Prenatal diagnosis and outcomes in fetuses with duplex kidney.

OBJECTIVE: Duplex kidney is a relatively frequent form of urinary system abnormality. This study aimed to elucidate the value of chromosomal microarray analysis (CMA) and whole exome sequencing (WES) for duplex kidney and the perinatal outcomes of duplex kidney fetuses. METHODS: This retrospective cohort study included 63 patients with duplex kidney diagnosed using antenatal ultrasound between August 2013 and January 2023. We reviewed the clinical characteristics, genetic test results, and pregnancy outcomes of the patients. RESULTS: Among the 63 cases based on the inclusion criteria, the CMA detected seven (11.1%) clinically significant variants and nine variants of uncertain significance (VUS), and the pathogenic/likely pathogenic (P/LP) copy number variations (CNVs) in the recurrent region that were associated with prenatal duplex kidney included 17q12, 17p13.3, and 22q11.2. No significant disparity was observed in the CMA detection rate between the unilateral and bilateral groups, or between the isolated and non-isolated groups. WES identified three (50%) P/LP single-gene variants in six fetuses with duplex kidney. We detected the following pathogenic genes in the duplex kidney fetuses: KMT2D, SMPD4, and FANCI. Pregnancy termination in cases where clinically significant variants were detected by genetic testing was different in statistical significance from that in cases with negative results (9/10, 90.0% vs 8/48, 16.7%, P < 0.001). CONCLUSION: This study elucidated the value of CMA and WES for fetal duplex kidney, proving that CMA and WES may be useful tools in prenatal diagnosis and genetic counseling.

Association of prenatal thoracic ultrasound abnormalities with copy number variants at a single Chinese tertiary center.

OBJECTIVE: To systematically evaluate the association of prenatal thoracic ultrasound abnormalities with copy number variants (CNVs). METHODS: Chromosomal microarray (CMA) data and clinical characteristics from fetuses with thoracic ultrasound abnormalities were retrieved and analyzed. RESULTS: Thoracic ultrasound findings were mainly isolated except for fetal pleural effusion (FPE) and pulmonary hypoplasia. The diagnostic yield of CMA for thoracic anomaly was 9.66%, and FPE (17/68, 25%), pulmonary hypoplasia (1/8, 12.5%), and congenital diaphragmatic hernia (CDH) (6/79, 7.59%) indicated relatively high pathogenic/likely pathogenic (P/LP) CNV findings. The detection rate for P/LP CNVs was obviously increased in non-isolated thoracic anomalies (27.91% vs. 1.96%, P < 0.0001), non-isolated FPE (37.78% vs. 0%, P = 0.0007) and non-isolated congenital pulmonary airway malformation (CPAM) (27.27% vs. 0%, P < 0.0001), and significantly different among thoracic anomalies. Additionally, the rate of termination of pregnancy in cases with non-isolated thoracic anomalies (58.49% vs. 12.34%, P < 0.0001) and P/LP CNVs (85.71% vs. 24.15%, P < 0.0001) was obviously increased. CONCLUSION: The present study expanded phenotype spectrums for particular recurrent CNVs. FPE, CDH, and pulmonary hypoplasia indicated relatively high P/LP CNV findings among common thoracic ultrasound abnormalities, CPAM associated with other ultrasound abnormalities increased the incidence of diagnostic CNVs, while bronchopulmonary sequestration might not be associated with positive CNVs. The present data recommended CMA application for cases with prenatal thoracic ultrasound abnormalities, especially non-isolated FPE, non-isolated CPAM, CDH, and pulmonary hypoplasia.

Prenatal diagnosis of polycystic renal diseases: diagnostic yield, novel disease-causing variants, and genotype-phenotype correlations.

BACKGROUND: Polycystic renal disease is a frequent congenital anomaly of the kidneys, but research using chromosomal microarray analysis and exome sequencing in fetuses with polycystic renal disease remains sparse, with most studies focusing on the multisystem or genitourinary system. OBJECTIVE: This study aimed to assess the detection rate of detectable genetic causes of fetal polycystic renal disease at different levels, novel disease-causing variants, and genotype-phenotype correlations. STUDY DESIGN: This study included 220 fetal polycystic renal disease cases from January 2014 to June 2022. Cases were divided into the following 3 groups: isolated multicystic dysplastic kidneys, nonisolated multicystic dysplastic kidneys, and suspected polycystic kidney disease group. We reviewed data on maternal demographics, ultrasonographic results, chromosomal microarray analysis/exome sequencing results, and pregnancy outcomes. RESULTS: In our cohort, chromosomal microarray analysis identified 19 (8.6%) fetuses carrying chromosomal abnormalities, and the most common copy number variation was 17q12 microdeletion (7/220; 3.2%). Furthermore, 94 families chose to perform trio-exome sequencing testing, and 21 fetuses (22.3%) were found to harbor pathogenic/likely pathogenic variants. There was a significant difference in the live birth rate among the 3 groups (91/130 vs 46/80 vs 1/10; P<.001). Among 138 live birth cases, 106 (78.5%) underwent postnatal ultrasound review, of which 95 (89.6%) had a consistent prenatal-postnatal ultrasound diagnosis. CONCLUSION: For both isolated and nonisolated polycystic renal disease, our data showed high detection efficiency with both testing tools. The detection of novel pathogenic variants expands the known disease spectrum of polycystic renal disease-associated genes while enriching our understanding of the genotype-phenotype correlation. Therefore, we consider it feasible to perform chromosomal microarray analysis+exome sequencing testing in fetal polycystic renal disease. Moreover, prenatal-postnatal ultrasound concordance was greater, the live birth rate was higher, and prognosis was better when known genetic disorders were excluded, indicating that genetic testing results significantly influenced pregnancy decisions.

PDIA2 variant associated with vitiligo.

The manuscript addresses an important topic: genetic analysis of Vitiligo. Vitiligo is a complicated condition and the genetic factors account for 80% of the risk. Linkage analysis for a four generations Chinese family identified 16p13.3p13.2 as the susceptibility locus of vitiligo, whole exome sequencing then identified PDIA2 as the new candidate gene. The association between the candidate gene and vitiligo requires further investigation.

A Deep-Learning-Based Method Can Detect Both Common and Rare Genetic Disorders in Fetal Ultrasound.

A global survey indicates that genetic syndromes affect approximately 8% of the population, but most genetic diagnoses can only be performed after babies are born. Abnormal facial characteristics have been identified in various genetic diseases; however, current facial identification technologies cannot be applied to prenatal diagnosis. We developed Pgds-ResNet, a fully automated prenatal screening algorithm based on deep neural networks, to detect high-risk fetuses affected by a variety of genetic diseases. In screening for Trisomy 21, Trisomy 18, Trisomy 13, and rare genetic diseases, Pgds-ResNet achieved sensitivities of 0.83, 0.92, 0.75, and 0.96, and specificities of 0.94, 0.93, 0.95, and 0.92, respectively. As shown in heatmaps, the abnormalities detected by Pgds-ResNet are consistent with clinical reports. In a comparative experiment, the performance of Pgds-ResNet is comparable to that of experienced sonographers. This fetal genetic screening technology offers an opportunity for early risk assessment and presents a non-invasive, affordable, and complementary method to identify high-risk fetuses affected by genetic diseases. Additionally, it has the capability to screen for certain rare genetic conditions, thereby enhancing the clinic's detection rate.

Fetal phenotype of Cornelia de Lange syndrome with a molecular confirmation.

OBJECTIVE: To present the fetal features of Cornelia de Lange Syndrome (CdLS) with a molecular confirmation. STUDY DESIGN: This was a retrospective study of 13 cases with CdLS diagnosed by prenatal and postnatal genetic testing and physical examination. Clinical and laboratory data were collected and reviewed for these cases, including maternal demographics, prenatal sonographic findings, chromosomal microarray and exome sequencing (ES) results, and pregnancy outcomes. RESULTS: All of the 13 cases were detected to have a CdLS-causing variant, with 8 variants identified in the NIPBL gene, 3 in SMC1A, and 2 in HDAC8. Five had normal ultrasound scans during pregnancy; all were caused by variants of SMC1A or HDAC8. For the eight cases with NIPBL variants, all had prenatal ultrasound markers. Three had first trimester ultrasound markers including increased nuchal translucency in one and limb defects in three. Four presented with normal ultrasound in the first trimester, but abnormal ultrasound in the second trimester, including micrognathia in two, hypospadias in one and intrauterine growth retardation (IUGR) in one. IUGR as the isolated feature was identified in one case in the third trimester. CONCLUSION: The prenatal diagnosis of CdLS caused by NIPBLvariants is possible. It seems to remain challenging to detect non-classic CdLS only relying on ultrasound examination.

Prenatal Diagnosis of Intragenic HNF1B Variant-Associated Renal Disease by Exome Sequencing.

Introduction: HNF1B-associated diseases are a group of genetic conditions that affect the kidney as well as other organ systems. Kidney anomalies are the most common symptoms. Other defects may include early-onset diabetes, genital abnormalities, and abnormalities of pancreas and liver function. Renal involvement has emerged as the earliest finding in HNF1B disease, even in prenatal life, with the most common feature being hyperechogenic kidneys. Case Presentation: In this study, we present 3 fetuses with bilateral renal hyperechogenicity identified by ultrasound in the second trimester. No pathogenic copy number variations were revealed by amniocentesis with chromosomal microarray analysis (CMA). Heterozygous variants in HNF1B were detected in all 3 fetuses by further investigation with exome sequencing (ES). Two pregnancies were terminated, and one was continued to term. Discussion and Conclusion: Because of the known high frequency of HNF1B aberrations in fetal hyperechogenic kidneys, HNF1B screening should be an integral part of prenatal diagnosis for such fetuses. ES should be recommended following or concurrently with CMA for rapid prenatal detection. The ES results would improve the diagnostic yield and are beneficial in guiding counseling and management.

Prenatal diagnosis of ultrasound soft markers in a single medical center of mainland China.

BACKGROUND: There are a few studies on the chromosomal aberration of Ultrasound soft markers (USMs). The aim of this study was to determine the detection rate of clinically significant chromosomal abnormalities (CSCA) in fetuses with different USMs. METHODS: This study included fetuses with USMs who underwent invasive prenatal diagnosis for karyotype and/or chromosomal microarray (CMA) by categorizing into two groups: a single USM (SUSM) and multiple USMs (MUSMs). RESULTS: Of the 358 cases with USMs, CSCA occurred in 3.09% (8/259) and 8.08% (8/99) of the SUSM and MUSM groups, respectively (P < 0.05). Of 16 cases identified with CSCA, theoretically 68.75% (11/16) could be detected by karyotype, while 31.25% (5/16) could be recognized only by CMA. Among CSCA cases, the most frequent USM was an absent or hypoplastic nasal bone (62.5%, 10/16). In cases with negative karyotypes and/or CMA, follow-up results were available in 307 cases, including 292 term deliveries, 6 preterm deliveries, 8 terminations of pregnancy due to USMs, and 1 still birth. CONCLUSION: MUSMs increased the risk of chromosomal abnormalities. An absent or hypoplastic nasal bone was the most clinically significant marker either alone or in combination with other USMs. Most of SUSM had a good prognosis.

Ndufa4 Regulates the Proliferation and Apoptosis of Neurons via miR-145a-5p/Homer1/Ccnd2.

The Dandy-Walker malformation (DWM) is characterized by neuron dysregulation in embryonic development; however, the regulatory mechanisms associated with it are unclear. This study aimed to investigate the role of NADH dehydrogenase 1 alpha subcomplex 4 (NDUFA4) in regulating downstream signaling cascades and neuronal proliferation and apoptosis. Ndufa4 overexpression promoted the proliferation of neurons and inhibited their apoptosis in vitro, which underwent reverse regulation by the Ndufa4 short hairpin RNAs. Ndufa4-knockout (KO) mice showed abnormal histological alterations in the brain tissue, in addition to impaired spatial learning capacity and exploratory activity. Ndufa4 depletion altered the microRNA expressional profiles of the cerebellum: Ndufa4 inhibited miR-145a-5p expression both in the cerebellum and neurons. miR-145a-5p inhibited the proliferation of neurons and promoted their apoptosis. Ndufa4 promoted and miR-145a-5p inhibited the expression of human homer protein homolog 1 and cyclin D2 in neurons. Thus, Ndufa4 promotes the proliferation of neurons and inhibits their apoptosis by inhibiting miR-145a-5p, which directly targets and inhibits the untranslated regions of Homer1 and Ccnd2 expression.

Genetic Analysis and Sonography Characteristics in Fetus with SHOX Haploinsufficiency.

OBJECTIVE: SHOX haploinsufficiency have been commonly found in isolated short stature (ISS) and Léri-Weill dyschondrosteosis (LWD) patients. However, few publications have described the genetic analysis and clinical characteristics of fetuses with SHOX haploinsufficiency. METHODS: Chromosomal microarray (CMA) were applied in 14,051 fetuses and sequentially whole exome sequence (WES) in 1340 fetuses who underwent prenatal diagnosis during 2016-2021. The analysis and summary of molecular genetics, sonographic characteristics, and follow-up results were performed in fetuses with SHOX haploinsufficiency without other genetic etiologies. A comparison was made between three groups according to prenatal diagnostic indications. RESULTS: 8 (0.06%) fetuses of SHOX haploinsufficiency were all detected by CMA, of which 5 (62.5%) were detected with short long bones by ultrasound scan, and 4 were inherited from their previously undiagnosed parents. No pathogenic SHOX variants were found by WES. The detection rate of SHOX haploinsufficiency was obviously higher in the short long bone group (2.6%, 5/191) than the other abnormality group (0.03%, 1/3919) or no ultrasound abnormality group (0.02%, 2/9941). Three of the fetuses were liveborn with normal growth up to the age of four and four were terminated. CONCLUSION: The phenotype of fetuses with SHOX haploinsufficiency is highly varied. Over 1/3 of the cases exhibited no phenotype and nearly 2/3 with short long bones, in the absence of Madelung deformity during fetal development. SHOX haploinsufficiency should be considered in all antenatal presentations, especially in the case of isolated short long bones. CMA can provide effective detection.

Variant spectrum of F8 and F9 in hemophilia patients from southern China and 26 novel variants.

Hemophilia, an X-linked recessive disorder, is characterized by spontaneous or trauma-induced prolonged bleeding. It is classified as hemophilia A when caused by variants in the F8 gene, and hemophilia B when caused by F9 variants. Few studies have described hemophilia variants in the Chinese population. This study aimed to investigate the clinical and genetic profiles of 193 hemophilia patients from southern China. Utilizing Sanger sequencing, multiplex ligation-dependent probe amplification, gap detection, long-range PCR, and multiplex PCR, we identified both F8 and F9 gene variants. Pregnant women with a history of hemophilia A offspring underwent amniocentesis or villus sampling for the variant detection. Variants in F8 and F9 were pinpointed in 183 patients, with 26 being novel discoveries. Notably, genetic testing was absent in the initial evaluation of 133 out of 161 patients, leading to a protracted average definitive diagnosis timeline of 2 years. Remarkably, two hemophilia A cases with anticipated severe phenotypes due to protein-truncating variants presented with only moderate or mild clinical manifestations. Among the 40 fetuses tested, 34 were males, with 17 exhibiting hemizygous variants in the F8 gene. Our results contribute to the broader understanding of F8 and F9 variant spectrum and highlight the underuse of genetic analyses in southern China.

The Value of a Comprehensive Genomic Evaluation in Prenatal Diagnosis of Genetic Diseases: A Retrospective Study.

Currently, there are still many challenges in prenatal diagnosis, such as limited or uncertain fetal phenotyping, variant interpretation, and rapid turnaround times. The aim of this study was to illustrate the value of a comprehensive genomic evaluation in prenatal diagnosis. We retrospectively reviewed 20 fetuses with clinically significant copy number variants (CNVs) detected by chromosomal microarray analysis (CMA) and no further exome sequencing testing in our tertiary center between 2019 and 2020. The residual DNA from the prenatal cases was used for the parallel implementation of CNV sequencing (CNV-seq) and trio-based clinical exome sequencing (trio-CES). CMA revealed 26 clinically significant CNVs (18 deletions and eight duplications) in 20 fetuses, in which five fetuses had two or more CNVs. There were eight fetuses with pathogenic CNVs (e.g., del 1p36), nine fetuses with likely pathogenic CNVs (e.g., dup 22q11.21), and three fetuses with variants of unknown significance (VOUS, e.g., dup 1q21.1q21.2). Trio-CES identified four fetuses with likely pathogenic mutations (SNV/InDels). Of note, a fetus was detected with a maternally inherited hemizygous variant in the SLX4 gene due to a 16p13.3 deletion on the paternal chromosome. The sizes of CNVs detected by CNV-seq were slightly larger than that of the SNP array, and four cases with mosaic CNVs were all identified by CNV-seq. In conclusion, microdeletion/duplication syndromes and monogenic disorders may co-exist in a subject, and CNV deletion may contribute to uncovering additional recessive disease alleles. The application of a comprehensive genomic evaluation (CNVs and SNV/InDels) has great value in the prenatal diagnosis arena. CNV-seq based on NGS technology is a reliable and a cost-effective technique for identifying CNVs.

Sotos syndrome: A study of antenatal presentation.

OBJECTIVE: To determine the fetal ultrasound findings associated with Sotos syndrome caused by deletions at 5q35 including the NSD1 and a point mutation in this gene. STUDY DESIGN: This was a retrospective study of eight pregnancies with fetal Sotos syndrome identified by chromosomal microarray (CMA)/whole exome sequencing (WES). Clinical and laboratory data were collected and reviewed for these cases. RESULTS: Two cases had no significant fetal abnormalities, and were only diagnosed after birth. One case presented in the first trimester with increased nuchal translucency. The remaining five fetuses were identified at late gestation. One of the five fetuses presented in the second trimester with mild ventriculomegaly, and four in the third trimester with mild ventriculomegaly, macrocephaly and polyhydramnios. CMA was done on all cases and revealed 5q35 deletions in seven cases, and WES detected a maternally inherited NSD1 variant in one case. CONCLUSION: The fetal ultrasound findings in cases with Sotos syndrome, associated with deletions at 5q35 and a point mutation in the NSD1 are not specific with the most common finding being mild ventriculomegaly.

Application of exome sequencing for prenatal diagnosis of fetal structural anomalies: clinical experience and lessons learned from a cohort of 1618 fetuses.

BACKGROUND: Exome sequencing (ES) is becoming more widely available in prenatal diagnosis. However, data on its clinical utility and integration into clinical management remain limited in practice. Herein, we report our experience implementing prenatal ES (pES) in a large cohort of fetuses with anomalies detected by ultrasonography using a hospital-based in-house multidisciplinary team (MDT) facilitated by a three-step genotype-driven followed by phenotype-driven analysis framework. METHODS: We performed pES in 1618 fetal cases with positive ultrasound findings but negative for karyotyping and chromosome microarray analysis between January 2014 and October 2021, including both retrospective (n=565) and prospective (n=1053) cohorts. The diagnostic efficiency and its correlation to organ systems involved, phenotypic spectrum, and the clinical impacts of pES results on pregnancy outcomes were analyzed. RESULTS: A genotype-driven followed by phenotype-driven three-step approach was carried out in all trio pES. Step 1, a genotype-driven analysis resulted in a diagnostic rate of 11.6% (187/1618). Step 2, a phenotype-driven comprehensive analysis yielded additional diagnostic findings for another 28 cases (1.7%; 28/1618). In the final step 3, data reanalyses based on new phenotypes and/or clinical requests found molecular diagnosis in 14 additional cases (0.9%; 14/1618). Altogether, 229 fetal cases (14.2%) received a molecular diagnosis, with a higher positive rate in the retrospective than the prospective cohort (17.3% vs. 12.4%, p<0.01). The diagnostic rates were highest in fetuses with skeletal anomalies (30.4%) and multiple organ involvements (25.9%), and lowest in fetuses with chest anomalies (0%). In addition, incidental and secondary findings with childhood-onset disorders were detected in 11 (0.7%) cases. Furthermore, we described the prenatal phenotypes for the first time for 27 gene-associated conditions (20.0%, 27/135) upon a systematic analysis of the diagnosed cases and expanded the phenotype spectrum for 26 (19.3%) genes where limited fetal phenotypic information was available. In the prospective cohort, the combined prenatal ultrasound and pES results had significantly impacted the clinical decisions (61.5%, 648/1053). CONCLUSIONS: The genotype-driven approach could identify about 81.7% positive cases (11.6% of the total cohort) with the initial limited fetal phenotype information considered. The following two steps of phenotype-driven analysis and data reanalyses helped us find the causative variants in an additional 2.6% of the entire cohort (18.3% of all positive findings). Our extensive phenotype analysis on a large number of molecularly confirmed prenatal cases had greatly enriched our current knowledge on fetal phenotype-genotype correlation, which may guide more focused prenatal ultrasound in the future. This is by far the largest pES cohort study that combines a robust trio sequence data analysis, systematic phenotype-genotype correlation, and well-established MDT in a single prenatal clinical setting. This work underlines the value of pES as an essential component in prenatal diagnosis in guiding medical management and parental decision making.

Prenatal diagnosis of 21 fetuses with balanced chromosomal abnormalities (BCAs) using whole-genome sequencing.

Balanced chromosomal abnormalities (BCAs) are the most common chromosomal abnormalities and the frequency of congenital abnormalities is approximately twice as high in newborns with a de novo BCA, but a prenatal diagnosis based on BCAs is subject to evaluation. To detect translocation breakpoints and conduct a prenatal diagnosis, we performed whole-genome sequencing (WGS) in 21 subjects who were found BCAs, 19 balanced chromosome translocations and two inversions, in prenatal screening. In 16 BCAs on non-N-masked regions (non-NMRs), WGS detected 13 (81.2%, 13/16) BCAs, including all the inversions. All the breakpoints of 12 (12/14) cases of sufficient DNA were confirmed by Sanger sequencing. In 13 interrupted genes, CACNA1E (in case 12) and STARD7 (in case 17) are known causative and PDCL was found in subject (case 11) with situs inversus for the first time. Case 12 with abnormal ultrasound reached a definitive genetic diagnosis of CACNA1E-disease, while STARD7 exon deletion has never been found causative in patients. WGS provides the possibility of prenatal diagnosis in fetuses with BCAs, and its clinical significance also lies in providing data for postnatal diagnosis.

Prenatal Diagnosis of Talipes Equinovarus by Ultrasound and Chromosomal Microarray Analysis: A Chinese Single-Center Retrospective Study.

Background: There are few studies on the detection rate by chromosomal microarray analysis (CMA) of the prenatal diagnosis of talipes equinovarus (TE) compared to conventional karyotyping. We aimed to explore the molecular etiology of fetal TE and examine the detection rate by CMA, which provides more information for the clinical screening and genetic counseling of TE. Methods: In this retrospective study, pregnancies diagnosed with fetal TE were enrolled and clinical data for all cases were retrieved from our medical record database, including demographic data for pregnancies, ultrasound findings, karyotype/CMA results, and pregnant and perinatal outcomes. Results: Among the 164 patients, 17 (10.4%) clinically significant variants were detected by CMA. In 148 singleton pregnancies, the diagnostic rate of clinically significant variants was significantly higher in the non-isolated TE group than in the isolated TE group (10/37, 27.0% vs. 6/111, 5.4%, P < 0.001). In twin pregnancies, 1 (6.3%) pathogenic copy number variant was present in the other 16 twin pregnancies. Conclusions: This study demonstrates that CMA is useful for the prenatal genetic diagnosis of fetal TE. Fetal TE with the associated structural malformation correlates with a higher probability of clinically significant variants. This data may aid prenatal diagnosis and genetic counseling for fetal TE.

Prenatal Diagnosis and Outcomes in Fetuses with Hemivertebra.

Background: There are few studies on the burden of chromosomal abnormalities and single gene disorders in fetal hemivertebra (HV). We aim to investigate the cytogenetic and monogenic risk and evaluate prenatal outcomes of fetal HV. Method: This study included fetuses diagnosed with HV divided into two groups: isolated HV and non-isolated HV. Data on other sonographic structural anomalies, chromosomal and sub-chromosomal abnormalities, monogenic variations detected by WES, and prenatal outcomes are recorded and reviewed. Results: Among 109 fetal HV cases, forty-seven (43.1%) non-isolated HV cases were associated with structural anomalies. Chromosomal test results were available in 58 cases, identifying six (10.3%) chromosomal aberrations involved in four isolated and two non-isolated HV. WES identified four (likely) pathogenic variants in three cases among 16 fetuses with HV, involving three novel variants, 1250G > T and c.1277G> inherited from parents, respectively, in DLL3 and c.7213C > A ** in the FLNB. The live birth rate (LB) was higher in the isolated fetal HV group than in the non-isolated group (67.7% (42/62) vs. 12.5% (12/47), p < 0.001). Conclusion: This study emphasizes the risk of cytogenetic abnormalities in isolated HV. WES yields a diagnostic rate of 18.3% in HV with normal CMA, probably aiding the prenatal counseling and management of fetal HV.