Society for maternal-fetal medicine (SMFM) clinical guideline #7: nonimmune hydrops fetalis

Evaluation of Non-Immune Fetal Hydrops in Resource Poor Country: Challenges Faced in Ascertaining the Etiology

OBJECTIVE

Analyze the proportion of cases of non-immune hydrops fetalis (NIHF), where etiology could be ascertained using limited tests and determine outcome.

METHOD

A retrospective observational study of prenatally diagnosed NIHF at a tertiary referral center in India over 10 years from 2014 to 2023 using the data retrieved from case files, ultrasound and investigation reports.

RESULTS

Included 184 NIHF events in 166 patients with an estimated prevalence of 0.11% (184/160,156 deliveries). 42.5% of women were primigravida and 30 cases were in 12 patients presenting with recurrent hydrops. Etiology could be ascertained in 76/154 (49.35%) total new cases of hydrops presenting for the first time and in 9/12 (75%) total patients with recurrent NIHF. The most common causes among first time NIHF were structural anomalies and aneuploidies, while inborn errors of metabolism (IEM) were the most common in recurrent cases. The diagnostic yield of ultrasound alone was 30.7% (51/166 patients), which improved with addition of tests to 45.78% (76/166) with cytogenetic and 53.6% (89/166) with sequencing studies. The overall survival beyond 28 days of postnatal life was 9.2% (17/184 events), with the rest ending in MTP/spontaneous abortion 47.8% (88/184), stillbirth 24.5% (45/184), early neonatal death 17.4% (32/184) and late neonatal death 1.1% (2/184). Treatable causes included fetal arrhythmias, some structural anomalies and certain IEMs amenable to early postnatal dietary intervention.

CONCLUSION

Although overall survival in NIHF is poor, the aim of diagnostic workup should be to find a treatable cause. Even with limited resources, etiology can still be deduced in more than half of the cases. Management decisions can often be made based on history and ultrasonography while restricting the expensive genetic tests to unexplained or recurrent cases.

Genetic diseases underlying a spectrum of fetal effusions

OBJECTIVES

Nonimmune hydrops fetalis is well understood to be heterogenous and the common endpoint of many genetic diseases. However, less is known about the prevalence and presenting features of genetic diseases that underlie other types of fetal effusions such as single effusions, leaving uncertainty in clinical practice about optimal approaches to testing and counseling for these pregnancies. We aimed to determine the diagnostic yield of exome sequencing by type of fetal effusion and presence of concurrent structural abnormalities and to identify the unique presenting features of underlying genetic diseases.

STUDY DESIGN

We conducted a prospective cohort study of pregnancies with nonimmune hydrops fetalis and other fetal effusions, with participants enrolled from across the United States. Inclusion criteria were nondiagnostic results of chromosomal microarray and/or karyotype and the presence of at least 1 fetal effusion, including nuchal translucency ≥3.5 mm, cystic hygroma, pleural effusion, pericardial effusion, ascites, and/or skin edema. Exome sequencing was performed by our institution's Clinical Laboratory Improvement Amendments-approved laboratory and results were returned to participants and their providers. Detailed fetal phenotypic data were ascertained and used to inform genetic variant interpretation, including fetal imaging findings (ultrasound, magnetic resonance imaging, and echocardiogram), pathology reports, and laboratory reports. Pregnancies with a variant or variants classified as pathogenic or likely pathogenic were considered diagnostic or positive. The primary outcome was the diagnostic yield of exome sequencing by the type of fetal effusion, with and without concurrent structural abnormalities. Secondary outcomes were the types of fetal effusions observed by category of genetic disease.

RESULTS

In all, 118 pregnancies with nonimmune hydrops fetalis and other effusions underwent exome sequencing and 23% (27/118) had positive (diagnostic) findings. Pregnancies with nonimmune hydrops fetalis with and without concurrent structural abnormalities had diagnostic yields of 21% (9/42) and 40% (6/15), respectively (P=.15). Single effusions such as pleural effusion with and without concurrent structural abnormalities had diagnostic yields of 23% (6/26) and 17% (1/6), respectively (P=.61). The diagnostic yield for increased nuchal translucency or cystic hygroma was significantly greater for pregnancies with concurrent structural abnormalities (42%, 5/12) compared to those without (0%, 0/17, P<.01). We further observed numerous patterns in terms of how genetic diseases present in utero, such as RASopathies and musculoskeletal disorders demonstrating all types of effusions, while other disorders marked by neurodevelopmental delays after birth demonstrated all types of effusions except for nonimmune hydrops fetalis.

CONCLUSION

The diagnostic yield of exome sequencing was high across all types of effusions including single effusions with and without concurrent structural abnormalities, with the exception of isolated increased nuchal translucency or cystic hygroma. Furthermore, we observed numerous patterns in terms of how genetic diseases present in utero with fetal effusions. These findings contribute important information for counseling and clinical management, highlight the utility of exome sequencing for fetal effusions beyond nonimmune hydrops fetalis, and inform accurate results of phenotype-driven tests such as exome sequencing.

Utility of serial fetal echocardiograms in detecting in-utero changes for single-ventricle lesions: an 11-year experience

OBJECTIVE

Current guidelines in fetal echocardiography recommend serial evaluation every 4 weeks for single-ventricle lesions. However, there are limited data on the type and frequency of in-utero cardiac changes seen on fetal echocardiograms (FEs) based on the type of single-ventricle lesion. We aimed to evaluate the utility of serial FEs in detecting cardiac changes during gestation and how these changes impact postnatal management.

METHODS

We performed a retrospective review of all FEs for fetuses diagnosed with a single-ventricle lesion at the Children's Healthcare of Atlanta, between January 2012 and January 2023. All patients included in the study had two or more FEs and were evaluated for in-utero cardiac changes based on eight cardiac categories: atrioventricular (AV) valve regurgitation; systemic ventricular dysfunction; ductus arteriosus flow; atrial-level restriction; umbilical artery Doppler pattern; umbilical vein Doppler pattern; evidence of hydrops; and evidence of arrhythmias. All in-utero cardiac changes were classified into three categories: improving, worsening or critical. Any changes noted on serial FEs that altered the fetal cardiac diagnosis were also recorded. Fisher's exact test was used to determine whether the proportion of fetuses with in-utero cardiac changes differed significantly between different segmental findings and single-ventricle lesion subtype.

RESULTS

A total of 721 FEs were performed for 248 patients over the 11-year study period. The majority of fetuses had hypoplastic left heart syndrome (HLHS) (63.7%) and most changes were seen in the third trimester (median gestational age, 29.3 (range, 17.4-38.4) weeks). In-utero cardiac changes observed on serial FEs were reported in 38 (15.3%) fetuses, with a total of 42 changes noted throughout the study period. However, only eight (3.2%) fetuses had a critical change that impacted perinatal management. All eight fetuses had HLHS, of which the majority developed hydrops (4/8) or atrial-level restriction (3/8). In addition, there were 34 non-critical changes seen in 30 (12.1%) fetuses, largely in the form of intermittent premature atrial contractions, AV valve regurgitation or ventricular dysfunction. There were 12 (2.5%) follow-up FEs that resulted in a change to the fetal cardiac diagnosis, confirmed by postnatal echocardiography.

CONCLUSION

In fetuses with single-ventricle lesions, there was a low rate of in-utero cardiac changes that led to alterations in perinatal management. However, fetuses with HLHS were most likely to develop critical changes affecting delivery-room management, often in the form of atrial-level restriction and/or evolving hydrops. It is important to consider these factors when considering the timing of visits for families who face a prenatal diagnosis of a single-ventricle lesion. © 2025 International Society of Ultrasound in Obstetrics and Gynecology.

Biallelic variants in the conserved ribosomal protein chaperone gene PDCD2 are associated with hydrops fetalis and early pregnancy loss

Pregnancy loss is a major problem in clinical medicine with devastating consequences for families. Next generation sequencing has improved our ability to identify underlying molecular causes, though over half of all cases lack a clear etiology. Here, we began with clinical evaluation combined with exome sequencing across independent families to identify bi-allelic candidate genetic variants in the Programmed Cell Death 2 (PDCD2) gene in multiple fetuses with nonimmune hydrops fetalis (NIHF). PDCD2 is an evolutionarily conserved protein with no prior association with monogenic disorders. PDCD2 is known to act as a molecular chaperone for the ribosomal protein uS5, and this complex formation is important for incorporation of uS5 into the 40S subunit, a crucial step in ribosome biogenesis. Primary fibroblasts from an affected fetus and cell lines expressing PDCD2 patient variants demonstrated reduced levels of PDCD2, reduced PDCD2 binding to uS5, and altered ribosomal RNA processing. Xenopus tadpoles with Pdcd2 knockdown demonstrated developmental defects and edema, reminiscent of the NIHF seen in affected fetuses, and showed altered ribosomal RNA processing. Through genetic, biochemical, and in vivo approaches, we provide evidence that bi-allelic PDCD2 variants cause an autosomal recessive ribosomal biogenesis disorder resulting in pregnancy loss.

The Utility of a Critical Antibody Titer in Anti-K Alloimmunized Pregnancies: A Systematic Review and Meta-Analysis of Diagnostic Test Accuracy

Anti-Kell (anti-K) alloimmunization is a known cause of severe hemolytic disease of the fetus and newborn (HDFN), yet the utility of a critical maternal antibody titer in guiding clinical management remains debated. We conducted a systematic review and meta-analysis to evaluate the diagnostic accuracy of a maternal anti-K titer threshold of ≥8 for predicting the need for intrauterine intervention due to severe anti-K-mediated HDFN. In parallel, we characterized all reported cases of severe HDFN occurring in the setting of low maternal anti-K titers (<8). Studies were excluded if they lacked reported titers, did not include K-positive or K-unknown fetuses, failed to report fetal outcomes, or included interventions that could lower maternal alloantibody levels. Studies that assessed all alloimmunized patients meeting inclusion criteria were incorporated into a diagnostic test accuracy (DTA) meta-analysis; all eligible studies were included in a qualitative synthesis. Fifty-four studies, comprising 582 fetuses, met inclusion criteria. Of these, 6 studies (350 fetuses) were included in the DTA analysis, which demonstrated a pooled sensitivity of 97.0% (95% CI, 88.7%-99.2%) and specificity of 33.1% (95% CI, 27.9%-38.8%) for an anti-K titer ≥8. Among fetuses affected by severe HDFN, 98.6% (204/207) were associated with maternal anti-K titers ≥8. These findings suggest that severe disease is uncommon in the setting of low anti-K titers and support the use of a critical titer threshold to inform antenatal surveillance. Reevaluation of current clinical guidelines may be warranted in light of these data.

Differential Diagnosis of Hydrops Fetalis: An Imaging Guide

Hydrops fetalis is a critical diagnosis given the poor prognosis and vast differential of potential causes. After a detailed anatomic survey, the first step in differentiating among the various causes is measurement of the middle cerebral artery peak systolic velocity to evaluate for anemia. Anemia is the key decision point in the diagnostic algorithm that categorizes hydrops. This approach is more practical than an immune versus nonimmune classification because it capitalizes on clues available at the time of sonographic diagnosis and expedites care toward possible therapies, such as intrauterine transfusion. The causes of hydrops that share the underlying physiology of fetal anemia include alloimmunization, which accounts for 10% of cases, congenital infections, hemoglobinopathies, and fetomaternal hemorrhage. After ruling out anemia, the differential diagnosis expands to cardiovascular disorders (20%-28% of cases), genetic abnormalities (10%-30% of cases), fetal masses (eg, congenital lung masses, sacrococcygeal teratomas), and monochorionic twin complications. Even after a thorough evaluation, 15% of hydrops cases remain of unknown cause. There are treatments available for select disorders that have the potential to reverse the signs of hydrops. Several imaging pitfalls should be avoided when establishing the diagnosis of hydrops, such as mistaking abdominal wall muscles, physiologic pericardial fluid, or thick subcutaneous tissue as pathologic fluid accumulation. A practical and comprehensive approach to the diagnostic evaluation for hydrops fetalis avoids delays in diagnosis and expedites potential life-saving treatment of this disorder. ©RSNA, 2025 Supplemental material is available for this article.

Advancing fetal diagnosis and prognostication using comprehensive prenatal phenotyping and genetic testing

Prenatal diagnoses of congenital malformations have increased significantly in recent years with use of high-resolution prenatal imaging. Despite more precise radiological diagnoses, discussions with expectant parents remain challenging because congenital malformations are associated with a wide spectrum of outcomes. Comprehensive prenatal genetic testing has become an essential tool that improves the accuracy of prognostication. Testing strategies include chromosomal microarray, exome sequencing, and genome sequencing. The diagnostic yield varies depending on the specific malformations, severity of the abnormalities, and multi-organ involvement. The utility of prenatal genetic diagnosis includes increased diagnostic clarity for clinicians and families, informed pregnancy decision-making, neonatal care planning, and reproductive planning. Turnaround time for results of comprehensive genetic testing remains a barrier, especially for parents that are decision-making, although this has improved over time. Uncertainty inherent to many genetic testing results is a challenge. Appropriate genetic counseling is essential for parents to understand the diagnosis and prognosis and to make informed decisions. Recent research has investigated the yield of exome or genome sequencing in structurally normal fetuses, both with non-invasive screening methods and invasive diagnostic testing; the prenatal diagnostic community must evaluate and analyze the significant ethical considerations associated with this practice prior to generalizing its use. IMPACT: Reviews available genetic testing options during the prenatal period in detail. Discusses the impact of prenatal genetic testing on care using case-based examples. Consolidates the current literature on the yield of genetic testing for prenatal diagnosis of congenital malformations.

Fetal Hydrops: Genetic Dissection of an Unspecific Sonographic Finding-A Comprehensive Review

Fetal hydrops is defined as the presence of abnormal fluid collections in two or more intra-fetal compartments. It has been classified based on etiology (immune vs. non-immune), on the presence or absence of other findings (isolated vs. non-isolated) and on the gestational age at presentation (first-, second- or third-trimester). In all cases of non-immune hydrops fetalis, invasive prenatal diagnosis is offered. However, after cytogenetic analyses, 80% of fetuses remain without etiological diagnosis, not allowing one to define the prognosis and to formulate recurrence risks. Several geneticists recommend performing either a next-generation sequencing panel (commonly limited to RASopathy testing) or exome sequencing, if cytogenetic tests are inconclusive. In the literature, the data are extremely heterogeneous, due to the differences in these indications and the limitation of study to a select group of genes. The identification of the underlying cause is crucial, as prognostic information and even therapy options are becoming increasingly available for a wide and growing array of genetic conditions. A systematic approach would allow an overall evaluation of the diagnostic rate of the exome sequencing in fetal effusions, also calculating the prevalence of associated diseases, with the aim of obtaining a diagnosis, defining the most appropriate management for each case, and broadening the spectrum of conditions known to be associated with hydrops.

Exome sequencing for nonimmune hydrops fetalis and clinical utility of data reanalysis

BACKGROUND

Nonimmune hydrops fetalis (NIHF) presents as life-threatening fluid collections in multiple fetal compartments and may be led by numerous etiologies.

AIM

To establish the diagnostic yield of exome sequencing for single-gene disorders in unexplained NIHF and to evaluate the clinical utility of data reanalysis.

METHODS

A series of 53 unexplained cases of NIHF were enrolled, including 39 cases met a strict definition of NIHF and 14 cases with increased nuchal translucency (NT) and/or cystic hygroma in combination with other fluid collections. Trio ES from fetal samples and parental blood was performed, and clinical reports were returned by geneticists and genetic counselors. Multidisciplinary team forums were conducted for accurate diagnoses and improved patient management. The clinical follow-up assessments were conducted, and the reanalysis was performed for cases with a non-positive result.

RESULTS

Diagnostic variants were identified in 22.6% (12/53) of the cases, and variants of potential clinical significance were detected in an additional 13.2% (7/53) of the cases. Of them, three possible diagnoses (3/41, 7.3%) were obtained during reanalysis. Notably, half of the diagnosed cases were from the group exhibiting only skin edema and increased NT and/or cystic hygroma. The diagnostic rate in this group was 42.8% (6/14), while in the classically defined NIHF group, the rate was 15.4% (6/39). The pregnancy termination and live birth rates of the cases with positive genetic testing results were found to be statistically significantly different from those with negative results (91.7% vs. 53.6% and 8.3% vs. 36.6%, P < 0.05 for both).

CONCLUSION

ES provides high incremental diagnostic yield for NIHF after standard-of-care testing, and reevaluating non-diagnostic exomes in light of updated knowledge can maximize diagnostic yield. Identifying the etiology of NIHF facilitates prenatal diagnosis, improves the management of NIHF cases and predicts recurrence risk in future pregnancies.

Hydrops fetalis due to loss of function of hNav1.4 channel via compound heterozygous variants

Hydrops fetalis, characterized by abnormal fluid accumulation in fetuses, presents a significant risk of stillbirth and neonatal mortality. Although the etiology of nonimmune hydrops fetalis (NIHF) is multifaceted, recent studies have highlighted genetic factors as crucial determinants. This study focused on a family with three consecutive stillbirths, each with pronounced hydrops fetalis. Using whole-exome sequencing (WES), we identified compound heterozygous variants of the SCN4A gene encoding the voltage-gated sodium channel of the skeletal muscle (hNav1.4), c.2429T>A p.L810Q and c.4556T>C p.F1519S, in all three deceased infants. A functional analysis conducted using the whole-cell patch-clamp technique revealed loss-of-function defects in both variant channels, with F1519S exhibiting a complete loss of ionic current and L810Q showing a reduced channel opening. These findings support the pathogenicity of SCN4A variants in NIHF and underscore the significance of functional studies in elucidating genotype-phenotype correlations. Furthermore, our study emphasizes the diagnostic value of WES in cases of NIHF in where standard genetic testing fails to identify causative variants.

Parvovirus B19 in Pregnancy-Do We Screen for Fifth Disease or Not?

Parvovirus B19 (B19V) infection is the cause of erythema infectiosum, or the "fifth disease", a widespread infection, potentially affecting 1-5% of pregnant women, in most cases without significant damage to the pregnancy or fetus. It follows a seasonal variation, with a higher prevalence in temperate climates, mainly in late winter and early spring. Women at increased risk include mothers of preschool and school-age children, and those working in nurseries, kindergartens, and schools. Vertical transmission occurs in 33% to 51% of cases of maternal infection. Parvovirus infection is an important cause of fetal perinatal infection resulting in increased morbidity through the development of fetal anemia, heart failure, and non-immune hydrops. A comprehensive literature review was conducted using PubMed, Cochrane Library, and Google Scholar, focusing on publications from the last 10 years and prioritizing studies related to parvovirus B19 infection in pregnancy. We summarized the existing data in the literature on the effects of parvovirus B19 infection during pregnancy and weighed if there is a need for screening in pregnant patients. Routine screening for parvovirus B19 infection can be considered in communities where infection is common, there is occupational exposure, or during endemic periods, with the reason being that accurate identification and treatment of fetuses affected by congenital B19V infection have been shown to improve perinatal outcomes.

Undiagnosed mirror syndrome with maternal hypoxemia onset during an emergency cesarean section: A case report

RATIONALE

Mirror syndrome is a rare pregnancy condition in which maternal edema is associated with fetal hydrops. Because of its rarity and overlapping symptoms, this condition is often misdiagnosed as another pregnancy complication.

PATIENT CONCERNS

A 28-year-old pregnant Japanese woman presented with sudden 7.5-kg weight gain, leg edema, and increased d-dimer level.

DIAGNOSES

Ultrasound revealed polyhydramnios and fetal hydrops, and findings of maternal edema and blood test results were suggestive of Miller syndrome. Although, the patient was initially misdiagnosed due to a lack of information and the rarity of this disease.

INTERVENTIONS

An emergency cesarean section was performed under spinal anesthesia at 36 weeks and 2 days of- pregnancy. We could not diagnose mirror syndrome.

OUTCOMES

The newborn's Apgar scores were 2 and 5 at 1 and 5 minutes after delivery, respectively. The patient's SpO2 suddenly decreased to 86% during cesarean section and persisted for 2 days. Chest computed tomography revealed pleural effusion and pulmonary edema. The pleural effusions and lung edema spontaneously resolved after the cesarean section.

LESSONS

This case reports on Miller syndrome with maternal hypoxemia onset during an emergency cesarean section and highlights the potential for better perioperative management and improvement in maternal mortality through prompt diagnosis and appropriate treatment shared not only among obstetricians and pediatricians but also among anesthesiologists.

Arterial and Venous Doppler in Evaluation of the "At-risk" Fetus

Our practice utilizes Doppler ultrasound as one of the most objective and effective methods to assess at-risk pregnancies. This review will discuss the application of arterial and venous Doppler techniques in assessing and managing various diseases and conditions for high-risk fetuses.

Non-immune hydrops fetalis is associated with bi-allelic pathogenic variants in the MYB Binding Protein 1a (MYBBP1A) gene

Non-immune hydrops fetalis (NIHF) is a rare entity characterized by excessive accumulation of fluid within the fetal extravascular compartments and body cavities. Here we present two intrauterine fetal demises with NIHF presenting with oligohydramnios, cystic hygroma, pleural effusion, and generalized hydrops with predominance of subcutaneous edema. The fetuses also presented with ascites, severe and precocious IUGR and skeletal anomalies. Whole exome sequencing was applied in order to screen for a possible genetic cause. The results identified biallelic variants in MYBBP1A in both fetuses. A previous report described another case with a similar phenotype having compound heterozygous variants in the same gene. The protein encoded by MYBBP1A is involved in several cellular processes including the synthesis of ribosomal DNA, the response to nucleolar stress, and tumor suppression. Our functional protein analysis through immunohistochemistry indicates that MYBBP1A is a gene expressed during fetal stages. Altogether, we concluded that MYBBP1A is associated with the development of hydrops fetalis. More cases and further studies are necessary to understand the role of this gene and the mechanism associated with NIHF.

Growth velocity of fetal sacrococcygeal teratoma as predictor of perinatal morbidity and mortality: multicenter study

OBJECTIVE

To identify prenatal predictors of poor perinatal outcome in fetuses with isolated sacrococcygeal teratoma (SCT).

METHODS

This was a retrospective study of fetuses with isolated (non-syndromic) SCT managed at one of five pediatric surgery and/or fetal medicine centers between January 2007 and December 2017. The primary outcome was the occurrence of poor perinatal outcome, defined as prenatal death (including termination), or neonatal death or severe compromise (hemorrhagic shock). Data regarding prenatal diagnosis (sonographic features both at referral and at the last ultrasound examination before pregnancy outcome, assessment of SCT growth velocity), perinatal complications and outcome, and neonatal course were analyzed to determine prenatal SCT characteristics associated with adverse perinatal outcome.

RESULTS

Fifty-five fetuses were included, diagnosed with isolated SCT at a median gestational age of 22 (interquartile range, 18-23) weeks. There was a poor perinatal outcome in 31% (n = 17) of these cases, including intrauterine fetal demise (4%, n = 2), pregnancy termination (13%, n = 7) and neonatal severe compromise (15%, n = 8), leading to neonatal death in five cases. The overall survival rate after prenatal diagnosis of isolated SCT was 75% (n = 41 of 55). Earlier gestational age at diagnosis (P = 0.02), large tumor volume at referral (P < 0.001), presence of one or more hemodynamic complications (P = 0.02), fast tumor growth velocity (P < 0.001) and high tumor grade (highest tumor grade ≥ 3) (P = 0.049) were associated with poor perinatal outcome on univariate analysis. On stepwise logistic regression analysis, tumor growth velocity was the only remaining independent factor associated with poor perinatal outcome (odds ratio (OR) (per 1-mm/week increase), 1.48 (95% CI, 1.22-1.97), P = 0.001). The best predictive cut-off of tumor growth velocity for poor perinatal outcome was 7 mm/week (OR, 25.7 (95% CI, 5.6-191.3), P < 0.001), yielding a sensitivity of 88% and a specificity of 77%.

CONCLUSIONS

Approximately 30% of fetuses with a diagnosis of isolated SCT have poor perinatal outcome. Tumor growth velocity ≥ 7 mm/week appears to be an appropriate discriminative cut-off for poor perinatal outcome. These results could help to inform prenatal management and counseling of parents with an affected pregnancy. © 2024 The Author(s). Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Birth in the Operating Room for Immediate Cardiac Surgery: A Rare but Effective Strategy

Background: With significant advancements in fetal cardiac imaging, patients with complex congenital heart disease (CHD) carrying a high risk for postnatal demise are now being diagnosed earlier. We sought to assess an interdisciplinary strategy for delivering these children in an operating room (OR) adjacent to a cardiac OR for immediate surgery or stabilization. Methods: All children prenatally diagnosed with CHD at risk for immediate postnatal hemodynamic instability and cardiogenic shock who were delivered in the operating room (OR) between 2012 and 2023 in which the senior author was consulted were included. Results: Eight patients were identified. Six (75%) patients were operated on day-of-life zero, all requiring obstructed total anomalous pulmonary venous return (TAPVR) repair. Of these six patients, 2 (33%) required a simultaneous Norwood procedure, 2 (33%) required pulmonary artery unifocalization and modified Blalock-Taussig-Thomas shunt, and 2 (33%) patients had repair of obstructed mixed TAPVR. The remaining 2 patients potentially planned for immediate surgery had nonimmune hydrops fetalis and went into cardiogenic shock at 12 and 72 hours postnatally, requiring a novel Norwood procedure with left-ventricular exclusion for severe aortic/mitral valve insufficiency. The median ventilation and inpatient durations were 19 [IQR: 11-26] days and 41 [IQR: 32-128] days, respectively. Three(38%) patients required one or more in-hospital reoperations. Subsequent staged procedures included Glenn (n = 5), Fontan (n = 3), biventricular repair (n = 2), ventricular assist device placement (n = 1), and heart transplant (n = 1). Median follow-up was 5.7 [IQR:1.3-7.8] years. The five-year postoperative survival was 88% (n = 7/8). Conclusion: While children with these diagnoses have historically had poor survival, the strategy of birth in the OR adjacent to a cardiac OR where emergent surgery is planned is a potentially promising strategy with excellent clinical outcomes. However, this is a high-resource strategy whose feasibility in any program requires thoughtful assessment.

Maternal implications of fetal anomalies: a population-based cross-sectional study

BACKGROUND

Although it is well-known that the presence of fetal anomalies is associated with maternal morbidity, granular information on these risks by type of anomaly is not available.

OBJECTIVE

To examine adverse maternal outcomes according to the type of fetal anomaly.

STUDY DESIGN

This was a repeated cross-sectional analysis of US vital statistics Live Birth/Infant Death linked data from 2011 to 2020. All pregnancies at 20 weeks or greater were included. Our primary outcome was severe maternal morbidity (SMM), defined as any maternal intensive care unit admission, transfusion, uterine rupture, or hysterectomy. Outcomes were compared between pregnancies with a specific type of fetal anomaly and pregnancies without any fetal anomaly. Fetal anomalies that were available in the dataset included anencephaly, meningomyelocele/spina bifida, cyanotic congenital heart disease, congenital diaphragmatic hernia, omphalocele, gastroschisis, cleft lip and/or palate, hypospadias, limb anomaly, and chromosomal disorders. If a fetus had more than one anomaly, it was classified as multiple anomalies. Adjusted relative risks (aRR) with 99% confidence intervals (99% CI) were calculated using modified Poisson regression. Adjusted risk differences (aRDs) were calculated using the marginal standardization form of predictive margins.

RESULTS

Of 35,760,626 pregnancies included in the analysis, 35,655,624 pregnancies had no fetal anomaly and 105,002 had isolated or multiple fetal anomalies. Compared to pregnancies without fetal anomaly, all fetal anomalies were associated with an increased risk of SMM except for gastroschisis and limb anomaly in order of aRRs (99% CI): 1.58 (1.29-1.92) with cleft lip and/or palate; 1.75 (1.35-2.27) with multiple anomalies; 1.76 (1.18-2.63) with a chromosomal disorder; 2.19 (1.82-2.63) with hypospadias; 2.20 (1.51-3.21) with spina bifida; 2.39 (1.62-3.53) with congenital diaphragmatic hernia; 2.66 (2.27-3.13) with congenital heart disease; 3.15 (2.08-4.76) with omphalocele; and 3.27 (2.22-4.80) with anencephaly. Compared to pregnancies without fetal anomaly, all fetal anomalies were associated with an increased absolute risk of SMM except for gastroschisis and limb anomaly in order of aRDs (99% CI): 0.26 (0.12-0.40) with cleft lip and/or palate, 0.34 (0.13-0.55) with multiple anomalies, 0.34 (0.02-0.66) with a chromosomal disorder, 0.54 (0.36-0.72) with hypospadias, 0.54 (0.17-0.92) with spina bifida, 0.63 (0.21-1.05) with congenital diaphragmatic hernia, 0.75 (0.56-0.95) with congenital heart disease, 0.97 (0.38-1.56) with omphalocele, and 1.03 (0.46-1.59) with anencephaly.

CONCLUSION

The presence of fetal anomalies is associated with adverse maternal health outcomes. The risk of SMM varies according to the type of fetal anomaly. Counseling mothers about the maternal implications of fetal anomalies is paramount to help them make informed decisions regarding their pregnancy outcome.

Prenatal Phenotype of Alkuraya-Kučinskas Syndrome: A Novel Case and Systematic Literature Review

Alkuraya-Kučinskas syndrome (AKS) is an autosomal recessive multisystem disorder resulting from mutations in the BLTP1 gene, formerly known as KIAA1109. Primary manifestations include brain malformations, arthrogryposis, and clubfeet. Cardiac, renal, and ophthalmologic abnormalities may also be observed, while nonimmune hydrops is rare. We present a case of two novel BLTP1 canonical splice-site variants in a fetus with multiple congenital anomalies, including hydrops, a kinked brainstem, and joint contractures. A systematic literature review was conducted to describe the prenatal phenotype of AKS, which was inspired by our case. Our systematic literature review of the prenatal phenotype in 19 cases, including our additional case, demonstrated joint contractures in 90% (18/20), ventriculomegaly in 60% (12/20), brainstem dysgenesis in 50% (10/20), cerebellar hypoplasia in 50% (10/20), parenchymal thinning with lissencephalic aspect in 60% (12/20), and facial dysmorphism in 70% (14/20) of reported AKS cases. In addition to our case, hydrops was reported in two other families. AKS should be considered in fetal presentations with characteristic features, especially brainstem kinking and joint contractures. Exome sequencing, including coverage of canonical intronic splice-site variants, can clarify the diagnosis. TRIAL REGISTRATION: ClinicalTrials.gov registration: NCT03911531.

Galactosialidosis presenting as non-immune hydrops

Hydrops fetalis is an abnormal accumulation of fluid in two or more foetal compartments which is easily detected using prenatal ultrasonography. It can be categorised into immune and non-immune. The non-immune hydrops can result from various aetiologies, including cardiovascular, respiratory, genitourinary infections, chromosomal anomalies and metabolic causes. The metabolic causes, including lysosomal storage disorders (LSD), are increasingly being recognised as the causes of non-immune hydrops. The hydrops fetalis associated with metabolic disorders is usually severe with huge ascites, hepatosplenomegaly, thick skin, renal abnormalities, increased nuchal translucency, renal abnormalities and skeletal deformities. In this report, we describe a case of LSD, that is, galactosialidosis presenting as non-immune hydrops and its diagnosis. In utero diagnosis of the disorder without an index case is challenging. The definitive diagnosis is important for planning and management of future conceptions.

Severe generalized edema in a premature neonate: A case report and literature review

Key Clinical Message

With no family history, and an atypical phenotype, the clinical diagnosing of Noonan syndrome (NS) can be very difficult. The present case emphasized that generalized edema in neonates may be the potential first symptom of NS.

Abstract

Severe generalized edema is a rare pathological condition with high mortality in newborns, in particular the premature infants. It is characterized by the extensive subcutaneous tissue edema and the accumulation of fluid in neonatal body fluid compartments. The etiology and pathogenesis of hydrops in neonates are quite complex. Generally speaking, hydrops can be divided into immune hydrops and non-immune hydrops according to the etiology. It is still challenging in treating severe neonatal edema. In this study, we presented a preterm newborn with severe generalized edema after birth, which was finally diagnosed with Noonan syndrome (NS). The infant clinically manifested as severe generalized edema alone, without the involvement of multiple organ malformation. Generalized edema in neonates was probably the first symptom of NS. Therefore, differential diagnosis of NS is necessary for infants developing generalized edema.

Nonimmune Hydrops Fetalis

Nonimmune hydrops fetalis (NIHF) poses a significant challenge in perinatal care due to its high mortality rates and diverse etiologies. This comprehensive review examines the pathophysiology, etiology, antenatal diagnosis and management, postnatal care, and outcomes of NIHF. NIHF arises from numerous underlying pathologies, including genetic disorders, cardiovascular causes, and fetal infections, with advances in diagnostic techniques improving identification rates. Management strategies include termination of pregnancy for severe cases and fetal therapy for selected treatable etiologies, and neonatal care involves assessing and treating fluid collections and identifying underlying causes. Prognosis depends on factors such as gestational age at diagnosis and the extent of resuscitation needed, with challenges remaining in improving outcomes for affected infants.

Maternal "mirror" syndrome: Evaluating the benefits of fetal therapy

OBJECTIVE

To evaluate maternal and perinatal outcomes following fetal intervention in the context of maternal "mirror" syndrome.

STUDY DESIGN

A multicenter retrospective study of all cases of fetal hydrops complicated by maternal "mirror" syndrome and treated by any form of fetal therapy between 1995 and 2022. Medical records and ultrasound images of all cases were reviewed. "Mirror" syndrome was defined as fetal hydrops and/or placentomegaly associated with the maternal development of pronounced edema, with or without pre-eclampsia. Fetal hydrops was defined as the presence of abnormal fluid collections in ≥2 body cavities.

RESULTS

Twenty-one pregnancies met the inclusion criteria. Causes of fetal hydrops and/or placentomegaly included fetal lung lesions (n = 9), twin-twin transfusion syndrome (n = 6), severe fetal anemia (n = 4), and others (n = 2). Mean gestational age at "mirror" presentation was 27.0 ± 3.8 weeks. Maternal "mirror" syndrome was identified following fetal therapeutic intervention in 14 cases (66.6%). "Mirror" symptoms resolved or significantly improved before delivery in 8 (38.1%) cases with a mean interval from fetal intervention to maternal recovery of 13.1 days (range 4-35). Three women needed to be delivered because of worsening "mirror" syndrome. Of the 21 pregnancies treated (27 fetuses), there were 15 (55.5%) livebirths, 7 (25.9%) neonatal deaths and 5 (18.5%) intra-uterine deaths.

CONCLUSION

Following successful treatment and resolution of fetal hydrops, maternal "mirror" syndrome can improve or sometimes completely resolve before delivery. Furthermore, the recognition that "mirror" syndrome may arise only after fetal intervention necessitates hightened patient maternal surveillance in cases of fetal hydrops.

Glucose-6-phosphate dehydrogenase deficiency as a cause for nonimmune hydrops fetalis and severe fetal anemia: A systematic review

BACKGROUND

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is an X-linked recessive disorder that predisposes individuals to hemolysis due to an inborn error of metabolism. We performed a systematic literature review to evaluate G6PD deficiency as a possible etiology of nonimmune hydrops fetalis (NIHF) and severe fetal anemia.

METHODS

PubMed, OVID Medline, Scopus, and clinicaltrials.gov were queried from inception until 31 April 2023 for all published cases of NIHF and severe fetal anemia caused by G6PD deficiency. Keywords included "fetal edema," "hydrops fetalis," "glucose 6 phosphate dehydrogenase deficiency," and "fetal anemia." Cases with workup presuming G6PD deficiency as an etiology for NIHF and severe fetal anemia were included. PRISMA guidelines were followed.

RESULTS

Five cases of G6PD-related NIHF and one case of severe fetal anemia were identified. Four fetuses (4/6, 66.7%) were male and two fetuses (2/6, 33.3%) were female. Mean gestational age at diagnosis of NIHF/anemia and delivery was 32.2 ± 4.9 and 35.7 ± 2.4 weeks, respectively. Four cases (66.7%) required a cordocentesis for fetal transfusion, and two cases (33.3%) received blood transfusions immediately following delivery. Among the four multigravida cases, two (50%) noted previous pregnancies complicated by neonatal anemia. When reported, the maternal cases included two G6PD deficiency carrier patients and two G6PD-deficient patients. Exposures to substances known to cause G6PD deficiency-related hemolysis occurred in 3/6 (50%) cases.

CONCLUSION

Six cases of NIHF/severe fetal anemia were associated with G6PD deficiency. While G6PD deficiency is an X-linked recessive condition, female fetuses can be affected. Fetal G6PD deficiency testing can be considered if parental history indicates, particularly if the standard workup for NIHF is negative.

Fetal Hydrops Associated With 47,XXX: A Case Report and Literature Review

This report aims to investigate the association between 47,XXX and fetal hydrops by examining a clinical case and performing a comprehensive review of the relevant literature. A 34-year-old Japanese woman, gravida 2, para 1, was diagnosed with fetal hydrops at 27 weeks' gestation. Prenatal testing revealed a 47,XXX karyotype. Interventions included thoracocentesis and a thoracoamniotic shunt. A cesarean delivery was performed at 34 weeks and the female neonate initially had respiratory challenges. After 69 days in the neonatal intensive care unit, the infant was discharged in stable condition, and the 47,XXX karyotype was confirmed. This case may add evidence suggesting an association between 47,XXX and fetal hydrops. Chromosomal abnormalities are causes of fetal hydrops, but its association with 47,XXX remains unclear. Providing comprehensive information on this condition to couples is crucial, and considering the inclusion of fetal hydrops in the list of associated conditions might be advisable.

Trends in Procedures in the Neonatal Intensive Care Unit

OBJECTIVE

The aim of the study is to identify the rates and trends of various procedures performed on newborns.

STUDY DESIGN

The Healthcare Cost and Utilization Project (HCUP) database for the years 2002 to 2015 was queried for the number of livebirths, and various procedures using International Classification of Diseases, Ninth Revision (ICD-9) codes. These were adjusted to the rate of livebirths in each particular year. A hypothetical high-volume hospital based on data from the last 5 years was used to estimate the frequency of each procedure.

RESULTS

Over the study period, there was a decline in the rates of exchange transfusions and placement of arterial catheters. There was an increase in the rates of thoracentesis, abdominal paracentesis, placement of umbilical venous catheter (UVC) lines, and central lines with ultrasound or fluoroscopic guidance. No change was observed in the rates of unguided central lines, pericardiocentesis, bladder aspiration, intubations, and LP. Intubations were the most performed procedures. Placement of UVC, central venous lines (including PICCs), arterial catheters, and LP were relatively common, whereas others were rare such as pericardiocentesis and paracentesis.

CONCLUSION

Some potentially lifesaving procedures are extremely rare or decreasing in incidence. There has also been an increase in utilization of fluoroscopic/ultrasound guidance for the placement of central venous catheters.

KEY POINTS

· Advances in neonatal care have impacted the number of procedures performed in the NICU.. · It is unclear whether invasive procedures occur at rates sufficient for adequate training and maintenance of skills.. · Understanding the NICU procedural trends is important in designing simulation and competency-based medical education programs..

Parvovirus B19 in Pregnancy

Importance

Although the risk of parvovirus B19 infection during pregnancy and subsequent risk of adverse fetal outcome are low, understanding management practices is essential for proper treatment of fetuses with nonimmune hydrops fetalis. In addition, continued investigation into delivery management, breastfeeding recommendations, and congenital abnormalities associated with pregnancies complicated by parvovirus B19 infection is needed.

Objective

This review describes the risks associated with parvovirus B19 infection during pregnancy and the management strategies for fetuses with vertically transmitted infections.

Evidence Acquisition

Original articles were obtained from literature search in PubMed, Medline, and OVID; pertinent articles were reviewed.

Results

Parvovirus B19 is a viral infection associated with negative pregnancy outcomes. Up to 50% of people of reproductive age are susceptible to the virus. The incidence of B19 in pregnancy is between 0.61% and 1.24%, and, overall, there is 30% risk of vertical transmission when infection is acquired during pregnancy. Although most pregnancies progress without negative outcomes, viral infection of the fetus may result in severe anemia, congestive heart failure, and hydrops fetalis. In addition, vertical transmission carries a 5% to 10% chance of fetal loss. In pregnancies affected by fetal B19 infection, Doppler examination of the middle cerebral artery peak systolic velocity should be initiated to surveil for fetal anemia. In the case of severe fetal anemia, standard fetal therapy involves an intrauterine transfusion of red blood cells with the goal of raising hematocrit levels to approximately 40% to 50% of total blood volume. One transfusion is usually sufficient, although continued surveillance may indicate the need for subsequent transfusions. There are fewer epidemiologic data concerning neonatal risks of congenital parvovirus, although case reports have shown that fetuses with severe anemia in utero may have persistent anemia, thrombocytopenia, and edema in the neonatal period.

Conclusions and Relevance

Parvovirus B19 is a common virus; seropositivity in the geriatric population reportedly reaches 85%. Within the pregnant population, up to 50% of patients have not previously been exposed to the virus and consequently lack protective immunity. Concern for parvovirus B19 infection in pregnancy largely surrounds the consequences of vertical transmission of the virus to the fetus. Should vertical transmission occur, the overall risk of fetal loss is between 5% and 10%. Thus, understanding the incidence, risks, and management strategies of pregnancies complicated by parvovirus B19 is essential to optimizing care and outcomes. Further, there is currently a gap in evidence regarding delivery management, breastfeeding recommendations, and the risks of congenital abnormalities in pregnancies complicated by parvovirus B19. Additional investigations into optimal delivery management, feeding plans, and recommended neonatal surveillance are needed in this cohort of patients.

Prenatal Management and Perinatal Outcome in a Large Series of Hydrops Fetalis

INTRODUCTION

Nonimmune hydrops fetalis (NIHF) is the most frequent etiology of hydrops fetalis (HF), accounting for around 95% of cases. It associates high perinatal mortality and morbidity rates. The aim of the study was, first, to investigate etiology, prenatal management, and perinatal outcome in a large single-center series of HF; second, to identify prenatal prognostic factors with impact on perinatal outcome.

MATERIALS AND METHODS

Observational retrospective study of 80 HF diagnosed or referred to a single tertiary center between 2012 and 2021. Clinical characteristics, etiology, prenatal management, and perinatal outcome were recorded. Adverse perinatal outcome was defined as intrauterine fetal death (IUFD), early neonatal death (first 7 days of life) and late neonatal death (between 7 and 28 days).

RESULTS

Seventy-six of the 80 cases (95%) were NIHF, main etiology being genetic disorders (28/76; 36.8%). A total of 26 women (32.5%) opted for termination of pregnancy, all of them in the NIHF group. IUFD occurred in 24 of 54 patients (44.4%) who decided to continue the pregnancy. Intrauterine treatment was performed in 29 cases (53.7%). There were 30 newborns (55.6%). Adverse perinatal outcome rate was 53.7% (29/54), significantly higher in those diagnosed <20 weeks of gestation (82.4% < 20 weeks vs. 40.5% ≥ 20 weeks; p = 0.004). Survival rate was higher when fetal therapy was performed compared to the expectantly managed group (58.6% vs. 32%; p = 0.05). Intrauterine blood transfusion and thoraco-amniotic shunt were the procedures that achieved the highest survival rates (88.9% and 100%, respectively, p = 0.003).

CONCLUSION

NIHF represented 95% of HF with genetic disorders as the main etiology. Most of them were diagnosed before 20 weeks of gestation, with worse prognosis than cases detected later in gestation. Rates of TOP, IUFD, and early neonatal death were higher in NIHF. Intrauterine therapy, when indicated, improved the perinatal outcome.

Maternal outcomes of a cohort of pregnancies affected by non-immune hydrops fetalis

OBJECTIVE

To describe the maternal outcomes of a prospective cohort of non-immune hydrops fetalis (NIHF) pregnancies with negative standard-of-care evaluations.

METHODS

This study was a secondary analysis of a prospective cohort study of NIHF pregnancies with negative work-ups (infection, alloimmune anemia, fetomaternal hemorrhage, and chromosomal disorders). Outcomes were obstetric complications, including pre-eclampsia, mirror syndrome, preterm birth, polyhydramnios, postpartum hemorrhage, and maternal mental health.

RESULTS

Forty pregnancies were included. Four patients developed pre-eclampsia (4/40, 10.0%); three occurred postpartum. None was diagnosed with mirror syndrome. Of the 31 continued pregnancies, 16 (51.6%) resulted in early fetal death or stillbirth and 15 (48.4%) resulted in live births. Of the 15 live births, 8 (53.3%) were delivered by primary cesarean delivery; 5 (62.5%) were for hydrops fetalis. Eleven live births (73.3%) were delivered preterm; 9 (81.8%) were indicated, most commonly for fetal indications (7/9, 77.8%). Polyhydramnios occurred in 14/40 (35.0%) cases. Where EBL was recorded (n=37), there were 5 (13.5%) cases of postpartum hemorrhage and an additional 3 (8.1%) had uterine atony without hemorrhage. Eighteen patients (18/40, 45.0%) had new-onset or exacerbated depression or anxiety symptoms.

CONCLUSION

Our study identified several important adverse outcomes of pregnancies complicated by NIHF with negative standard-of-care evaluations, including a high rate of postpartum pre-eclampsia and worsened mental health. We identified a higher rate of cesarean delivery and preterm birth, both primarily for fetal indications. We also observed the known relationship between polyhydramnios, hemorrhage, and atony, but noted that this risk included pregnancies concluding in dilation and evacuation. Counseling after a diagnosis of NIHF should include these adverse outcomes.

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.

Perinatal Results and Long-Term Follow-Up of Fetal Cardiac Tumors: A 30-Year Historical Cohort Study

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.

A de novo homozygous missense mutation of the GUSB gene leads to mucopolysaccharidosis type VII identification in a family with twice adverse pregnancy outcomes due to non-immune hydrops fetalis

Non-immune hydrops fetalis (NIHF) is a common and severe manifestation of many genetic disorders. The ultrasound is an ideal method for diagnosing hydrops fetalis during pregnancy. Since most NIHFs do not have an identifiable cause, determining the underlying etiology remains a challenge for prenatal counseling. Due to advancements in exome sequencing, the diagnostic rates of NIHF have recently increased. As reported here, DNA was extracted from the amniotic fluid of a pregnant woman who was prenatally diagnosed with a NIHF type of unclear origin. Amniocentesis sampling demonstrated a normal female karyotype and copy number variation(CNVs) without alterations. Tri-whole exome sequencing (WES) was conducted to identify possible causative variants. In the fetus, a de novo genetic mutation was identified as a homozygous form. The mutation was located on the glucuronidase beta (GUSB) gene: NM_000181.3: c.1324G > A; p. Ala442Thr; Chr7:65439349, which leads to mucopolysaccharidosis type VII. This mutation was inherited from the parents and was first reported to be related to NIHF. We conclude that the use of WES is beneficial for NIHF cases whose prognosis has not been explained by standard genetic testing.

Mucopolysaccharidosis type VII (Sly syndrome) - What do we know?

Mucopolysaccharidosis type VII (MPS VII) is an ultra-rare, life-threatening, progressive disease caused by genetic mutations that affect lysosomal storage/function. MPS VII has an estimated prevalence of <1:1,000,000 and accounts for <3% of all MPS diagnoses. Given the rarity of MPS VII, comprehensive information on the disease is limited and we present a review of the current understanding. In MPS VII, intracellular glycosaminoglycans accumulate due to a deficiency in the lysosomal enzyme that is responsible for their degradation, β-glucuronidase, which is encoded by the GUSB gene. MPS VII has a heterogeneous presentation. Features can manifest across multiple systems and can vary in severity, age of onset and progression. The single most distinguishing clinical feature of MPS VII is non-immune hydrops fetalis (NIHF), which presents during pregnancy. MPS VII usually presents within one month of life and become more prominent at 3 to 4 years of age; key features are skeletal deformities, hepatosplenomegaly, coarse facies, and cognitive impairment, although phenotypic variation is a hallmark. Current treatments include hematopoietic stem cell transplantation and enzyme replacement therapy with vestronidase alfa. Care should be individualized for each patient. Development of consensus guidelines for MPS VII management and treatment is needed, as consolidation of expert knowledge and experience (for example, through the MPS VII Disease Monitoring Program) may provide a significant positive impact to patients.

Neonates with a prenatal diagnosis of hydrops fetalis: A 10-year experience in a tertiary care center

INTRODUCTION

Hydrops fetalis (HF) is a rare condition with a high mortality. This study analysed the obstetric and perinatal outcomes of antenatally diagnosed HF according to its aetiology and the possibility of intrauterine treatment (IUT).

PATIENTS AND METHODS

We carried out a retrospective review of the health records of 164 pregnant women with a prenatal diagnosis of HF in a tertiary care centre between 2011-2021. We analysed prenatal interventions, clinical findings, aetiologies and obstetric and live-born infant outcomes.

RESULTS

An invasive prenatal study had been performed in 79.3% cases. The most common aetiologies were genetic disorders (31%), TORCH and parvovirus B19 infections (9.7%) and structural heart diseases (9.1%). Intrauterine treatment was performed in 25.6%, and 74.4% of pregnancies were terminated. Pregnancies with a prenatal diagnosis of genetic or chromosomal disorders had higher rates of elective termination compared to other aetiologies (P < .01). Among all pregnancies, only 25.6% resulted in live births (LBs), most of them preterm. Perinatal and 1-year survival rates were higher in the group that received IUT (P < .001). Among the LBs, structural heart diseases had the worst survival rates, while the aetiology with the best outcomes was tachyarrhythmia. Survival at 1 year of life among those born alive was 70%, but 58.6% of these infants had significant morbidity at discharge.

CONCLUSIONS

Despite advances in the management of FH, the poor obstetric prognosis, perinatal mortality and morbidity of survivors is still significant. These data are important for the purpose of counselling families when HF is diagnosed antenatally.

The normality of the first-trimester placentae collected from elective terminations

Placentae collected from elective terminations during the first trimester are commonly used as control samples in research. However, it is widely acknowledged that many complications of pregnancies can occur or originate during the early stage of gestation. This raises the question that the placentae collected from the first trimester may not accurately reflect normal placental conditions. In this study, 95 placentae were collected from elective terminations and histology was performed. Out of these, 53 placentae (56 %) exhibited the typical structure of placental villi, indicating normal development. However, 42 placentae (44 %) showed placental hydrops, with varying degrees of severity (mild, moderate, or severe). Placental hydrops has been linked to several complicated pregnancies in the later stages of gestation. Our findings suggest that the development of pregnancy pathologies could start in the first trimester, as observed by the presence of hydrops. Placental researchers should be aware of when using first-trimester placentae from termination as controls in studies. However, it remains unclear whether pathological morphologies resolve or ameliorate as the pregnancy progression or whether such placentae continue to have such pathology, but clinical symptoms/signs do not manifest.

Amnioreduction vs expectant management in pregnancies with moderate to severe polyhydramnios

BACKGROUND

The rate of polyhydramnios is higher in pregnancies complicated by congenital anomalies. These pregnancies have higher rates of peripartum complications. Amnioreduction is offered to relieve maternal symptoms such as dyspnea, abdominal and respiratory discomfort, and other issues like satiety.

OBJECTIVE

This study aimed to report the rates of amnioreduction and its associated complications in pregnancies with moderate to severe polyhydramnios secondary to fetal anomalies. We also sought to determine if amnioreduction provided additional benefits, including prolongation of pregnancy and a decrease in the rates of peripartum morbidities associated with moderate to severe polyhydramnios.

STUDY DESIGN

This was a retrospective review of anomalous singleton pregnancies with moderate to severe polyhydramnios that were evaluated and delivered at a single center between 2013 and 2021. Peripartum outcomes were compared between pregnancies that underwent amnioreduction and those that were expectantly managed. Mann-Whitney U tests were used to compare continuous variables and Fisher's exact tests were used for categorical variables. A multiple regression model was created to understand the effects of amnioreduction on gestational age at delivery.

RESULTS

A total of 218 singleton pregnancies met the inclusion criteria of moderate to severe polyhydramnios in the study period. Of those, 110 patients (50.5%) underwent amnioreduction and 108 patients (49.5%) opted for expectant management. A total of 147 procedures were performed at a median gestational age of 32.5 weeks and a median of 1900 mL of amniotic fluid was removed per procedure. Complications occurred in 10.9% (n=16) of procedures, including preterm delivery within 48 hours in 5.4% cases (n=8). The median amniotic fluid index was higher in the amnioreduction group than in the expectant group (38.9 cm vs 35.5 cm; P<.0001). Patients who underwent amnioreduction had an earlier median gestational age at delivery (36.3 weeks vs 37.0 weeks; P=.048), however, the rates of spontaneous preterm delivery were similar. A higher percentage of women in the amnioreduction group had vaginal delivery (49.4% vs 30.5%; P=.01) and lower rates of uterine atony (2.4% vs 13.7%; P=.006). In the multiple linear regression analysis, the gestational age at delivery positively correlated with gestational age at amnioreduction after controlling for amniotic fluid volume (P<.0001; 95% confidence interval, 0.34-0.71). In addition, the patients in the amnioreduction group were twice as likely to have a vaginal delivery (P=.02).

CONCLUSION

Amnioreduction in the setting of moderate-severe polyhydramnios has a reasonably low rate of complications but does not provide any benefits in terms of prolonging the pregnancy. The procedure may increase the likelihood of vaginal delivery and lower the rates of uterine atony.

Intrauterine enzyme replacement therapies for lysosomal storage disorders: Current developments and promising future prospects

Lysosomal storage disorders (LSDs) are a group of monogenic condition, with many characterized by an enzyme deficiency leading to the accumulation of an undegraded substrate within the lysosomes. For those LSDs, postnatal enzyme replacement therapy (ERT) represents the standard of care, but this treatment has limitations when administered only postnatally because, at that point, prenatal disease sequelae may be irreversible. Furthermore, most forms of ERT, specifically those administered systemically, are currently unable to access certain tissues, such as the central nervous system (CNS), and furthermore, may initiate an immune response. In utero enzyme replacement therapy (IUERT) is a novel approach to address these challenges evaluated in a first-in-human clinical trial for IUERT in LSDs (NCT04532047). IUERT has numerous advantages: in-utero intervention may prevent early pathology; the CNS can be accessed before the blood-brain barrier forms; and the unique fetal immune system enables exposure to new proteins with the potential to prevent an immune response and may induce sustained tolerance. However, there are challenges and limitations for any fetal procedure that involves two patients. This article reviews the current state of IUERT for LSDs, including its advantages, limitations, and potential future directions for definitive therapies.

PIEZO1 is the most common monogenic etiology of non-immune hydrops fetalis detected by prenatal exome sequencing

OBJECTIVE

To clarify the relevance of PIEZO1 variants detected by prenatal exome in the context of non-immune hydrops fetalis (NIHF).

METHODS

A systematic review of prenatal exome studies from 1/1/2000-8/1/2022 was performed. Thirty-six studies met the inclusion criteria. PIEZO1 variants were categorized by disease mode (dominant (AD) versus recessive (AR)) and classified by the American College of Medical Genetics and Genomics (ACMG) guidelines.

RESULTS

Twenty-two pregnancies with 35 distinct PIEZO1 variants were included. We deemed PIEZO1 variants to be "likely diagnostic" in 12/22 pregnancies, "possibly diagnostic" in 7/22, and "unlikely diagnostic" in 3/22. In total, 19 of 191 NIHF cases diagnosed by prenatal exome were attributed to PIEZO1. Among likely diagnosed cases, the disease mode was AR in eight and AD in four. PIEZO1 variants causing AR NIHF were characterized by loss of function and isolated NIHF phenotype. PIEZO1 variants causing AD NIHF were characterized by gain of function in red blood cells, scarcity in databases, and sporadic inheritance. Missense variants associated with NIHF were clustered in three domains: transmembrane helical unit 4 (THU4), THU5, and the Cap.

CONCLUSION

PIEZO1 variants were reported in 10% of NIHF cases diagnosed by prenatal exome, making PIEZO1 the most common single gene reported in NIHF.

Adverse maternal outcomes associated with major fetal malformations after singleton live birth

BACKGROUND

Major fetal malformations complicate 2% to 5% of live births. It is unclear what effect fetal malformations have on severe maternal morbidity.

OBJECTIVE

This study aimed to compare maternal outcomes between individuals with a fetus with major or minor fetal malformations and those with a fetus without major or minor fetal malformations.

STUDY DESIGN

This was a secondary analysis of the Consortium on Safe Labor database. Our study was limited to the current analysis of pregnant individuals with a singleton live birth. Major fetal malformations based on the Centers for Disease Control and Prevention's criteria were defined. Fetal malformations that did not meet the criteria for major fetal malformations were categorized as minor fetal malformations. Our primary maternal outcome was severe maternal morbidity as defined by the Centers for Disease Control and Prevention. Missing values were imputed by multiple imputation using the k-nearest neighbor imputation method. Poisson regression with robust error variance was used to obtain adjusted relative risks with 95% confidence intervals, controlling for confounders.

RESULTS

Of 216,881 deliveries, there were 201,860 cases (93.1%) with no congenital malformation, 12,106 cases (5.6%) with minor fetal malformations, and 2845 cases (1.3%) with major fetal malformations. Compared with individuals with no fetal malformation, those with major fetal malformations were more likely to have severe maternal morbidity (0.7% vs 1.2%; adjusted relative risk, 1.51; 95% confidence interval, 1.07-2.12), postpartum hemorrhage (3.6% vs 6.9%; adjusted relative risk, 1.76; 95% confidence interval, 1.50-2.06), preeclampsia (5.1% vs 8.3%; adjusted relative risk, 1.48; 95% confidence interval, 1.31-1.67), and cesarean delivery (26.7% vs 42.3%; adjusted relative risk, 1.51; 95% confidence interval, 1.45-1.58). Compared with individuals with no fetal malformation, those with minor fetal malformations were more likely to have severe maternal morbidity (0.7% vs 1.4%; adjusted relative risk, 1.73; 95% confidence interval, 1.48-2.02), maternal death (0.01% vs 0.03%; adjusted relative risk, 4.50; 95% confidence interval, 1.18-17.19), postpartum hemorrhage (3.6% vs 6.1%; adjusted relative risk, 1.54; 95% confidence interval, 1.41-1.68), preeclampsia (5.1% vs 8.6%; adjusted relative risk, 1.50; 95% confidence interval, 1.41-1.60), superimposed preeclampsia (1.2% vs 2.4%; adjusted relative risk, 1.25; 95% confidence interval, 1.14-1.38), cesarean delivery (26.7% vs 39.6%; adjusted relative risk, 1.38; 95% confidence interval, 1.35-1.41), chorioamnionitis (3.0% vs 4.7%; adjusted relative risk, 1.41; 95% confidence interval, 1.29-1.53), and postpartum endometritis (0.6% vs 1.0%; adjusted relative risk, 1.58; 95% confidence interval, 1.31-1.90).

CONCLUSION

Major and minor congenital fetal malformations are independent risk factors for severe maternal morbidity and other pregnancy complications.

New Findings in the Multidisciplinary Management of a Fetal Intrapericardial Teratoma: A Case Report

INTRODUCTION

Fetal intrapericardial teratoma is a rare tumor that can be diagnosed by antenatal ultrasonography early in pregnancy.

CASE PRESENTATION

A fetal intrapericardial teratoma was detected on routine ultrasonography in the second trimester of pregnancy. At 31 weeks gestation, a marked increase in tumor size, fetal ascites, and pericardial effusion were observed, indicating that preterm delivery would be inevitable. Corticosteroid prophylaxis (24 mg of betamethasone in two doses of 12 mg 24 h apart) initiated for prophylaxis of respiratory distress syndrome led to a reduction in fetal ascites and pericardial effusion. Betamethasone therapy (4 mg/per day) was continued with the aim to postpone the expected date of delivery. Gestation was extended for more than 2 weeks. At 33 weeks and 5 days gestation, the neonate was delivered by elective cesarean section with ex utero intrapartum treatment and immediately submitted to fetal cardiac surgery. The infant was discharged from the hospital in good health about 4 months later.

CONCLUSION

The present report draws attention to improvement in fetal status and extension of gestation achieved with maternal low-dose corticosteroid therapy on antenatal ultrasound finding of fetal ascites and pericardial effusion due to intrapericardial teratoma.

The Cardiovascular Profile Score in Patients with Non-immune Hydrops Fetalis and Cardiac Anomalies - a Pilot Study

The purpose of this paper is to explore whether the cardiovascular profile score (CVPS) correlates with fetal outcome in patients with non-immune hydrops fetalis (NIHF) and cardiac anomalies. In this retrospective study, we included fetuses with NIHF and the suspicion of a cardiac anomaly in prenatal ultrasound. The CVPS was calculated using information obtained by fetal echocardiographic examination. Feto-neonatal mortality (FNM) was defined as intrauterine fetal demise or death in the first 6 months of life. We reviewed 98 patients, who were referred to the Department of Obstetrics and Gynecology of the Johannes Gutenberg University in Mainz with the diagnosis of NIHF between January 2007 and March 2021. By eighteen of them, the suspicion of a cardiac anomaly was raised. After exclusion of six pregnancies (one termination of pregnancy and five because of incomplete data), 12 cases were left for analysis. Mean gestational age at which the CVPS was calculated was 29 + 2 weeks. Two fetuses died in utero. Of the remaining ten hydropic fetuses, three newborns died in the neonatal period, and seven survived after a 6-month surveillance period. Median CVPS of all fetuses was 6 points. Surviving fetuses showed statistically significantly higher CVPS values (median 8 points) than fetuses with FNM (median 5 points, p value = 0.009). Our results point towards a positive association between CVPS and fetal outcome in fetuses with NIHF and cardiac anomalies. The CVPS appears to be a useful marker in the assessment of heart failure in utero.

Isolated non-immune hydrops fetalis: an observational study on complete spontaneous resolution, perinatal outcome, and long-term follow-up

PURPOSE

The aim of our study was to investigate spontaneous resolution and postnatal outcome in non-immune hydrops fetalis (NIHF). We specifically studied NIHF cases that occurred without any other anomalies in the prenatal diagnostic workup, defined as isolated NIHF (iNIHF).

METHODS

To identify iNIHF we retrospectively classified prenatal findings of 700 NIHF singletons, diagnosed in our prenatal referral center between 1997 and 2016. We studied the occurrence of prenatal resolution in iNIHF and linked it to the perinatal outcome. We obtained long-term outcome by contacting the parents, children, and the pediatricians and listed all functional and structural anomalies and temporary logopedic, psychosocial and motoric impairments.

RESULTS

Among 70 iNIHF cases, 54 (77.1%) resolved completely prenatally. The baby-take-home rate was 98.1% in these cases. In contrast, the baby-take-home rate in the subgroup without complete resolution was 25.0%. We achieved pediatric long-term outcome in 27 of 57 survivors (47.4%) of iNIHF with a mean follow-up period of 10.9 years. Among these 27 children, fetal hydrops had completely resolved prenatally in 26 cases and had regressed to a mild effusion in one case. In the pediatric development, two children had significant functional impairment and two children showed recurrent skin edema.

CONCLUSION

Complete spontaneous resolution was the most common intrauterine course of iNIHF in our collective. Completely resolved iNIHF had a favorable perinatal outcome in our study. Our data on the long-term outcomes are consistent with the assumption of an increased rate of functional impairments.

TRIAL REGISTRY

Internal study number of Heinrich-Heine-University, Duesseldorf: 6177R. Date of registration: December 2017.

Dual diagnosis of trisomy 21 and lethal perinatal Gaucher disease as a cause of non-immune hydrops fetalis in a twin pregnancy for a consanguineous couple

Non-immune hydrops is a prenatal finding which can occur due to an underlying genetic diagnosis such as common chromosomal aneuploidy (Trisomy 21, Turner syndrome etc.). It is extremely rare to have more than one genetic cause of hydrops fetalis in a single pregnancy. This report describes a dichorionic diamniotic pregnancy for a consanguineous couple where noninvasive prenatal testing was "high risk" for Trisomy 21. Family declined amniocentesis and opted for postnatal genetic testing. The pregnancy was later complicated with severe hydrops fetalis leading to demise for one of the twins, and a premature delivery of the other twin who had remarkable collodion not in keeping with Trisomy 21. Postnatal genetic investigations confirmed both Trisomy 21 and prenatal lethal Gaucher disease in the survivor twin. This case report highlights some of the prenatal diagnostic challenges for a consanguineous couple where a rare cause of fetal hydrops was concealed in a setting of a common chromosomal aneuploidy. The prompt postnatal diagnosis of perinatal lethal Gaucher disease, confirmed with undetectable glucocerebrosidase enzyme activity, assisted the family in the decision of providing palliative care for their infant who was quickly deteriorating. The importance of postnatal genetic evaluation and its impact on immediate patient management in an NICU setting is emphasized. This dual diagnosis was significant for the couple as it explained pervious pregnancy losses and has important future recurrence risk implications.

Understanding Preterm Birth in Pregnancies Complicated by Nonimmune Hydrops Fetalis

OBJECTIVE

Nonimmune hydrops fetalis (NIHF) is associated with poor perinatal outcomes including preterm birth (PTB). However, the frequency and causes of PTB in this population are not well understood. We hypothesized that NIHF frequently results in PTB due to medically indicated delivery for fetal distress.

STUDY DESIGN

This was a secondary analysis of a prospectively enrolled cohort of pregnancies with NIHF that underwent exome sequencing if standard testing was nondiagnostic. The primary outcome was frequency of PTB at <37 weeks' gestation. Secondary outcomes were reasons for PTB, fetal predictors of PTB, and frequency of neonatal death following PTB.

RESULTS

Fifty-six cases were included, with a median gestational age at delivery of 32.8 weeks (interquartile range [IQR]: 30.3-35.0). Overall, 86% (48/56) were delivered preterm. Among 48 PTBs, 18 (38%) were spontaneous, 9 (19%) were medically indicated for maternal indications (primarily preeclampsia), and 21 (44%) were medically indicated for fetal indications (nonreassuring antenatal testing or worsening effusions). Neither fetal genetic diagnosis nor polyhydramnios was associated with PTB.

CONCLUSION

More than four-fifths of pregnancies with NIHF result in PTB, often due to nonreassuring fetal status. These data are informative for counseling patients and for developing strategies to reduce PTB in pregnancies with NIHF.

KEY POINTS

· Pregnancies complicated by nonimmune hydrops fetalis often result in preterm birth.. · Preterm birth in these cases is most often medically indicated for fetal benefit.. · Fetal genetic conditions and polyhydramnios may be associated with preterm birth in cases of NIHF..

Investigation into the genetics of fetal congenital lymphatic anomalies

OBJECTIVE

Congenital lymphatic anomalies (LAs) arise due to defects in lymphatic development and often present in utero as pleural effusion, chylothorax, nuchal and soft tissue edema, ascites, or hydrops. Many LAs are caused by single nucleotide variants, which are not detected on routine prenatal testing.

METHODS

Demographic data were compared between two subcohorts, those with clinically significant fetal edema (CSFE) and isolated fetal edema. A targeted variant analysis of LA genes was performed using American College of Medical Genetics criteria on whole exome sequencing (WES) data generated for 71 fetal edema cases who remained undiagnosed after standard workup.

RESULTS

CSFE cases had poor outcomes, including preterm delivery, demise, and maternal preeclampsia. Pathogenic and likely pathogenic variants were identified in 7% (5/71) of cases, including variants in RASopathy genes, RASA1, SOS1, PTPN11, and a novel PIEZO1 variant. Variants of uncertain significance (VOUS) were identified in 45% (32/71) of cases. In CSFEs, VOUS were found in CELSR1, EPHB4, TIE1, PIEZO1, ITGA9, RASopathy genes, SOS1, SOS2, and RAF1.

CONCLUSIONS

WES identified pathogenic and likely pathogenic variants and VOUS in LA genes in 51% of fetal edema cases, supporting WES and expanded hydrops panels in cases of idiopathic fetal hydrops and fluid collections.

Genetic disorders and pregnancy outcomes of non-immune hydrops fetalis in a tertiary referral center

OBJECTIVES

Non-immune hydrops fetalis (NIHF) is a non-specific symptom associated with a wide range of disorders. The prognosis of NIHF depends on the underlying etiology. In this study, we investigated the incidence of chromosomal abnormalities and Bart's hydrops fetalis in pregnancies associated with NIHF in South China.

METHODS

We conducted a retrospective review of NIHF pregnancies referred to the Fujian Provincial Maternity and Children's Hospital between 2014 and 2018, excluding pregnancies with maternal alloimmunization. Routine karyotyping was performed on all 129 enrolled patients, and chromosomal microarray analysis was performed for 35 cases with a normal karyotype. In addition, α-thalassemia genotyping was performed to confirm the presence of Bart's hydrops fetalis.

RESULTS

Chromosomal abnormalities were detected in 29.5% (38/129) of the cohort, including 37 cases with aneuploidy and one case with unbalanced structural rearrangement. Chromosomal microarray analysis performed on the 35 cases with a normal karyotype did not reveal any additional pathogenic variants. The proportions of chromosomal abnormalities declined with trimester progression, with frequencies of 65%, 30.1%, and 8.3% in the first, second, and third trimesters, respectively (p < 0.05). Bart's hydrops fetalis was detected in 34.9% (45/129) of the cohort. Among the 46 (35.6%) cases with unknown etiology, 23 cases had other ultrasonic abnormalities characterized by poor outcomes, whereas seven cases with multiple cavity effusions that resolved or remitted prior to birth showed normal development during the 3-4 years of follow-up.

CONCLUSIONS

In South China, Bart's hydrops fetalis and chromosomal abnormalities are the most common genetic etiologies of NIHF. Generalized skin edema and accompanying ultrasonic abnormalities are predictive of adverse outcomes, highlighting the need for intensive monitoring and better pregnancy management of NIHF patients.

Neonatal Hemochromatosis: Systematic Review of Prenatal Ultrasound Findings—Is There a Place for MRI in the Diagnostic Process?

Neonatal hemochromatosis (NH) is an uncommon, severe disorder that results in fetal loss or neonatal death due to liver failure. NH is currently regarded as the phenotypic expression of gestational alloimmune liver disease (GALD). The diagnosis of NH-GALD is rarely prenatally established. In addition to providing a systematic review of the prenatal features that are identifiable using ultrasound (US) and MRI, we suggest a prenatal diagnosis algorithm for use in suspected NH during the first affected pregnancy. From a total of 586 database entries identified in PubMed, Google Scholar, and ResearchGate, we selected 18 studies published from 1993 to 2021 that reported maternal medical and obstetric history, prenatal ultrasound findings, and postpartum outcomes. We investigated the ultrasound and MRI features of these studies, along with the outcome due to this condition. A total of 74 cases were identified. The main reported prenatal US finding was fetal growth restriction (FGR) (33%), followed by oligohydramnios (13%) and hydrops fetalis (13%), with 13% cases described as uneventful. Other rare prenatal findings were fetal anemia, ascites, and abnormal fetal liver and spleen. Most pregnancies ended with fetal/perinatal death or therapeutic interruption of pregnancy. Favorable evolution with treatment (ensanguine transfusion and intravenous immunoglobulin (IVIG)) was reported for only 7% of fetuses. Using T2-weighted MRI, fetal extrahepatic siderosis confirmed prenatally in two cases and postnatally in 11 cases. IVIG treatment throughout subsequent pregnancies was found to significantly improve fetal prognosis. MRI should be indicated in selected cases of oligohydramnios, fetal hydrops, fetal hepatomegaly, ascites, or unexplained FGR or anemia after ruling out all other more frequently encountered conditions. MRI can be used to detect iron overload in the liver and extrahepatic siderosis.