Interstitial deletion of chromosome 1 (1p21.1p12) in an infant with congenital diaphragmatic hernia, hydrops fetalis, and interrupted aortic arch

Hydrops and congenital diaphragmatic hernia: reported incidence and postnatal outcomes. Analysis of the congenital diaphragmatic hernia study group registry

OBJECTIVE

Congenital Diaphragmatic Hernia (CDH) associated with hydrops is rare. The aim of this study was to describe the incidence of this combination of anomalies and the postnatal outcomes from a large database for CDH.

STUDY DESIGN

Data from the multicenter, multinational database on infants with prenatally diagnosed CDH (CDHSG Registry) born from 2015 to 2021 were analyzed.

RESULTS

A total of 3985 patients were entered in the registry during the study period, 3156 were prenatally diagnosed and 88 were reported to have associated fluid in at least 1 compartment, representing 2.8% of all prenatally diagnosed CDH cases in the registry. The overall survival to discharge for CDH patients with hydrops was 43%. The hydropic CDH group had lower birth weight and gestational age at birth, and increased incidence of right-sided CDH (55%), and rate of non-repair (45%). However, the survival rate for hydropic infants with CDH undergoing surgical repair was 80%. Other associated anomalies were more common in hydropic CDH (50% vs 37%, p = 0.001).

CONCLUSION

Hydropic CDH is rare, only 2.8% of all prenatally diagnosed cases, and more commonly occurring in right-sided CDH. Survival rates are low, with higher rates of non-repair. However, decision-making regarding goals of care and an aggressive surgical approach in selected cases may result in survival rates comparable to non-hydropic cases.

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.

A system-based approach to the genetic etiologies of non-immune hydrops fetalis

A wide spectrum of genetic causes may lead to nonimmune hydrops fetalis (NIHF), and a thorough phenotypic and genetic evaluation are essential to determine the underlying etiology, optimally manage these pregnancies, and inform discussions about anticipated prognosis. In this review, we outline the known genetic etiologies of NIHF by fetal organ system affected, and provide a systematic approach to the evaluation of NIHF. Some of the underlying genetic disorders are associated with characteristic phenotypic features that may be seen on prenatal ultrasound, such as hepatomegaly with lysosomal storage disorders, hyperechoic kidneys with congenital nephrosis, or pulmonary valve stenosis with RASopathies. However, this is not always the case, and the approach to evaluation must include prenatal ultrasound findings as well as genetic testing and many other factors. Genetic testing that has been utilized for NIHF ranges from standard chromosomal microarray or karyotype to gene panels and broad approaches such as whole exome sequencing. Family and obstetric history, as well as pathology examination, can yield additional clues that are helpful in establishing a diagnosis. A systematic approach to evaluation can guide a more targeted approach to genetic evaluation, diagnosis, and management of NIHF.