Improved diagnosis in nonimmune hydrops fetalis using a standardized algorithm

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.

Biallelic ANGPT2 loss-of-function causes severe early-onset non-immune hydrops fetalis

BACKGROUND

Hydrops fetalis, a pathological fluid accumulation in two or more body compartments, is aetiologically heterogeneous. We investigated a consanguineous family with recurrent pregnancy loss due to severe early-onset non-immune hydrops fetalis.

METHODS AND RESULTS

Whole exome sequencing in four fetuses with hydrops fetalis revealed that they were homozygous for the angiopoietin-2 (ANGPT2) variant Chr8 (GRCh37/Hg19): 6385085T>C, NM_001147.2:c.557A>G. The substitution introduces a cryptic, exonic splice site predicted to result in loss of 10 nucleotides with subsequent shift in reading frame, leading to a premature stop codon. RNA analysis in the heterozygous parents demonstrated loss of detectable mutant allele, indicative of loss-of-function via nonsense-mediated mRNA decay. Serum ANGPT2 levels were reduced in the parents. In a pregnancy with a healthy, heterozygous child, transiently increased fetal nuchal translucency was noted.

CONCLUSION

Pathogenic heterozygous ANGPT2 missense variants were recently shown to cause autosomal dominant primary lymphoedema. ANGPT2 is a ligand of the TIE1-TIE2 (tyrosine kinase with immunoglobulin-like and epidermal growth factor-like domains 1 and 2) pathway. It is critical to the formation and remodelling of blood and lymphatic vessels and is involved in vessel maintenance. ANGPT2 knockout mice die from generalised lymphatic dysfunction. We show here that a homozygous pathogenic variant causes loss-of-function and results in severe early-onset hydrops fetalis. This is the first report of an autosomal recessive ANGPT2-related disorder in humans.

A single center experience in 90 cases with nonimmune hydrops fetalis: diagnostic categories ‒ mostly aneuploidy and still often idiopathic

OBJECTIVES

The prognosis of nonimmune hydrops fetalis (NIHF) is still poor with a high mortality and morbidity rate despite progress in perinatal care. This study was designed to investigate etiology and outcome of NIHF.

METHODS

A retrospective review of 90 NIHF cases from 2007 to 2019 was conducted at University Medical Center of the Johannes Gutenberg University, Mainz, Germany. Demographics, genetic results, prenatal and postnatal outcomes including one year survival as well as autopsy data were extracted. Etiology of hydrops was classified using 13 previously established categories. In 4 patients observed between 2016 and 2019, we used a next-generation-sequencing (NGS) panel for genetic evaluation.

RESULTS

Ninety NIHF cases were identified, with a median gestational age (GA) at diagnosis of 14 weeks. There were 25 live-born infants with a median GA of 34 weeks at birth, 15 patients survived to one year. There was aneuploidy in more than one third of the cases. All 90 cases were subclassified into etiologic categories with chromosomal 35, idiopathic 15, syndromic 11, cardiovascular 9, inborn errors of metabolism 6, lymphatic dysplasia 3, thoracic 3, infections 3, gastrointestinal 3 and hematologic 2. The NGS panel was used in 4 cases and 4 diagnoses were made.

CONCLUSIONS

In 90 cases with NIHF we identified an aneuploidy in more than one third of the cases. Improved techniques, such as possibly specific genetic analysis, could reduce the high rate of unexplained cases of NIHF.

EPHB4 Mutation Suppresses PROX1 Expression and Disrupts Lymphatic Development in Neonatal Hydrops

This case report highlights the importance of screening for mutations in EPHB4 and other genes that regulate lymphatic development in infants with the nonimmune hydrops fetalis.

Frequency and Prognosis of Hydrops Fetalis: A 10-Year Single-Center Experience

Objective:

The study aims to evaluate the etiological distribution and prognosis of newborn infants with hydrops fetalis (HF).

Methods:

All infants born in our hospital within the past 10 years and hospitalized with the diagnosis of HF were included in this retrospective descriptive study. Demographic characteristics, etiological distributions, treatment interventions, and prognosis information of the infants were recorded retrospectively. Infants with incomplete data were excluded from the study.

Results:

The mean gestational age of infants with HF was 33.6±3.1 weeks, and the mean birth weight was 2444±792 grams. Of the HF cases, 90.5% were born by cesarean section and the prenatal diagnosis rate was 42.9%. About 57.1% of the infants were intubated during resuscitation at birth in the delivery room. In the NICU, 81% of the cases were intubated and 71.4% received surfactant treatment. The most common HF findings were ascites (81%) and subcutaneous edema (81%). The most common interventional procedures were paracentesis (81%) and thoracentesis (52.4%). Exchange transfusion was performed in 2 cases (9.5%) due to immune HF. The mortality rate in the study group was 52.4%. Considering the etiological distribution of HF cases in the study group, three cases were diagnosed with immune HF (14.3%) and 18 cases with non-immune hydrops fetalis (NIHF) (85.7%). The underlying cause in immune HF cases was rhesus incompatibility. In cases with NIHF, idiopathic (23.8%) and cardiovascular diseases were the most common etiologies. A significant relationship was found between delivery room management and mortality. While the need for intubation in delivery room was significantly higher in non-survivors, the frequency of applying only positive pressure ventilation in the delivery room was significantly higher in survivors. While the rate of survival was 66.7% in immune HF cases, it was 44.4% in NIHF cases.

Conclusion:

The risk of perinatal mortality in infants with HF is high depending on the underlying cause. In this study, it was determined that HF mostly developed for non-immune reasons, prenatal diagnosis and follow-up were insufficient and the interventions performed in the delivery room were an important factor in predicting mortality in the follow-up of neonates with HF.

Utility of fetal whole exome sequencing in the etiological evaluation and outcome of nonimmune hydrops fetalis

INTRODUCTION

Nonimmune hydrops fetalis (NIHF) has varied etiology. We assessed the etiological spectrum and evaluated the utility of fetal whole exome sequencing (fWES) for the diagnosis of NIHF.

METHODS

In this prospective cohort study, we evaluated antenatally diagnosed fetuses with NIHF between July 2018 and December 2019 according to the routine diagnostic algorithm. Fetuses that remained undiagnosed after routine NIHF workup were subjected to fetal chromosomal microarray and/or WES. Pregnancies were followed up for clinical outcomes.

RESULTS

Of the 45 fetuses, consanguinity and recurrent hydrops fetalis were observed in 13.3% (6/45) and 28.8% (13/45), respectively. Overall, an etiological diagnosis was possible in 75.5% (34/45) of fetuses, while the cause remained unknown in 24.4% (11/45). A genetic etiology was identified in 46.6% (21/45): aneuploidy and monogenic disorders in 28.8% (13/45) and 17.8% (8/45), respectively. fWES on 19 fetuses detected disease-causing variants in 42.1% (8/19). Nine novel variants were detected in RAPSN, ASCC1, NEB, PKD1L1, GUSB, and PIEZO1. Only 8.8% (4/45) of the cohort survived without morbidity.

CONCLUSIONS

This study describes the etiological spectrum and the disease-causing variants in an Indian cohort of hydropic fetuses.

Prenatal delineation of a distinct lethal fetal syndrome caused by a homozygous truncating KIDINS220 variant

Kinase D-interacting substrate of 220 kDa (KIDINS220) is a transmembrane protein playing integral role in growth mediating pathways in the nervous and cardiovascular systems. KIDINS220 heterozygous truncating variants that affect the protein's C-terminus have been associated with a phenotype, so far described only in few unrelated children, including spastic paraplegia, intellectual disability, nystagmus, and obesity. More recently, a homozygous, more N-terminal truncating variant in KIDINS220 gene was suggested to be associated with enlarged cerebral ventricles and limb contractures in three fetuses from a consanguineous family. We confirm the latter finding by presenting the first detailed prenatal identification of a fetal phenotype associated with novel homozygous deleterious frameshift variant in KIDINS220 gene in a consanguineous healthy Egyptian couple. History of unexplained seven miscarriages and a similar stillbirth were recorded. Prenatal ultrasonography revealed limb contractions and ventriculomegaly; in addition to previously unreported cerebellar anomalies, cardiac anomalies and hydrops fetalis. These findings represent an expansion of clinical and molecular spectrum associated with KIDINS220 variants and broaden our understanding of genotype-phenotype relationships in lethal congenital contractures syndromes and associated severe abnormal embryological development. More generally, our study adds KIDINS220 to the rare group of genes which may cause disease by either of two distinct mutational mechanisms.

Nonimmune Hydrops Fetalis-Prenatal Diagnosis, Genetic Investigation, Outcomes and Literature Review

The aim of this paper is to review the outcomes and discuss the genetic and non-genetic aetiology of nonimmune hydrops fetalis in order to support differential ultrasound and genetic evaluations and family counselling. This single-centre study includes all cases of nonimmune hydrops fetalis diagnosed prenatally from 2009 to 2019. Two sources of data were used for this study (prenatal and neonatal) to compare and summarise the findings. Data from genetic testing and ultrasound scans were collected. In total, 33 pregnant women with prenatally diagnosed nonimmune hydrops fetalis were studied. The data included 30 cases of singleton (91%) and three cases (9%) of twin pregnancies. There were 14 survivors (43%), seven cases of postnatal deaths (21%), four cases of intrauterine foetal demises (12%), four cases of termination of pregnancy (12%), and four women without a follow up (12%). The total number of chromosomally normal singleton pregnancies was 29 (88%), and 14 foetuses had an anatomical abnormality detected on the ultrasound scan. The chance of survival was the highest in cases of isolated, idiopathic hydrops fetalis, which in most cases was due to an undetectable intrauterine infection. In many cases, the diagnosis could not be established throughout pregnancy. Each case of nonimmune hydrops fetalis should thus be analysed individually.

Utility of chromosomal microarray for diagnosis in cases of nonimmune hydrops fetalis

PURPOSE

Chromosomal microarray (CMA) is recommended in the diagnostic evaluation of cases with fetal structural anomalies when invasive testing is pursued. However, the utility of CMA for nonimmune hydrops fetalis (NIHF) specifically is not well known. Our objective was to describe the overall yield of CMA in the diagnostic evaluation of NIHF, comparing isolated cases to those with concurrent structural anomalies.

METHODS

This was a retrospective cohort study of all prenatally diagnosed NIHF cases evaluated at the University of California, San Francisco from 2008 to 2018. NIHF due to twin-twin transfusion syndrome was excluded.

RESULTS

There were 131 cases of prenatally diagnosed NIHF. In 43/44 cases with a CMA performed, results were categorized as normal or likely benign. One case was found on CMA to have a large pathogenic duplication of 21p11.2q22.3, which could have been detected by karyotype and was consistent with a diagnosis of Down syndrome. There was no incremental yield demonstrated for CMA over karyotype.

CONCLUSIONS

Among a cohort of prenatally diagnosed NIHF cases, CMA did not identify any copy number variants beyond those detectable by karyotype, and the vast majority of CMAs were normal. These results suggest that CMA has low diagnostic utility for NIHF.

Outcomes following antenatal identification of hydrops fetalis: a single-centre experience from 2001 to 2012

OBJECTIVE

To describe the aetiologies and outcomes of pregnancies complicated by hydrops fetalis (HF).

STUDY DESIGN

Case series of all pregnancies complicated by HF managed at The Royal Women's Hospital (RWH), Melbourne, Australia, between 2001 and 2012. Multiple pregnancies, and cases where antenatal care was not provided at RWH were excluded. Cases were identified from neonatal and obstetric databases. Data were extracted from maternal and neonatal case files, electronic pathology and radiology reports, and obstetric and neonatal databases.

RESULTS

Over 12 years, 131 fetuses with HF with a median (IQR) gestational age (GA) at diagnosis of 24 (20-30) weeks were included in the analysis. There were 65 liveborn infants with a median (IQR) GA at birth of 33 (31-37) weeks and a median (IQR) birthweight Z-score of 1.4 (0.4-2.2). Overall survival from diagnosis was 27% (36/131) increasing to 55% (36/65) if born alive.

CONCLUSIONS

The perinatal mortality risk for fetuses and newborn infants with HF is high with important differences dependent on underlying diagnosis and the time at which counselling is provided. Clinicians need to be aware of the outcomes of both fetuses and neonates with this condition.