Targeted linked-read sequencing for direct haplotype phasing of parental GJB2/SLC26A4 alleles: A universal and dependable noninvasive prenatal diagnosis method applied to autosomal recessive nonsyndromic hearing loss in at-risk families.

Noninvasive prenatal diagnosis (NIPD) for autosomal recessive nonsyndromic hearing loss (ARNSHL) has been rarely reported until recent years. However, the previous method could not be performed on challenging genome loci (e.g. CNVs, deletions, inversions, or gene recombinants) or on families without proband genotype. Here, this study assesses the performance of relative haplotype dosage analysis (RHDO)-based NIPD for identifying fetal genotyping in pregnancies at risk of ARNSHL. Fifty couples carrying pathogenic variants associated with ARNSHL in either GJB2 or SLC26A4 were recruited. The RHDO-based targeted linked-read sequencing combined with whole gene coverage probes was used to genotype the fetal cell-free DNA (cfDNA) of 49 families that met the quality control standard.. Fetal amniocyte samples were genotyped using invasive prenatal diagnosis (IPD) to assess the performance of NIPD. The NIPD results showed 100%(49/49) concordance with those obtained through IPD. Two families with copy number variation and recombination were also successfully identified. Sufficient specific informative SNPs for haplotyping, as well as the fetal cfDNA concentration and sequencing depth, are prerequisites for RHDO-based NIPD. This method has the merits of covering the entire genes of GJB2 and SLC26A4, qualifying for copy number variation and recombination analysis with remarkable sensitivity and specificity. Therefore, it has clinical potential as an alternative to traditional IPD for ARNSHL.

Prenatal Diagnosis and Outcomes of Cervical Meningocele and Myelomeningocele.

Prenatal diagnosis of myelomeningocele remains challenging for obstetricians, ultrasonographers, and radiologists, although the increased maternal serum alpha-fetoprotein level aids in the confirmative diagnosis. Fetal cervical myelomeningocele and meningocele are very rare and unique types of myelomeningocele. Prenatal diagnosis of cervical myelomeningocele and meningocele should include the differential diagnosis and association of many intracranial and spino-skeletal pathogenetic variants and genetic diseases, including subependymal nodular heterotopia and Klippel-Feil syndrome. In this report, a comprehensive review of fetal cervical myelomeningocele with its prenatal diagnosis and long-term outcomes is presented.

Prenatal Diagnosis of Oral Teratoma by Ultrasound.

A pregnant woman had a normal second-trimester anatomic survey at 22 weeks gestation. She was revealed to have a fetal oral mass with polyhydramnios and invisible stomach bubble by ultrasound at 28 weeks. A 50 mm × 36 mm × 42 mm, solid mass was found in the fetal mouth, filling the entire oral cavity. Fetal magnetic resonance imaging showed a homogeneous solid mass in the oral cavity compressing the hypopharynx. At 33 weeks, preterm labor occurred because of the continuation of increased amniotic fluid volume, and a female infant was vaginally delivered. The infant died shortly after tracheal intubation attempt failed. Autopsy confirmed the prenatal sonographic finding. The final pathologic diagnosis was oral immature teratoma. Our study indicates that although oral teratomas are rare, they are readily apparent at prenatal sonographic examinations. Respiratory compromise is the frequent complication of oral teratomas, which is associated with high perinatal mortality.

Time to initiation of antenatal care and its predictors among pregnant women in Ethiopia: a multilevel mixed-effects acceleration failure time model.

OBJECTIVE: To assess the time to initiation of antenatal care (ANC) and its predictors among pregnant women in Ethiopia. DESIGN: Retrospective follow-up study using secondary data from the 2019 Ethiopian Mini-Demographic and Health Survey. SETTING AND PARTICIPANTS: 2933 women aged 15-49 years who had ANC visits during their current or most recent pregnancy within the 5 years prior to the survey were included in this study. Women who attended prenatal appointments but whose gestational age was unknown at the first prenatal visit were excluded from the study. OUTCOME MEASURES: Participants were interviewed about the gestational age in months at which they made the first ANC visit. Multivariable mixed-effects survival regression was fitted to identify factors associated with the time to initiation of ANC. RESULTS: In this study, the estimated mean survival time of pregnant women to initiate the first ANC visit in Ethiopia was found to be 6.8 months (95% CI: 6.68, 6.95). Women whose last birth was a caesarean section (adjusted acceleration factor (AAF)=0.75; 95% CI: 0.61, 0.93) and women with higher education (AAF)=0.69; 95% CI: 0.50, 0.95) had a shorter time to initiate ANC early in the first trimester of pregnancy. However, being grand multiparous (AAF=1.31; 95% CI: 1.05, 1.63), being previously in a union (AAF=1.47; 95% CI: 1.07, 2.00), having a home birth (AAF=1.35; 95% CI: 1.13, 1.61) and living in a rural area (AAF=1.25; 95% CI: 1.03, 1.52) were the impediments to early ANC initiation. CONCLUSION: Women in this study area sought their initial ANC far later than what the WHO recommended. Therefore, healthcare providers should collaborate with community health workers to provide home-based care in order to encourage prompt ANC among hard-to-reach populations, such as rural residents and those giving birth at home.

Noninvasive Prenatal Diagnosis of SEA-Thalassemia by Combining 1000 Genomes Database and Relative Haplotype Dosage.

To explore a noninvasive method for diagnosis of SEA-thalassemia and to investigate whether the regional factors affect the accuracy of this method. The method involved using a public database and bioinformatics software to construct parental haplotypes for proband and predicting fetal genotypes using relative haplotype dosage. We screened and downloaded sequencing data of couples who were both SEA-thalassemia carriers from the China National Genebank public data platform, and matched the sequencing data format with that of the reference panel using Ubuntu system tools. We then used Beagle software to construct parental haplotypes, predicted fetal haplotypes by relative haplotype dosage. Finally, we used Hidden Markov Model and Viterbi algorithm to determine fetal pathogenic haplotypes. All noninvasive fetal genotype diagnosis results were compared with gold standard gap-PCR electrophoresis results. Our method was successful in diagnosing 13 families with SEA-thalassemia carriers. The best diagnostic results were obtained when Southern Chinese Han was used as the reference panel, and 10 families showed full agreement between our noninvasive diagnostic results and the gap-PCR electrophoresis results. The accuracy of our method was higher when using a Chinese Han as the reference panel for haplotype construction in the Southern Chinese Han region as opposed to Beijing Chinese region. The combined use of public databases and relative haplotype dosage for diagnosing SEA-thalassemia is a feasible approach. Our method produces the best noninvasive diagnostic results when the test samples and population reference panel are closely matched in both ethnicity and geography. When constructing parental haplotypes with our method, it is important to consider the effect of region in addition to population background alone.

Noninvasive prenatal testing for the detection of fetal chromosome 17 microduplication: clinical implications and findings.

BACKGROUND:  Noninvasive prenatal testing (NIPT) is widely used to screen for fetal aneuploidies. However, there are few reports of using NIPT for screening chromosomal microduplications and microdeletions. This study aimed to investigate the application efficiency of NIPT for detecting chromosomal microduplications. METHODS: Four cases of copy number gains on the long arm of chromosome 17 (17q12) were detected using NIPT and further confirmed using copy number variation (CNV) analysis based on chromosome microarray analysis (CMA). RESULTS: The prenatal diagnosis CMA results of the three cases showed that the microduplications in 17q12 (ranging from 1.5 to 1.9 Mb) were consistent with the NIPT results. The karyotypic analysis excluded other possible unbalanced rearrangements. The positive predictive value of NIPT for detecting chromosomal 17q12 microduplication was 75.0%. CONCLUSIONS:  NIPT has a good screening effect on 17q12 syndrome through prenatal diagnosis, therefore it could be considered for screening fetal CNV during the second trimester. With the clinical application of NIPT, invasive prenatal diagnoses could be effectively reduced while also improving the detection rate of fetal CNV.

From phenotype to mechanism: Prenatal spectrum of NKAP mutation-related disorder and its pathogenesis inducing congenital heart disease.

NKAP mutations are associated with Hackmann-Di Donato-type X-linked syndromic intellectual developmental disorder (MRXSHD, MIM: #301039). Here, we elucidate the potential prenatal manifestation of NKAP mutation-associated disorder for the first time, alongside revealing the relationship between NKAP mutations and congenital heart defect (CHD) in the Chinese population. An NKAP mutation (NM_024528.4: c.988C>T, p.Arg330Cys) was identified in two foetuses presenting with CHD. Subsequent mechanistic exploration revealed a marked downregulation of NKAP transcription within HEK293T cells transfected with NKAP p.R330C. However, no significant change was observed at the protein level. Moreover, the mutation led to a dysregulation in the transcription of genes associated with cardiac morphogenesis, such as DHRS3, DNAH11 and JAG1. Additionally, our research determined that NKAP p.R330C affected Nkap protein intra-nuclear distribution, and binding with Hdac3. Summarily, our study strengthens NKAP mutations as a cause of CHD and prompts the reclassification of NKAP p.R330C as likely pathogenic, thereby establishing a prospective prenatal phenotypic spectrum that provides new insight into the prenatal diagnosis of CHD. Our findings also provide evidence of NKAP p.R330C pathogenicity and demonstrate the potential mechanism by which p.R330C dysregulates cardiac developmental gene transcription by altering Nkap intra-nuclear distribution and obstructing the interaction between Nkap and Hdac3, thereby leading to CHD.

Prenatal Diagnosis by Trio Clinical Exome Sequencing: Single Center Experience.

Fetal anomalies, characterized by structural or functional abnormalities occurring during intrauterine life, pose a significant medical challenge, with a notable prevalence, affecting approximately 2-3% of live births and 20% of spontaneous miscarriages. This study aims to identify the genetic cause of ultrasound anomalies through clinical exome sequencing (CES) analysis. The focus is on utilizing CES analysis in a trio setting, involving the fetuses and both parents. To achieve this objective, prenatal trio clinical exome sequencing was conducted in 51 fetuseses exhibiting ultrasound anomalies with previously negative results from chromosomal microarray (CMA) analysis. The study revealed pathogenic variants in 24% of the analyzed cases (12 out of 51). It is worth noting that the findings include de novo variants in 50% of cases and the transmission of causative variants from asymptomatic parents in 50% of cases. Trio clinical exome sequencing stands out as a crucial tool in advancing prenatal diagnostics, surpassing the effectiveness of relying solely on chromosomal microarray analysis. This underscores its potential to become a routine diagnostic standard in prenatal care, particularly for cases involving ultrasound anomalies.

Prenatal Diagnosis and Prognosis of Abdominal Arteriovenous Fistulae: A Comprehensive Case Series and Systematic Review.

This study had two main objectives. Firstly, we conducted a thorough literature review on the prenatal diagnosis of abdominal congenital arteriovenous fistulas (CAVFs) involving the abdominal aorta and hepatic arteries. Secondly, we aimed to provide detailed descriptions of eight additional cases diagnosed at our medical center and assess the outcome of this anomaly for informed counseling. We conducted a systematic search of online databases using specific keywords like "outcome", "ultrasound", "intrahepatic fistulae", and "fetal venous anomalies", focusing on studies published between 1998 and 2023. We selected 10 relevant articles and analyzed 13 cases. Additionally, we conducted a five-year prospective study in two referral centers, identifying eight CAVF cases with an incidence rate of 0.16%. Among the 21 cases evaluated, 11 resulted in live births, all of which received treatment. However, four cases (36.3%) had poor postnatal outcomes and neonatal demise due to heart failure. Prenatal signs of poor fetal hemodynamics, including cardiomegaly or hydrops, were observed in 52.3% of cases, regardless of outcome. Our findings highlight the rarity of this vascular malformation and emphasize the importance of effective treatment to avoid unfavorable outcomes. The long-term effectiveness of prenatal treatment or postnatal embolization remains uncertain, with liver transplantation being considered the most reliable treatment option.

OIES complex diagnosed by in utero ultrasound a case report.

INTRODUCTION AND IMPORTANCE: OEIS complex is a rare and complex anomaly of the genitourinary and intestinal tract. It includes Omphalocele, Exstrophy of cloaca, Imperforate anus and Spinal defects. PRESENTATION OF CASE: We are reporting a case of OEIS complex. CLINICAL DISCUSSION: Cloacal exstrophy is considered the most severe ventral abdominal wall defect. Diagnosis is primarily antenatal based on the presenting features on ultrasonography. Management requires initial resuscitation and stabilization followed by either single staged closure or multistage procedures by multi-disciplinary surgical team. CONCLUSION: The introduction of better diagnostic techniques and the detection of fetal malformations during pregnancy is it's the cornerstone of care.

Fetal Wilm's tumor detection preceding the development of isolated lateralized overgrowth of the limb: a case report and review of literature.

Fetal Wilms tumor (WT) is extremely rare, but with advances in fetal imaging, more cases are being reported. The management of these cases remains challenging. Herein, we present the case of a full-term female infant diagnosed antenatally at 32 weeks of gestation with a right solid renal mass detected on routine prenatal ultrasound without polyhydramnios. At birth, the infant was healthy, with no evidence of dysmorphic features or abnormal laboratory tests to suggest a predisposition syndrome. Her family history was also unremarkable. A successful radical right nephrectomy was performed on day 2 of life revealing a classic WT. She received vincristine as adjuvant chemotherapy without any complications. At the age of 1 month, the infant developed isolated lateralized overgrowth of the right lower limb suspicious of Beckwith-Wiedemann syndrome. At the latest follow-up of 4 years, the child is healthy and disease-free with conserved asymmetry of lower limbs. The case provides insights into the challenging diagnosis and treatment of fetal WT. A review of the literature suggests that the presence of polyhydramnios is a worse prognostic factor while the combination of best supportive care and surgery remains the best management. Fetal WT can be associated with predisposition syndromes; however, their first manifestations can develop after the diagnosis of cancer has been made, as in our patient. We propose starting active surveillance programs and genetic testing for any case of fetal WT.

Clinical application value of pre-pregnancy carrier screening in Chinese Han childbearing population.

BACKGROUND: To explore the clinical application value of pre-conception expanded carrier screening (PECS) in the Chinese Han ethnicity population of childbearing age. METHODS: The results of genetic testing of infertile parents who underwent PECS in the Reproductive Medicine Center of the Second Affiliated Hospital of Zhengzhou University, China, from September 2019 to December 2021, were retrospectively analyzed. The carrier rate of single gene disease, the detection rate of high-risk parents, and the clinical outcome of high-risk parents were statistically analyzed. RESULTS: A total of 1372 Chinese Han ethnicity patients underwent PECS, among which 458 patients underwent the extended 108-gene test, their overall carrier rate was 31.7%, and the detection rate of high-risk parents was 0.3%. The highest carrier rates were SLC22A (2.4%), ATP7B (2.4%), MMACHC (2.2%), PAH (1.8%), GALC (1.8%), MLC1 (1.3%), UNC13D (1.1%), CAPN3 (1.1%), and PKHD1 (1.1%). There were 488 women with fragile X syndrome-FMR1 gene detection, and 6 patients (1.2%) had FMR1 gene mutation. A total of 426 patients were screened for spinal muscular atrophy-SMN1, and the carrier rate was 3.5%, and the detection rate of parents' co-carrier was 0.5%. CONCLUSION: Monogenic recessive hereditary diseases had a high carrier rate in the population. Pre-pregnancy screening could provide good prenatal and postnatal care guidance for patients and preimplantation genetic testing for monogenic/single gene disorders (PGT-M) and prenatal diagnosis could provide more precise reproductive choices for high-risk parents.

Estimating fetal weight in gastroschisis: A 10 year audit of outcomes at the National Maternity Hospital.

OBJECTIVE: To identify whether conventional methods of estimating fetal growth (Hadlock's formula), which relies heavily on abdominal circumference measurements, are accurate in fetuses with gastroschisis. METHODS: A retrospective cohort study was performed between the period January 1, 2011 and December 31, 2021 in a tertiary referral maternity hospital identifying all pregnancies with a diagnosis of gastroschisis. Projected fetal weight was obtained using the formula (EFW [Hadlock's formula] + 185 g × [X/7]) where X was the number of days to delivery. RESULTS: During the study period 41 cases were identified. The median maternal age was 25. The median BMI was 25 and 63% were primiparous women (n = 26). Median gestation at diagnosis was 21 weeks. Median gestation at delivery was 36 weeks. A total of 4.8% of mothers had a history of drug use (n = 2). The rate of maternal tobacco use was 21.9% (n = 9). A total of 4.8% of fetuses had additional congenital anomalies including amniotic band syndrome and myelomeningocele (n = 2). Estimated fetal weight (EFW) and birth weight data were available for 34 cases. A Wilcoxon signed-rank test showed projected EFW using Hadlock's formula did not result in a statistically significant different birth weight (Z = -1.3, P = 0.169). Median projected weight and actual birth weight were 2241.35 and 2415 g respectively. Median difference was 0.64 g (95% CI: -148 to -28.5). CONCLUSION: Our data showed accuracy using standard formulae for EFW in fetuses with gastroschisis.

Extending the new era of genomic testing into pregnancy management: A proposed model for Australian prenatal services.

BACKGROUND: Trio exome sequencing can be used to investigate congenital abnormalities identified on pregnancy ultrasound, but its use in an Australian context has not been assessed. AIMS: Assess clinical outcomes and changes in management after expedited genomic testing in the prenatal period to guide the development of a model for widespread implementation. MATERIALS AND METHODS: Forty-three prospective referrals for whole exome sequencing, including 40 trios (parents and pregnancy), two singletons and one duo were assessed in a tertiary hospital setting with access to a state-wide pathology laboratory. Diagnostic yield, turn-around time (TAT), gestational age at reporting, pregnancy outcome, change in management and future pregnancy status were assessed for each family. RESULTS: A clinically significant genomic diagnosis was made in 15/43 pregnancies (35%), with an average TAT of 12 days. Gestational age at time of report ranged from 16 + 5 to 31 + 6 weeks (median 21 + 3 weeks). Molecular diagnoses included neuromuscular and skeletal disorders, RASopathies and a range of other rare Mendelian disorders. The majority of families actively used the results in pregnancy decision making as well as in management of future pregnancies. CONCLUSIONS: Rapid second trimester prenatal genomic testing can be successfully delivered to investigate structural abnormalities in pregnancy, providing crucial guidance for current and future pregnancy management. The time-sensitive nature of this testing requires close laboratory and clinical collaboration to ensure appropriate referral and result communication. We found the establishment of a prenatal coordinator role and dedicated reporting team to be important facilitators. We propose this as a model for genomic testing in other prenatal services.

Prenatal Ultrasound Diagnosis of Vasa Previa With Careful Intraoperative Management: A Case Report.

Vasa previa is a rare but potentially life-threatening condition to the fetus. Timely antenatal diagnosis and delivery by cesarean section (CS) can lead to a favorable outcome. Here, we report a case of recurrent pregnancy loss (G3A2) with vasa previa, which was diagnosed prenatally by ultrasound. She was admitted at her 31st week with bleeding per vaginum (PV) provisionally diagnosed as antepartum hemorrhage (APH) and managed conservatively as placenta previa. Follow-up ultrasonography (USG) revealed vasa previa at 33 weeks. The fetus was delivered by lower segment cesarean section (LSCS) after careful separation of the membranes and avoiding damage to the vessels as there was velamentous insertion of cord with the lower margin of the placenta in the lower segment. The baby was cared for in the neonatal intensive care unit due to prematurity and discharged after six days. This case report highlights the importance of prenatal ultrasound in diagnosing vasa previa and planning an elective cesarean section with caution intraoperatively for the safe delivery of the baby.

Clinical manifestations and the prenatal diagnosis of trisomy 7 mosaicism: Two case reports.

BACKGROUND: The clinical manifestations of trisomy 7 mosaicism are diverse and nonspecific, so prenatal diagnosis is very difficult. CASE SUMMARY: Two pregnant women with abnormal prenatal screening results were included. One was a 22-year-old woman (G1P0). At 31st week of gestation, ultrasound revealed that the posterior horn of the left lateral ventricle was 10 mm and the right renal pelvis had a separation of 7 mm. The other pregnant woman was 33 years old (G2P1L1A0), and her fetus was found to have a cardiac malformation at the 24th week of gestation. Copy number variation sequencing, whole-exome sequencing and karyotype analysis were carried out after amniocentesis, and both fetuses were diagnosed with trisomy 7 mosaicism. After parental counseling, one woman continued the pregnancy, and the other woman terminated the pregnancy. CONCLUSION: In trisomy 7 mosaicism, the low proportion of trisomy does not lead to abortion, but can result in abnormal fetal development, which can be detected via ultrasound. Therefore, clinicians need to pay more attention to various aspects of fetal growth and development, combining with imaging, cellular, molecular genetics and other methods to perform comprehensive evaluations of fetuses to provide more reliable genetic counseling for pregnant women.

Disproportion of Corpus Callosum in Fetuses With Malformations of Cortical Development.

OBJECTIVE: To evaluate corpus callosum (CC) size in fetuses with malformations of cortical development (MCD) and to explore the diagnostic value of three CC length (CCL) ratios in identifying cortical abnormalities. METHODS: This is a single-center retrospective study in singleton fetuses at 20-37 weeks of gestation between April 2017 and August 2022. The midsagittal plane of the fetal brain was obtained and evaluated for the following variables: length, height, area of the corpus callosum, and relevant markers, including the ratios of corpus callosum length to internal cranial occipitofrontal dimension (CCL/ICOFD), corpus callosum length to femur length (CCL/FL), and corpus callosum length to cerebellar vermian diameter (CCL/VD). Intra-class correlation coefficient (ICC) was used to evaluate measurement consistency. The accuracy of biometric measurements in prediction of MCD was assessed using the area under the receiver-operating-characteristics curves (AUC). RESULTS: Fetuses with MCD had a significantly decreased CCL, height (genu and splenium), and area as compared with those of normal fetuses (P < .05), but there was no significant difference in body height (P = .326). The CCL/ICOFD, CCL/FL, and CCL/VD ratios were significantly decreased in fetuses with MCD when compared with controls (P < .05). The CCL/ICOFD ratio offered the highest predictive accuracy for MCD, yielding an AUC of 0.856 (95% CI: 0.774-0.938, P < .001), followed by CCL/FL ratio (AUC, 0.780 (95% CI: 0.657-0.904), P < .001), CCL/VD ratio (AUC, 0.677 (95% CI: 0.559-0.795), P < .01). CONCLUSION: The corpus callosum biometric parameters in fetuses with MCD are reduced. The CCL/ICOFD ratio derived from sonographic measurements is considered a promising tool for the prenatal detection of cortical malformations. External validation of these findings and prospective studies are warranted.

Prenatal ultrasound findings and prenatal diagnosis of fetal skeletal dysplasia.

OBJECTIVE: To analyze the value of prenatal ultrasound and molecular testing in diagnosing fetal skeletal dysplasia (SD). METHODS: Clinical data, prenatal ultrasound data, and molecular results of pregnant women with fetal SD were collected in the ultrasound department of our clinic from May 2019 to December 2021. RESULTS: A total of 40 pregnant women with fetal SD were included, with 82.5% exhibiting short limb deformity, followed by 25.0% with central nervous system malformations, 17.50% with facial malformations, 15% with cardiac malformations, and 12.5% with urinary system malformations. The genetic testing positive rate was 70.0% (28/40), with 92.8% (26/28) being single-gene disorders due to mutations in FGFR3, COL1A1, COL1A2, EVC2, FLNB, LBR, and TRPV4 genes. The most common SD subtypes were osteogenesis imperfecta (OI), thanatophoric dysplasia (TD), and achondroplasia (ACH). The gestational age (GA) at initial diagnosis for TD, OI, and ACH was 16.6, 20.9, and 28.3 weeks, respectively (p < 0.05), with no significant difference in femoral shortening between the three groups (p > 0.05). Of the OI cases, 5 out of 12 had a family history. CONCLUSION: Short limb deformity is the most prevalent phenotype of SD. When fetal SD is suspected, detailed ultrasound screening should be conducted, combined with GA at initial diagnosis, family history, and molecular evidence, to facilitate more accurate diagnosis and enhance prenatal counseling and perinatal management.

Prenatal diagnosis of pulmonary arteriovenous malformations with a postnatal diagnosis of Osler-Weber-Rendu syndrome.

Hereditary Hemorrhagic Telangiectasia (HHT), commonly known as Osler-Weber-Rendu disease, is an autosomal dominant multisystemic vascular disease associated with approximately 70% of cases of pulmonary arteriovenous malformations (PAVMs). Prenatal cases of PAVMs typically present with pulmonary vein dilatation on ultrasonography. This study presents a prenatal diagnosis of PAVMs with enlarged right pulmonary vein, cardiomegaly, cystic-appearing areas in the right lung and subsequent confirmation of Osler-Weber-Rendu syndrome using autopsy and whole exom sequencing.