstruction, growth and development. This case describes a challenging experience in the non-surgical management of MA with severe regurgitation, which presented at birth.

Hydrops fetalis caused by a complex congenital heart defect with concurrent hypoplasia of pulmonary blood vessels and lungs visualized by micro-CT in a French Bulldog.

BACKGROUND: Hydrops fetalis (HF) is fluid accumulation in fetus body cavities and subcutaneous tissue. The condition has been described in various farm and companion animal species, including dogs. Most of cases result from a heart defect. Exact nature of this defect is rarely clarified. CASE PRESENTATION: A newborn, male French bulldog puppy with severe HF underwent a full anatomopathological examination to diagnose the primary cause of HF. Based on the anatomopathological examination, fetal ultrasound, and micro-computed tomography, transposition of the great arteries with hypoplasia of the ascending aorta, aortic arch interruption, ostium secundum atrial septal defect, severe tricuspid valve dysplasia, as well as hypoplasia of pulmonary vessels and lungs were diagnosed. CONCLUSIONS: This is the first report of HF caused by severe, complex congenital heart defects with concurrent pulmonary vessel and lung hypoplasia.

Fetal cardiac teratoma and pericardiocentesis: A case report.

Fetal pericardial teratomas are rare. They present with pericardial effusion and hydrops. The definitive management is postnatal resection of the tumor. The exact antenatal management is not known due to its rarity. We present a case of fetal pericardial teratoma with pericardial tamponade. Pericardiocentesis performed at 31 weeks significantly relieved the venous compression, leading to resolution of hydrops and prolonging the gestational age for the definitive management.

A singleton pregnancy with placental chorioangioma and hydrops fetalis complicated with mirror syndrome and ritodrine-induced side effects: a case report.

BACKGROUND: Ritodrine hydrochloride is a widely used beta-adrenergic agonist used to stop preterm labor in Taiwan. Many side effects causing maternal morbidity and mortality have been reported. We report a case complicated with ritodrine-induced side effects and mirror syndrome that was associated with placental chorioangioma. CASE PRESENTATION: A 36-year-old singleton pregnant woman at 25 6/7 weeks of gestation, with an undiagnosed placental chorioangioma, underwent tocolysis due to preterm uterine contractions. Her clinical condition deteriorated, attributed to mirror syndrome and adverse events induced by ritodrine. An emergency cesarean section was performed at 27 1/7 weeks of gestation, delivering an infant with generalized subcutaneous edema. A placental tumor measuring 8.5 cm was discovered during the operation, and pathology confirmed chorioangioma. Gradual improvement in her symptoms and laboratory data was observed during the postpartum period. Identifying mirror syndrome and ritodrine-induced side effects poses challenges. Therefore, this case is educational and warrants discussion. CONCLUSION: Our case demonstrates mirror syndrome induced by chorioangioma, which is rare, and ritodrine-induced side effects. The cessation of intravenous ritodrine and delivery are the best methods to treat maternal critical status due to fluid overload.

Perinatal Results and Long-Term Follow-Up of Fetal Cardiac Tumors: A 30-Year Historical Cohort Study. / Resultados Perinatais e Seguimento em Longo Prazo de Tumores Cardíacos Fetais: Estudo de Coorte Histórica de 30 Anos.

BACKGROUND: This was a 30-year retrospective cohort study that approximates closely to the natural history of cardiac tumors diagnosed in the fetus, since there was no case of pregnancy interruption. OBJECTIVE: To assess morbidity and mortality in the perinatal period and at long term in fetuses diagnosed with cardiac tumor. Our secondary objective was to assess the evaluating factors of perinatal and postnatal results. METHODS: This was a retrospective cohort study with 74 pregnant women with an echocardiographic diagnosis of fetal cardiac tumor at two referral centers between May 1991 and November 2021. A descriptive analysis was performed, and data were expressed as absolute (n) and relative (%) frequencies, median and interquartile range. Fisher's exact test was used to evaluate the association of echocardiographic characteristics and clinical manifestations with perinatal and postnatal results. Global survival was calculated using the Kaplan-Meier method and the curves were compared by the log-rank test. The time of follow-up, calculated in months, corresponded to the time elapsed from hospital discharge to current status (survived/ censoring or death). The level of significance was set at 5% (p<0.05). RESULTS: Rhabdomyoma is the most common type of cardiac tumor (85%), with a high morbidity (79.3%) and overall mortality of 17.4%. The presence of fetal hydrops was a predictor of death. CONCLUSION: The presence of fetal hydrops had an impact on mortality, and hence is an important factor in counselling and determining the prognosis. Most deaths occurred before hospital discharge.

FUNDAMENTO: Seguimento de coorte retrospectiva de 30 anos que se aproxima da história natural dos tumores cardíacos diagnosticados no feto uma vez que nenhum caso foi submetido à interrupção da gestação. OBJETIVO: Avaliar a morbidade e mortalidade perinatal e em longo prazo em fetos com diagnóstico de tumor cardíaco. Como objetivo secundário avaliar os fatores que influenciaram os resultados perinatais e pós-natais. MÉTODO: Estudo de coorte retrospectiva envolvendo 74 gestantes com diagnóstico ecocardiográfico fetal de tumor cardíaco acompanhadas em dois serviços de referência no período de maio de 1991 a novembro de 2021. Foi realizada análise descritiva dos dados por meio de frequências absolutas (n) e relativas (%), mediana e intervalos interquartis. Para avaliar a associação entre as características ecocardiográficas e as manifestações clínicas com os resultados perinatais e pós-natais, foi aplicado o teste exato de Fisher. O cálculo da sobrevida global foi realizado pelo método de Kaplan-Meier e a comparação de curvas pelo teste de log-rank. O tempo de seguimento, calculado em meses, foi definido a partir da data de alta do hospital à data do status atual (vivo/censura ou óbito). O nível de significância considerado foi de 5% (p<0,05). RESULTADOS: o rabdomioma é o tipo mais frequente (85%) de tumor cardíaco; apresenta alta morbidade (79,3%) e mortalidade geral de 17,4%; a presença de hidropisia fetal preditiva de óbito. CONCLUSÃO: A presença de hidropisia fetal teve impacto na mortalidade, sendo fator importante para aconselhamento e estabelecimento de prognóstico. A maioria dos óbitos ocorrem antes da alta hospitalar.

PIEZO Ion Channels in Cardiovascular Functions and Diseases.

The cardiovascular system provides blood supply throughout the body and as such is perpetually applying mechanical forces to cells and tissues. Thus, this system is primed with mechanosensory structures that respond and adapt to changes in mechanical stimuli. Since their discovery in 2010, PIEZO ion channels have dominated the field of mechanobiology. These have been proposed as the long-sought-after mechanosensitive excitatory channels involved in touch and proprioception in mammals. However, more and more pieces of evidence point to the importance of PIEZO channels in cardiovascular activities and disease development. PIEZO channel-related cardiac functions include transducing hemodynamic forces in endothelial and vascular cells, red blood cell homeostasis, platelet aggregation, and arterial blood pressure regulation, among others. PIEZO channels contribute to pathological conditions including cardiac hypertrophy and pulmonary hypertension and congenital syndromes such as generalized lymphatic dysplasia and xerocytosis. In this review, we highlight recent advances in understanding the role of PIEZO channels in cardiovascular functions and diseases. Achievements in this quickly expanding field should open a new road for efficient control of PIEZO-related diseases in cardiovascular functions.

Neonatal Lymphatic Flow Disorder.

OBJECTIVE: To examine and discuss patients diagnosed with acquired and congenital chylothorax in the neonatal period in the light of the literature. METHODS: The files of newborns followed-up in the neonatal intensive care unit (NICU) and diagnosed with congenital and acquired chylothorax were reviewed retrospectively. Patients with isolated chylothorax were classified as Group 1 and those with multiple lymphatic flow disorders were classified as Group 2. Antenatal and clinical features were recorded and compared between the groups. RESULTS: Thirteen infants were diagnosed with chylothorax; 92.3% (n = 12) of the patients were congenital. The rate of antenatal diagnosis was 61.5% (n = 8). Eight patients (61.5%) were diagnosed with hydrops fetalis. Among the cases in Group 1 and Group 2, receiving ocreotide and the incidence of sepsis (p = 0.05) were partially significant. Seven of the patients (66.6%) responded to medium chain triglycerides (MCT), and complete resolution was seen in 6 (85.7%) of the responders. Complete resolution of chylothorax fluid was observed in 7 (77.7%) of nine patients who responded to ocreotide treatment. CONCLUSIONS: In neonatal chylothorax, the postnatal period includes a multidisciplinary approach that requires drug therapy, dietary modifications, drainage of pleural fluid, and rarely, surgery.

Unique prenatal manifestations of biallelic NDUFAF5 variants: expansion of phenotype.

OBJECTIVE: Mitochondrial complex-I deficiency, nuclear type 16, is a rare autosomal recessive disorder caused by biallelic pathogenic variants in NDUFAF5 (C20orf7) (OMIM 618238). The aim of this study was to describe a severe early prenatal manifestation of this disorder, which was previously considered to occur only postnatally. METHODS: This was a multicenter retrospective case series including five fetuses from three non-related families, which shared common sonographic abnormalities, including brain cysts, corpus callosal malformations, non-immune hydrops fetalis and growth restriction. Genetic evaluation included chromosomal microarray analysis and exome sequencing. Two fetuses from the same family were also available for pathology examination, including electron microscopy. RESULTS: Chromosomal microarray analysis revealed no chromosomal abnormality in any of the tested cases. Trio exome sequencing demonstrated that three affected fetuses from three unrelated families were compound heterozygous or homozygous for likely pathogenic variants in NDUFAF5. No other causative variants were detected. The association between NDUFAF5 variants and fetal malformations was further confirmed by segregation analysis. Histological evaluation of fetal tissues and electron microscopy of the skeletal muscle, liver, proximal tubules and heart demonstrated changes that resembled postmortem findings in patients with mitochondrial depletion disorders as well as previously undescribed findings. CONCLUSIONS: Mitochondrial complex-I deficiency and specifically biallelic mutations in NDUFAF5 have a role in abnormal fetal development, presenting with severe congenital malformations. Mitochondrial complex-I disorders should be considered in the differential diagnosis of corpus callosal malformations and brain cysts, especially when associated with extracranial abnormalities, such as fetal growth restriction and non-immune hydrops fetalis. © 2023 International Society of Ultrasound in Obstetrics and Gynecology.

Outcome and etiology of fetal pleural effusion, fetal ascites and hydrops fetalis after fetal intervention: retrospective observational cohort from a single institution.

OBJECTIVES: Non-immune hydrops fetalis (NIHF) is the pathological accumulation of fluids in fetal compartments, without maternal isoimmunization. Fetal interventions (e.g. shunting, fetal paracentesis, fetal thoracocentesis, fetal pleurodesis) are used to alleviate fluid accumulations, but the outcome is uncertain because the underlying causes of NIHF vary. We aimed to explore the etiology and long-term outcome of NIHF after fetal intervention. METHODS: This was a retrospective review of fetuses with NIHF, defined by the presence of fetal ascites, pleural or pericardial effusion, skin edema or cystic hygroma, or a combination of these features, who underwent intervention at our institution during the period 2012-2021. Clinical surveillance, genetic analysis and viral infection screening were used to define the etiology. Chart reviews and telephone interviews were conducted to assess the long-term outcomes. RESULTS: In total, 55 fetuses were enrolled and 46 cases had final follow-up data after delivery. Etiology was identified in 33 cases, including four for which the underlying causes were not identified initially using small-gene-panel tests but which were later diagnosed with monogenic disorders by whole-exome sequencing (WES). Twenty-three cases with follow-up survived, having a follow-up period of 2-11 years at the time of writing, of which 17 were healthy. All 11 cases initially presenting as congenital chylothorax survived with favorable outcome. CONCLUSIONS: The etiologies of NIHF are heterogeneous, and the long-term (spanning 2-11 years) outcome of fetal intervention varies, according to the underlying etiology, with cases caused by congenital chylothorax having the best prognosis. Genome-wide tests, such as WES, may be helpful in determining the underlying condition in cases caused by a genetic disorder, and this may affect fetal therapy approaches in the future. © 2023 International Society of Ultrasound in Obstetrics and Gynecology.

SAM domain variants of EPHB4 associated with aberrant signaling are linked to lymphatic-related fetal hydrops and facial dysmorphology.

Variants in EPHB4 (Ephrin type B receptor 4), a transmembrane tyrosine kinase receptor, have been identified in individuals with various vascular anomalies including Capillary Malformation-Arteriovenous Malformation syndrome 2 and lymphatic-related (non-immune) fetal hydrops (LRHF). Here, we identify two novel variants in EPHB4 that disrupt the SAM domain in two unrelated individuals. Proband 1 presented within the LRHF phenotypic spectrum with hydrops, and proband 2 presented with large nuchal translucency prenatally that spontaneously resolved in addition to dysmorphic features on exam postnatally. These are the first disease associated variants identified that do not disrupt EPHB4 protein expression or tyrosine-kinase activity. We identify that EPHB4 SAM domain disruptions can lead to aberrant downstream signaling, with a loss of the SAM domain resulting in elevated MAPK signaling in proband 1, and a missense variant within the SAM domain resulting in increased cell proliferation in proband 2. This data highlights that a functional SAM domain is required for proper EPHB4 function and vascular development.

Prognostic accuracy of factors associated with poor outcome in prenatally diagnosed sacrococcygeal teratoma: A systematic review and meta-analysis.

Several factors associated with poor outcome in patients with prenatally diagnosed sacrococcygeal teratoma (SCT) have been found. However, the prognostic accuracy of these factors has not been well established. Therefore, we aimed to systematically review the prognostic accuracy of factors associated with poor outcome in these patients. We queried Search Premier, COCHRANE Library, EMCARE, EMBASE, PubMed, ScienceDirect, and Web of Science databases to identify studies regarding patients with prenatally diagnosed SCT. Poor outcome was defined as termination of pregnancy (TOP), intrauterine fetal death (IUFD), or perinatal death. We estimated the odds ratio of factors associated with poor outcome. Eleven studies (447 patients) were included. Overall mortality, including TOP, was 34.9%. Factors associated with poor outcome in fetuses with prenatally diagnosed SCT were cardiomegaly, hypervascular tumor, solid tumor morphology, fetal hydrops, and placentomegaly. A tumor volume to fetal weight ratio (TFR) of >0.12 before a gestational age of 24 weeks is predictive of poor outcome. The prognostic accuracy of factors associated with poor outcome in fetuses prenatally diagnosed with SCT seems promising. Factors associated with cardiac failure such as cardiomegaly, hypervascular tumor, solid tumor morphology, fetal hydrops, placentomegaly, and TFR >0.12 were found to be predictive of poor outcome.

Prenatal diagnosis of mucopolysaccharidosis type VII facilitating treatment in neonatal period.

Duo exome testing was performed on a fetus conceived via in vitro fertilization with an egg donor. The fetus presented with non-immune hydrops fetalis (NIHF) at 20 + 0 weeks gestation. Two variants were detected in the GUSB gene. Biallelic pathogenic variants cause mucopolysaccharidosis type VII (MPS-VII), which can present with NIHF prenatally. At the time of analysis and initial report, one variant was classified as likely pathogenic and the other as of uncertain clinical significance. Biochemical testing of the amniotic fluid supernatant showed elevated glycosaminoglycans and low ß-glucuronidase activity consistent with the diagnosis of MPS-VII. This evidence allowed the upgrade of the pathogenicity for both variants, confirming the diagnosis of MPS-VII. The infant was born at 36 + 5 weeks and enzyme replacement therapy (ERT) using vestronidase was initiated at 20 days with planning for hematopoietic stem cell transplant ongoing. The ERT therapy has been well tolerated, with decreasing quantitative urine glycosaminoglycans. Long-term follow up is required to determine whether treatment has been successful. This case demonstrates the utility of alternative testing methods to clarify the pathogenicity of variants and the clinical utility of obtaining a diagnosis antenatally in facilitating treatment in the neonatal period, and specifically highlights MPS-VII as a treatable cause of NIHF.

Late third trimester diagnosis of congenital giant hemangioma complicated by the Kasabach-Merritt phenomen: a case report and literature review.

Objective. To describe the case of a large cervical mass diagnosed in the late third trimester with development of Kasabach-Merritt phenomenon (KMP) in the immediate postnatal period, along with a literature review.Methods. Description of case-report and literature search through Medline/Pubmed, performed from inception to December 2022 for articles relating to the pre and postnatal diagnosis of KMP.Results. A 36-year-old multiparous woman was admitted to hospital for contractions at 40 weeks of gestation, in an otherwise uneventful pregnancy. Admission's ultrasound showed the presence of a voluminous mass of 14x15 cm of the posterior side of the neck, highly vascularized, and no signs of hemodynamic imbalance. Postnatally, blood tests showed the presence of severe anemia and thrombocytopenia requiring several transfusions of blood, plasma, platelets and clotting factors. Due to the association of congenital hemangioma and thrombocytopenia a diagnosis of KMP was made. After attempts of conservative treatment, surgical removal was needed to stop the hematological cascade with regression of symptoms. The review of the literature identified 14 articles including 9 cases of prenatally suspected KMP and 6 diagnosed in the immediate postnatal period and without signs of fetal hydrops. Adverse perinatal outcome, in terms of postnatal death/termination of pregnancy, was observed in 67% of cases (6/9) in the prenatally suspected group and 33% of cases in those with a postnatal diagnosis of KMP. Fetal hydrops was present in 83% of cases with adverse perinatal outcome.Conclusions. The Kasabach-Merrit syndrome is a rare condition, which can have a dangerous evolution when it develops in utero or in the immediate postnatal period carrying a risk of perinatal mortality of approximately 50%. Even if the fetus shows no signs of anemia or heart failure, the risk of developing it in the immediate postnatal period is high and should be mentioned to the couple.

Prenatally Diagnosed Large Lung Lesions: Timing of Resection and Perinatal Outcomes.

INTRODUCTION: Fetuses with large lung lesions including congenital cystic adenomatoid malformations (CCAMs) are at risk for cardiopulmonary compromise. Prenatal maternal betamethasone and cyst drainage for micro- and macrocystic lesions respectively have improved outcomes yet some lesions remain large and require resection before birth (open fetal surgery, OFS), at delivery via an Ex Utero Intrapartum Treatment (EXIT), or immediately post cesarean section (section-to-resection, STR). We sought to compare prenatal characteristics and outcomes in fetuses undergoing OFS, EXIT, or STR to inform decision-making and prenatal counseling. METHODS: A single institution retrospective review was conducted evaluating patients undergoing OFS, EXIT, or STR for prenatally diagnosed lung lesions from 2000 to 2021. Specimens were reviewed by an anatomic pathologist. Lesions were divided into "CCAMs" (the largest pathology group) and "all lung lesions" since pathologic diagnosis is not possible during prenatal evaluation when care decisions are made. Prenatal variables included initial, greatest, and final CCAM volume-ratio (CVR), betamethasone use/frequency, cyst drainage, and the presence of hydrops. Outcomes included survival, ECMO utilization, NICU length of stay (LOS), postnatal nitric oxide use, and ventilator days. RESULTS: Sixty-nine percent (59 of 85 patients) of lung lesions undergoing resection were CCAMs. Among patients with pathologic diagnosis of CCAM, the initial, largest, and final CVRs were greatest in OFS followed by EXIT and STR patients. Similarly, the incidence of hydrops was significantly greater and the rate of hydrops resolution was lower in the OFS group. Although the rate of cyst drainage did not differ between groups, maternal betamethasone use varied significantly (OFS 60.0%, EXIT 100.0%, STR 74.3%; p = 0.0378). Notably, all OFS took place prior to 2014. There was no difference in survival, ventilator days, nitric oxide, NICU LOS, or ECMO between groups. In multiple variable logistic modeling, determinants of survival to NICU discharge among patients undergoing resection with a pathologic diagnosis of CCAM included initial CVR <3.5 and need for <3 maternal betamethasone doses. CONCLUSION: For CCAMs that remain large despite maternal betamethasone or cyst drainage, surgical resection via OFS, EXIT, or STR are viable options with favorable and comparable survival between groups. In the modern era there has been a shift from OFS and EXIT procedures to STR for fetuses with persistently large lung lesions. This shift has been fueled by the increased use of maternal betamethasone and introduction of a Special Delivery Unit during the study period and the appreciation of similar fetal and neonatal outcomes for STR vs. EXIT and OFS with reduced maternal morbidity associated with a STR. Accordingly, efforts to optimize multidisciplinary perinatal care for fetuses with large lung lesions are important to inform patient selection criteria and promote STR as the preferred surgical approach in the modern era. LEVEL OF EVIDENCE: Level IV.

Multidisciplinary management of a large microcystic congenital pulmonary airway malformation: case report and literature review.

INTRODUCTION: Congenital pulmonary airway malformations (CPAMs) are rare sporadic lesions frequently associated with poor fetal prognosis. Type 3 CPAMs are characterized by small hyperechogenic cysts (<5 mm). Hydrops often develops secondarily, and the fetal survival rate is approximately 5% in this setting. CASE PRESENTATION: We present a case of a large type 3 CPAM complicated by fetal hydrops. The lesion was detected at 19 gestational weeks (GW) and confirmed by fetal MRI at 29 GW. At 22 GW, a course of maternal steroids was given as a possible treatment of type 3 CPAM. Peritoneal-amniotic shunt was placed twice to reduce fetal ascites, with unsatisfactory results. Similarly, polyhydramnios was relieved by two amnioreductions, but redeveloped soon after. A baby girl was delivered spontaneously at 33 GW and received a two-stage partial lobectomy in the first three months of life. Desaturations necessitated challenging invasive oscillatory ventilation between stages. Her outcome is unexpectedly positive and she may expect a good quality of life. She now approaches one year of age, with near-to-normal growth and developmental milestones. DISCUSSION: Type 3 CPAMs complicated by fetal hydrops are associated with high perinatal mortality. While open fetal surgery remains a viable option in select specialist centers, antenatal interventions are typically ineffective. The survival of this infant can be attributed to prenatal management and early postnatal surgical intervention. The lack of guidelines for ventilation in this setting was a significant challenge for neonatal intensivists. Multidisciplinary vigilance and collaboration with frequent specialist follow ups were the key to success for both mother and child.

Isoinmunización Rh en bajas respondedoras: Reporte de caso / Rh Isoimmunization in Low Responders: Case Report / Isoimunização Rh em pacientes com baixa resposta: relato de caso

Introducción. La isoinmunización Rh consiste en la producción de anticuerpos maternos en una gestante Rh negativa contra los antígenos de los eritrocitos Rh positivos fetales ocasionados por una hemorragia fetomaterna. En población gestante, el 15% son Rh negativo y la severidad de la afectación fetal está relacionada con una serie de procesos inmunológicos y la historia obstétrica. Si una gestante Rh negativa con riesgo de isoinmunización no recibe profilaxis con inmunoglobulina Anti-D se inmuniza el 16% en la primera gestación, el 30% en la segunda y el 50% después de la tercera. Con este reporte de caso queremos describir el subgrupo de pacientes gestantes con isoinmunización Rh bajas respondedoras. Presentación del caso. G9P5C1A2Gem1V7 de 43 años, remitida en semana 30 de gestación por isoinmunización Rh, no recibió inmunoglobulina Anti-D durante este embarazo, ni en los anteriores ni en el posparto, reporte de Coombs indirecto de 1/4 que se eleva a 1/16, seguimiento ecográfico normal. En semana 35.3 presenta anemia fetal leve y por tratarse de un embarazo alrededor del término se finaliza por cesárea. Recién nacido con adecuado peso para la edad gestacional, quien fue dado de alta a las 72 horas con evolución satisfactoria. Discusión. Las gestantes con isoinmunización Rh bajas respondedoras se sensibilizan con altos volúmenes sanguíneos sin repercusión hemodinámica in utero, produciendo una enfermedad hemolítica fetal leve. Esta respuesta inmune es poco frecuente y está asociada a factores protectores; sin embargo, son necesarios más estudios que sustenten esta condición. Conclusiones. El control prenatal y el Coombs indirecto cuantitativo seriado son las principales herramientas para la prevención de la isoinmunización. El conocimiento de la respuesta inmunológica permite identificar el subgrupo de las bajas respondedoras que tienen una evolución clínica más leve y menor morbilidad neonatal. Palabras clave: Embarazo; Isoinmunización Rh; Eritroblastosis Fetal; Globulina Inmune RHO(D); Hidropesía Fetal.

Introduction. Rh isoimmunization consists of a Rh-negative pregnant woman producing maternal antibodies against the antigens of fetal Rh-positive erythrocytes due to fetomaternal hemorrhage. 15% of the pregnant population is Rh negative, and the severity of fetal effects is related to a series of immunological processes and the obstetric history. If a Rh-negative pregnant woman at risk of isoimmunization does not receive a prophylaxis of Anti-D immunolobulin, 16% are immunized in the first pregnancy, 30% in the second and 50% after the third. In this case report we will describe the subgroup of low responder pregnant patients with Rh isoimmunization. Case Presentation. G9P5C1A2Gem1V7, 43 years old, referred on the 30th week of pregnancy due to Rh isoimmunization. She did not receive Anti-D immunolobulin during this pregnancy, nor in her previous pregnancies, nor during postpartum. Indirect Coombs report of 1/4, which increases to 1/16. Ultrasound monitoring is normal. At week 35.3 she presented mild fetal anemia, and because the pregnancy was near its term, it was ended by cesarean section. Newborn with adequate weight considering the gestational age, who was then discharged after 72 hours with satisfactory evolution. Discussion. Low responder pregnant women with Rh isoimmunization are sensitized with high blood volumes but without hemodynamic repercussions in utero, producing a mild fetal hemolytic disease. This immune response is infrequent and is associated with protective factors; however, further studies are required to support this condition. Conclusions. Prenatal control and serialized quantitative indirect Coombs testing are the main tools for the prevention of isoimmunization. Knowledge of the immunological response enables identifying the subgroup of low responders who present a milder clinical evolution and lower newborn morbidity. Keywords: Pregnancy; Rh Isoimmunization; Erythroblastosis, Fetal; RHO(D) Immune Globulin; Hydrops Fetalis.

Introdução. A isoimunização Rh consiste na produção de anticorpos maternos em uma gestante Rh negativa contra os antígenos dos eritrócitos fetais Rh positivos causados por hemorragia fetomaterna. Na população gestante, 15% são Rh negativos e a gravidade do envolvimento fetal está relacionada a uma série de processos imunológicos e ao histórico obstétrico. Se uma gestante Rh negativa com risco de isoimunização não receber profilaxia com imunoglobulina Anti-D, imuniza-se 16% na primeira gestação, 30% na segunda e 50% após a terceira. Com este relato de caso, queremos descrever o subgrupo de pacientes gestantes com isoimunização Rh de baixa resposta. Apresentação do caso. G9P5C1A2Gem1V7, 43 anos, encaminhada na 30ª semana de gestação para isoimunização Rh, não recebeu imunoglobulina Anti-D nesta gestação, nem nas anteriores nem no puerpério, laudo de Coombs indireto de 1/4 que sobe para 1/16, acompanhamento ultrassonográfico normal. Na semana 35,3, apresentou anemia fetal leve e por se tratar de uma gestação próxima ao termo, foi interrompida por cesariana. Recém-nascido com peso adequado para a idade gestacional, que recebeu alta às 72 horas com evolução satisfatória. Discussão. Gestantes com isoimunização Rh de baixa resposta são sensibilizadas com elevados volumes sanguíneos sem repercussões hemodinâmicas in utero, produzindo doença hemolítica fetal leve. Essa resposta imune é rara e está associada a fatores protetores; no entanto, mais estudos são necessários para fundamentar esta condição. Conclusões. O controle pré-natal e o Coombs indireto quantitativo seriado são as principais ferramentas para a prevenção da isoimunização. O conhecimento da resposta imunológica permite identificar o subgrupo de pacientes com baixa resposta que apresentam evolução clínica mais branda e menor morbidade neonatal. Palavras-chave: Gravidez; Isoimunização Rh; Eritroblastose Fetal; Inmunoglobulina RHO (D), Hidropisia Fetal.

First-trimester septated cystic hygroma, marked non-immune fetal hydrops, 45,X and coarctation of the aorta with neonatal survival.

Marked first-trimester nonimmue hydrops fetalis and 45,X with neonatal survival.

Perinatal-lethal nonimmune fetal hydrops attributed to MECOM-associated bone marrow failure.

Pathogenic variants in MECOM, a gene critical to the self-renewal and proliferation of hematopoietic stem cells, are known to cause a rare bone marrow failure syndrome associated with amegakaryocytic thrombocytopenia and bilateral radioulnar synostosis known as RUSAT2. However, the spectrum of disease seen with causal variants in MECOM is broad, ranging from mildly affected adults to fetal loss. We report two cases of infants born preterm who presented at birth with symptoms of bone marrow failure including severe anemia, hydrops, and petechial hemorrhages; radioulnar synostosis was not observed in either patient, and, unfortunately, neither infant survived. In both cases, genomic sequencing revealed de novo variants in MECOM considered to be responsible for their severe presentations. These cases add to the growing body of literature that describe MECOM-associated disease, particularly MECOM as a cause of fetal hydrops due to bone marrow failure in utero. Furthermore, they support the use of a broad sequencing approach for perinatal diagnosis, as MECOM is absent from available targeted gene panels for hydrops, and highlight the importance of postmortem genomic investigation.

Fetal hydrops caused by a novel pathogenic MECOM variant.

We report a fetus with hydrops, congenital heart disease and bilateral radioulnar synostosis caused by a novel pathogenic MECOM variant. The female fetus was referred for post-mortem examination after fetal hydrops and intrauterine death was diagnosed at 20 weeks gestation. Post-mortem examination confirmed fetal hydrops, pallor, truncus arteriosus and bilateral radioulnar synostosis. Trio whole genome sequencing analysis detected a novel de novo heterozygous pathogenic loss-of-function variant in MECOM (NM_004991), associated with a diagnosis of Radioulnar Synostosis with Amegakaryocytic Thrombocytopenia 2 (RUSAT-2). RUSAT-2 is a variable condition associated postnatally with bone marrow failure, radioulnar synostosis and congenital anomalies. RUSAT-2 is not currently associated with a prenatal phenotype or fetal demise, and was not present on diagnostic NHS prenatal gene panels at time of diagnosis. This case highlights the diagnostic value of detailed phenotyping with post-mortem examination, and of using a broad sequencing approach.