The Evaluation of Invasive Prenatal Diagnostic Tests in North Cyprus: A Retrospective Study.

BACKGROUND: Congenital diseases are still an important medical, social, and economic problem all over the world. In North Cyprus, in addition to other reasons, early prenatal diagnostic measures are undertaken to prevent births with thalassemia major, a locally widespread genetic disease. AIM: This study aims to evaluate the results of prenatal invasive diagnostic tests performed in a private obstetrics clinic in Northern Cyprus and show the diagnosis process of thalassemia and chromosomal anomalies. MATERIALS AND METHODS: This study is a retrospective, descriptive study. Chorionic villus sampling (CVS) results and the amniocentesis tests performed between 1990 and 2022 are evaluated. Thalassemia and chromosome analysis of samples obtained by CVS and amniocentesis tests were performed. To diagnose alpha or beta thalassemia and sickle cell, 239 CVS was performed. And to diagnose chromosomal anomalies, 396 CVS and amniocentesis were performed. RESULTS: The mean age of the 480 pregnant women included in the study was 31.12 years (18-46) and 30% of them were older than 34 years. The most common indications for invasive prenatal diagnostic test (IPDT) were; mother/father thalassemia minor/major, advanced maternal age, high risk of ultrasonography erase findings, and the noninvasive screening test. The result of IPDT detected 7.3% chromosomal anomaly and 69.5% thalassemia and sickle cell anemia. Of the 239 CVS performed to diagnose alpha or beta thalasemia and sickle cell, 23.4% beta major, 42.3% beta minor, and 2.1% alpha minor were diagnosed. Of the 396 CVS and amniocentesis performed to diagnose chromosomal anormalies; 2.8% of Down syndrome and 4.54% of other chromosomal anomalies were diagnosed. CONCLUSION: IPDT is important in correctly diagnosing fetal anomalies at the prenatal stage to help families decide at the right time.

Congenital Ichthyosis: Current Approaches to Prenatal Diagnoses.

INTRODUCTION: Congenital ichthyosis represents a wide spectrum of diseases. This article reviews prenatal testing for ichthyosis. METHODS: We used pubmed.ncbi.nlm.nih.gov to search for 38 types of congenital ichthyosis combined with 17 words related to prenatal testing. RESULTS: Search resulted in 408 publications covering 13 types of ichthyoses and four types of tests. DISCUSSION: Biochemical testing is diagnostic in trichothiodystrophy, but nonspecific in X-linked ichthyosis and Refsum syndrome. Except in X-linked ichthyosis, biochemical testing requires invasive procedures to obtain fetal skin biopsy, amniocytes, or chorionic villus samples. It is superior to histological and cytological examination of fetal skin biopsy or amniocytes because keratinization occurs later in pregnancy and microscopy cannot differentiate between ichthyosis types. Imaging is more acceptable due to noninvasiveness and routine use, although ultrasonography is operator-dependent, nonspecific, and captures abnormalities at late stage. Molecular tests are described in at-risk pregnancies but testing of free fetal DNA was not described.

Mosaic trisomy 5 in amniotic fluid in a live fetus with Ebstein anomaly and complete trisomy 5 in chorionic villus sampling.

Complete trisomy 5 is a rare and lethal abnormality. Mosaic trisomy 5 presents in various phenotypes, ranging from a clinically normal fetus to fetuses presenting uterine growth restriction, congenital heart anomalies, multiple dysmorphic features and psychomotor development abnormalities. Although rare, there are cases of a normal psychomotor development regardless of the associated low fetal growth frequently associated with mosaic trisomy 5. This is the first case report to date of a live fetus with complete trisomy 5 reported in chorionic villus sampling and mosaic trisomy 5 in amniotic fluid with a concomitant Ebstein anomaly. Diagnosis of mosaic trisomy 5 represents a challenge for the clinical team and patients, as the information regarding this syndrome is scarce and based mostly on case reports of liveborns, which may introduce a selection bias when counselling the parents.

[Application of flat-sided culture tubes during prenatal diagnosis].

OBJECTIVE: To assess the value of using flat-sided culture tubes for preparing chromosomes through chorionic villi (CV) and amniotic fluid (AF) cell cultures during prenatal diagnosis. METHODS: From February to March 2020, 157 CV samples and 147 AF samples subjected to prenatal diagnosis at the Maternal and Child Health Care Hospital of Guangxi Zhuang Autonomous Region were selected as the study subjects. For each sample, one flat-sided tube and one flask culture were set up by following the standard protocols. The methods were evaluated by comparing the cell growth, experimental process, quality of chromosome preparation and costs. RESULTS: The success rates for the culturing of CV and AF samples by the flat-sided culture tube method were 97.45% (153/157) and 97.96% (144/147), respectively. By contrast, the success rates for the conventional flask method were 98.72% (155/157) for CV and 98.64% (145/147) for AF samples. No significant difference was found between the two methods (P > 0.05). The average harvest time required by the flat-sided culture tube method was 8.45 days for CV and 9.43 days for AF cultures, whilst the average harvest time for conventional flask method was 9.05 days and 9.54 days, respectively. The flat-sided culture tube method for CV had required significantly shorter average harvest time than the conventional method (P < 0.001). No statistical significant difference was found in the average harvest time for AF by the two methods (P > 0.05). The conventional culturing method had required three containers with two sample transfers. By contrast, the flat-sided culture tube method was carried out in one tube without any sample transfer. The average total amount of medium used was 3.91 mL for each flat-sided culture tube and 6.26 mL for each conventional flask. CONCLUSION: The flat-sided culture tube method can provide a simple, cost-effective and error-reducing procedure for the CV and AF samples culture during prenatal diagnosis.

Low-level mosaic trisomy 2 at amniocentesis in a pregnancy associated with positive NIPT and CVS results for trisomy 2, maternal uniparental disomy 2, perinatal progressive decrease of the aneuploid cell line, cytogenetic discrepancy between cultured amniocytes and uncultured amniocytes, intrauterine growth restriction and a favorable fetal outcome.

OBJECTIVE: We present low-level mosaic trisomy 2 at amniocentesis in a pregnancy associated with positive non-invasive prenatal testing (NIPT) and chorionic villus sampling (CVS) results for trisomy 2, maternal uniparental disomy (UPD) 2, perinatal progressive decrease of the aneuploid cell line, cytogenetic discrepancy between cultured amniocytes and uncultured amniocytes, intrauterine growth restriction (IUGR) and a favorable fetal outcome. CASE REPORT: A 35-year-old, primigravid woman underwent amniocentesis at 16 weeks of gestation because both NIPT at 9 weeks of gestation and CVS at 11 weeks of gestation revealed trisomy 2. This pregnancy was conceived by in vitro fertilization (IVF) and embryo transfer (ET). Amniocentesis revealed a karyotype of 47,XY,+2[11]/46,XY[19]. Prenatal ultrasound findings were normal. She was referred to the hospital for genetic counseling at 20 weeks of gestation, and repeat amniocentesis performed at 24 weeks of gestation revealed a karyotype of 46,XY (22/22 colonies). The parental karyotypes were normal. Quantitative fluorescent polymerase chain reaction (QF-PCR) analysis on the DNA extracted from uncultured amniocytes and parental bloods revealed maternal uniparental heterodisomy of chromosome 2. Simultaneous molecular cytogenetic analysis on uncultured amniocytes showed the results of arr 2p25.3q37.3 × 2.4 with a log2 ratio = 0.26, consistent with 40% mosaicism for trisomy 2 by array comparative genomic hybridization (aCGH), and 28% (28/100 cells) mosaicism for trisomy 2 by interphase fluorescence in situ hybridization (FISH). Despite IUGR on fetal ultrasound, the woman was advised to continue the pregnancy, and a 2252-g phenotypically normal male baby was delivered at 38 weeks of gestation. The karyotypes of cord blood, umbilical cord and placenta were 46,XY (40/40 colonies), 46,XY (40/40 colonies) and 47,XY,+2[9]/46,XY[31], respectively. QF-PCR analysis on cord blood, umbilical cord and placenta confirmed uniparental heterodisomy of chromosome 2 in the cord blood and umbilical cord, and maternal origin of trisomy 2 in the placenta. FISH analysis on buccal mucosal cells at age 1.5 months revealed 8.7% (9/104 cells) mosaicism for trisomy 2. When follow-up at age four months, the neonate manifested a normal phenotype except intermittent hypoventilation. Molecular analysis of the PHOX2B gene revealed a normal result. When follow-up at age one year, he manifested normal development. CONCLUSION: Mosaic trisomy 2 at prenatal diagnosis should alert the possibility of UPD 2 and include a UPD 2 testing. Low-level mosaic trisomy 2 at amniocentesis can be associated with perinatal progressive decrease of the aneuploid cell line and a favorable fetal outcome.

Low-level mosaic trisomy 13 at amniocentesis in a pregnancy associated with a positive NIPT result suspicious of trisomy 13, a CVS result of mosaic trisomy 13, cytogenetic discrepancy in various tissues and a favorable fetal outcome.

OBJECTIVE: We present low-level mosaic trisomy 13 at amniocentesis in a pregnancy associated with a positive non-invasive prenatal testing (NIPT) result suspicious of trisomy 13, a chorionic villus sampling (CVS) result of mosaic trisomy 13, cytogenetic discrepancy in various tissues and a favorable fetal outcome. CASE REPORT: A 29-year-old, gravida 2, para 1, woman underwent amniocentesis at 20 weeks of gestation because of a positive NIPT result (Z-score = 20.9, positive ≥3) suspicious of trisomy 13 at 11 weeks of gestation and a CVS result of mosaic trisomy 13 at 14 weeks of gestation. At 14 weeks of gestation, CVS revealed the multiplex ligation-dependent probe amplification (MLPA) result of rea X,Y (P095) × 1, 13 (P095) × 3, 18,21 (P095) × 2/X,Y (P095) × 1, 13,18,21 (P095) × 2 and a karyotype of 48,XY,+13,+mar [9]/47,XY,+mar[16]. She was referred to the hospital for genetic counseling at 15 weeks of gestation, and cytogenetic analysis of parental blood revealed 47,XY,+mar in the father and 46, XX in the mother. Fluorescence in situ hybridization (FISH) analysis on the paternal blood showed that the extra dicentric marker was derived from chromosome 15 without the locus SNRPN (15q11.2), and the result was 47,XY,+mar.ish dic(15) (D15Z1++, SNRPN-, PML-)[20]. Amniocentesis at 20 weeks of gestation revealed a karyotype of 47,XY,+mar pat (20/20). Simultaneous interphase FISH analysis on uncultured amniocytes revealed 32% (32/100 cells) mosaicism for trisomy 13. Quantitative fluorescence polymerase chain reaction (QF-PCR) analysis using the DNA extracted from the parental bloods and uncultured amniocytes excluded uniparental disomy (UPD) 13. Prenatal ultrasound findings were normal. The woman was advised to continue the pregnancy, and a phenotypically normal 2708-g male baby was delivered at 38 weeks of gestation, The cord blood, umbilical cord and placenta had the karyotypes of 47,XY,+mar pat and did not have UPD 13. When follow-up at age two months, the neonate was phenotypically normal. FISH analysis on buccal mucosal cells detected 5.3% (5/95 cells) mosaicism for trisomy 13, compared with 0% in the normal control. CONCLUSION: Low-level mosaic trisomy 13 at amniocentesis can be associated with a positive NIPT result suspicious of trisomy 13, a CVS result of mosaic trisomy 13, cytogenetic discrepancy in various tissues and a favorable fetal outcome.

A decade of change - lessons learned from prenatal diagnostics in Central Denmark region in 2008-2018.

INTRODUCTION: In 2011, it was decided to implement chromosomal microarray in prenatal testing in the Central Denmark Region, mainly due to the expected higher diagnostic yield. Chromosomal microarray was introduced gradually for an increasing number of pregnancies and without a transition period where both karyotyping and chromosomal microarray were performed: first malformations (2011), then large nuchal translucency (2013), then high risk at combined first trimester risk screening (2016) and finally for all indications (2018). This retrospective study summarizes 11 years of using chromosomal microarray in invasive prenatal testing and presents the effect on diagnostic yield and turnaround time. Furthermore, the concerns when introducing chromosomal microarray are presented and discussed. MATERIAL AND METHODS: Registry data from the Danish Fetal Medicine Database, the regional fetal medicine database, the Danish Cytogenetic Central Register and the local laboratory database at Department of Clinical Genetics were all combined, and a cohort of 147 158 singleton pregnancies with at least one ultrasound examination was established RESULTS: Of the 147 158 pregnancies, invasive sampling was performed (chorionic villi or amniocytes) in 8456, corresponding to an overall invasive rate of 5.8%. Between 2016 and 2018, 3.4% (95% confidence interval [CI] 2.8-4.2%; n = 86) of the invasive samples (n = 2533) had a disease causing copy number variant and 5.3% (95% CI 4.4-6.2%; n = 133) had trisomies and other aneuploidies. The turnaround time more than halved from 14 days to an average of 5.5 days for chorionic villus sampling. CONCLUSIONS: Chromosomal microarray identified 5.3% trisomies and 3.4% copy number variants, thereby increased the diagnostic yield by more than 64% compared with karyotype only and it also more than halved the turnaround time. Some preliminary concerns proved real, eg prenatal counseling complexity, but these have been resolved over time in a clinical path with expert consultations.

Experience in prenatal genetic testing and reproductive decision-making for monogenic disorders from a single tertiary care genetics clinic in a low-middle income country.

OBJECTIVES: Explore health-care seeking behaviour among couples with pregnancies at-risk of monogenic disorders and compare time duration for obtaining Prenatal Genetic Test (PGT) results based on (i) amniocentesis and Chorionic Villus Sampling (CVS) (ii) in-house testing and out-sourced testing. Report the spectrum of monogenic disorders in our cohort. METHODS: Medical records of women consulting prenatal genetic counselling clinic at Aga Khan University Hospital, Karachi from December-2015 to March-2021 with history of miscarriage or a monogenic disorder in previous children were reviewed. RESULTS: Forty-three pregnancies in 40 couples were evaluated, 37(93%) were consanguineous. Twenty-five (63%) couples consulted before and 15(37%) after conception. Thirty-one (71%) pregnancies underwent CVS at the mean gestational age of 13-weeks and 6-days ± 1-week and 3-days and amniocentesis at 16-weeks and 2-days ± 1-week and 4-days. PGT for 30 (70%) pregnancies was outsourced. The mean number of days for in-house PGT was 16.92 ± 7.80 days whereas for outsourced was 25.45 ± 7.7 days. Mean duration from procedure to PGT result was 20.55 days after CVS compared to 28.75 days after amniocentesis. Eight (18%) fetuses were homozygous for disease-causing variant for whom couples opted for termination of pregnancy (TOP). Twenty-six monogenetic disorders were identified in 40 families. CONCLUSION: Proactive health-care seeking behaviour and TOP acceptance is present amongst couples who have experienced a genetic disorder.

How does cell-based non-invasive prenatal test (NIPT) perform against chorionic villus sampling and cell-free NIPT in detecting trisomies and copy number variations? A clinical study from Denmark.

OBJECTIVES: We aimed to compare cell-based NIPT (cbNIPT) to chorionic villus sampling (CVS) and to examine the test characteristics of cbNIPT in the first clinical validation study of cbNIPT compared to cell-free NIPT (cfNIPT). MATERIAL AND METHODS: Study 1: Women (N = 92) who accepted CVS were recruited for cbNIPT (53 normal and 39 abnormal). Samples were analyzed with chromosomal microarray (CMA). Study 2: Women (N = 282) who accepted cfNIPT were recruited for cbNIPT. cfNIPT was analyzed using sequencing and cbNIPT by CMA. RESULTS: Study 1: cbNIPT detected all aberrations (32/32) found in CVS: trisomies 13, 18 and 21 (23/23), pathogenic copy number variations (CNVs) (6/6) and sex chromosome aberrations (3/3). cbNIPT detected 3/8 cases of mosaicism in the placenta. Study 2: cbNIPT detected all trisomies found with cfNIPT (6/6) and had no false positive (0/246). One of the three CNVs called by cbNIPT was confirmed by CVS but was undetected by cfNIPT, two were false positives. cbNIPT detected mosaicism in five samples, of which two were not detected by cfNIPT. cbNIPT failed in 7.8% compared to 2.8% in cfNIPT. CONCLUSION: Circulating trophoblasts in the maternal circulation provide the potential of screening for aneuploidies and pathogenic CNVs covering the entire fetal genome.

Severe maternal thrombocytopenia and prenatal invasive procedures: still a grey zone.

Management of severe thrombocytopenia, particularly of ITP, in pregnancy is mainly based on expert consensus and clinical experience while there are no clear indications about the minimum platelet count requested for prenatal diagnosis invasive procedures. Since the lack of specific recommendations we reported our clinical management of a patient suffering from severe thrombocytopenia, undergoing amniocentesis. Due to the anecdotic possibility of maternal and fetal bleeding in case of severe thrombocytopenia, prophylaxis with IVIG or even corticosteroids could be considered as a safer strategy to prevent post-procedural adverse outcomes.

[Chronic granulomatous villitis due to cytomegalovirus. An unusual finding that may cause confusion. A case report]. / Villitis crónica granulomatosa asociada a citomegalovirus. Un hallazgo inusual que induce a confusión. A propósito de un caso.

Chronic cytomegalovirus (CMV) villitis typically causes inflammation with predominance of plasma cells. The granulomatous reaction in the chorionic villi is usually caused by pathogens other than CMV, such as toxoplasma or rubella. We present a case of a pregnant woman presenting with foetal death in the twentieth week of gestation. The study of the placenta revealed chronic CMV villitis with a granulomatous reaction, rather than the more common plasma cell inflammation.

DEGUM Recommendations on Diagnostic Puncture in Prenatal Medicine. / Empfehlungen der DEGUM zu diagnostischen Punktionen in der Pränatalmedizin.

Diagnostic puncture (amniocentesis, chorionic villus sampling, and fetal blood sampling) is an essential part of prenatal diagnostics and the only established and sufficiently scientifically evaluated possibility of diagnosing genetic diseases from pregnancy-specific cells. The number of diagnostic punctures in Germany, as in other countries, has fallen significantly. This is largely due to the introduction of first-trimester screening with further detailed ultrasound examination of the fetus and the analysis of cf-DNA (cell-free DNA) from maternal blood (noninvasive prenatal test - NIPT). On the other hand, knowledge about the incidence and appearance of genetic diseases has increased. The development of modern molecular genetic techniques (microarray and exome analysis) makes a differentiated investigation of these diseases increasingly possible. The requirements for education and counseling regarding these complex correlations have thus increased. The studies performed in recent years make it clear that diagnostic puncture performed in expert centers is associated with a low risk of complications. In particular, the procedure-related miscarriage risk hardly differs from the background risk for spontaneous abortion. In 2013, the Section of Gynecology and Obstetrics of the German Society for Ultrasound in Medicine (DEGUM) published recommendations on diagnostic puncture in prenatal medicine 1. The developments described above and new findings in recent years make it necessary to revise and reformulate these recommendations. The aim of this review is to compile important and current facts regarding prenatal medical puncture (including technique, complications, genetic examinations). It is intended to provide basic, comprehensive, and up-to-date information on diagnostic puncture in prenatal medicine. It replaces the publication from 2013 1.

A Multi-centre Experience of Trans-abdominal Chorionic Villus Sampling in Pakistan.

OBJECTIVE: To determine the safety and outcomes of trans-abdominal chorionic villus sampling technique. STUDY DESIGN: Observational study. PLACE AND DURATION OF STUDY: Departments of Obstetrics and Gynaecology, PNS Shifa Karachi, Pak-Emirates Military Hospital Rawalpindi and CMH Lahore, from 2005-2020.   Methodology: A total of 1530 consecutive chorionic villus samplings (CVS) were performed on pregnant females between 10-20 weeks of gestation using the transabdominal approach. Patients were subjected to integrated, stepwise sequential screening. Analysis of data was based on demographic features, indications for sampling, gestational age, attempts of CVS, needle aspiration time, assessment, placental location, sample yield, complications, pain estimation by visual analogue scale (VAS), CVS culture results and pregnancy outcomes. RESULTS: The most common indication for CVS was couple having thalassemia traits and history of having a thalassemia major child previously (55.2%). Pain was the most common complication (64.1%). Procedure-related pregnancy loss (considered to be till 20 weeks of gestation) was observed in two cases (0.1%) only. The most common abnormal karyotype was found to be ß-Thalassemia trait (23.6%) followed by ß-Thalassemia major (22.1%) and Trisomy 21(16.8%). No abnormality was detected in 33.5% of the cases. Five hundred and eighty-nine (38.4%) interruptions of pregnancies were done on the basis of CVS results. CONCLUSION: CVS is a safe and useful technique for sampling in prenatal diagnosis of genetic disorders, markedly affecting the management. KEY WORDS: Chorionic villus sampling, Pre-natal diagnosis, Karyotype.

Resultados perinatales tras prueba diagnóstica invasiva en el embarazo / Perinatal outcomes after invasive diagnostic test in pregnancy

Introducción: Las técnicas invasivas de diagnóstico prenatal nos permiten realizar pruebas genéticas. El desarrollo de técnicas no invasivas ha reducido su uso. Clásicamente se ha afirmado que, tras realizar la técnica invasiva, la tasa de pérdida fetal se sitúa en torno al 1%. Los datos publicados son heterogéneos, y aunque todo indica que se ha sobrestimado el riesgo, necesitamos realizar nuevos estudios. Material y métodos: En nuestro estudio retrospectivo unicéntrico analizamos los procedimientos realizados mediante técnicas invasivas de diagnóstico prenatal entre 2011 y 2019, incluyendo 832 técnicas invasivas realizadas. Los resultados perinatales se comparan con el grupo control de mujeres embarazadas (n=1.734). Resultados: La tasa de pérdida fetal temprana para las diferentes técnicas fue de 1,1% para amniocentesis, del 1,6% para biopsia corial transvaginal y del 0,5% para biopsia corial abdominal, con una tasa total del 1,1%, sin diferencias estadísticamente significativas entre ellas (p=0,57). Encontramos diferencias en el desenlace fetal, en cuanto a la variable pérdida fetal temprana, en relación con los intentos realizados (cuando se hacían tres intentos aumentaba el riesgo). Al comparar los resultados perinatales posparto del grupo sometido a técnicas con el grupo control, se encontró una mayor tasa de cesáreas en el grupo estudio (28,9% vs 20,5%), además de una menor edad gestacional media al parto (38,33 vs. 38,95 semanas). Discusión: Cuando la técnica invasiva se realiza en el momento adecuado y con no más de dos intentos, consideramos que el riesgo de pérdida fetal no se ve afectado por su realización, siendo igual al de la población general.(AU)

Introduction: Invasive prenatal diagnostic techniques allow us to conduct genetic tests. The development of non-invasive techniques has reduced their use. The foetal loss rate following an invasive procedure is considered to be around 1%. The published data is heterogeneous however, although everything indicates that the risk has been overestimated, we need to conduct further studies. Material and methods: In our single-centre retrospective study we analysed the procedures carried out using invasive prenatal diagnostic techniques between 2011 and 2019. A total of 832 invasive techniques were performed. Perinatal results are compared with a control group of pregnant women (n=1734). Results: The early foetal loss rate for the different techniques were 1.1% for amniocentesis, 1.6% for transvaginal chorionic biopsy and 5% for abdominal chorionic biopsy, with a total rate of 1.1%, without statistically significant differences between them (P=.57). We found differences in foetal outcome, in terms of variable early foetal loss, related to the attempts made (when three attempts were made, the risk increased). When comparing the perinatal outcomes after delivery of the group that underwent techniques with the control group, a higher rate of caesarean sections was found in the study group (28.9% vs 20.5%), in addition to lower mean gestational age at delivery (38.33 vs. 38.95 weeks). Discussion: When the invasive technique is performed at the right time and with no more than two attempts, we consider that the risk of foetal loss is not affected, and is equal to that of the general population.(AU)

State-wide increase in prenatal diagnosis of klinefelter syndrome on amniocentesis and chorionic villus sampling: Impact of non-invasive prenatal testing for sex chromosome conditions.

BACKGROUND: To analyze population-based trends in the prenatal diagnosis of sex chromosome aneuploidy (SCA) since the availability of non-invasive prenatal testing (NIPT). METHODS: Retrospective state-wide data for all prenatal diagnoses performed <25 weeks gestation from 2005 to 2020 in Victoria, Australia. Non-invasive prenatal testing became locally available from 2012. The prenatal diagnosis rates of SCA as proportions of all prenatal diagnostic tests and all births were calculated. Statistical significance was assessed with the χ2 test for trend, with p < 0.05 considered significant. RESULTS: 46,518 amniocentesis and chorionic villus sampling were performed during the study period, detecting 617 SCAs. There was a significant increase in the rate of prenatal SCAs from 5.8 per 10,000 births in 2005 to 8.7 per 10,000 births in 2020 (p < 0.0001). This increase was predominantly due to 47,XXY cases, 91% of which were ascertained via positive NIPT for this condition in 2020. The prenatal diagnosis rate of 47,XXY significantly increased from 0.8 per 10,000 births in 2005 to 4.3 per 10,000 births in 2020 (p < 0.0001). CONCLUSION: Screening for SCAs using NIPT has directly led to an increase in their prenatal diagnosis on a population-wide basis, especially 47,XXY. This has implications for clinician education, genetic counselling, and pediatric services.

Tricky TRIC: A replication study using trophoblast retrieval and isolation from the cervix to study genetic birth defects.

OBJECTIVE: Noninvasive Prenatal Diagnosis has recently been introduced for a limited number of monogenetic disorders. However, the majority of DNA diagnostics still require fetal material obtained using an invasive test. Recently, a novel technique, TRIC (Trophoblast Retrieval and Isolation from the Cervix), has been described, which collects fetal trophoblast cells by endocervical sampling. Since this technique has not been successfully replicated by other groups, we aimed to achieve this in the current study. METHOD: Pregnant women referred for transvaginal chorionic villous sampling (CVS) were asked for an endocervical sample prior to CVS. The TRIC samples were processed to isolate trophoblast DNA. TRIC DNA was used in ForenSeq to determine the amount of maternal DNA contamination, and for Sanger sequencing in case of a monogenic disorder. RESULTS: 23%-44% of samples had a sufficiently high fetal DNA fraction to allow genetic testing, as calculated by Sanger sequencing and ForenSeq, respectively. CONCLUSION: We have been able to successfully replicate the TRIC protocol, although with a much lower success rate as described by the original study performing TRIC. As we obtained the samples in the actual clinical setting envisioned, the method in its current setup is not advisable for use in prenatal diagnostics.

Invasive Prenatal Diagnostic Testing for Aneuploidies in Singleton Pregnancies: A Comparative Review of Major Guidelines.

Sophisticated screening protocols for genetic abnormalities constitute an important component of current prenatal care, aiming to identify high-risk pregnancies and offer appropriate counseling to parents regarding their options. Definite prenatal diagnosis is only possible by invasive prenatal diagnostic testing (IPDT), mainly including amniocentesis and chorionic villous sampling (CVS). The aim of this comparative review was to summarize and compare the existing recommendations on IPDT from the most influential guidelines. All the reviewed guidelines highlight that IPDT is indicated based on a positive screening test rather than maternal age alone. Other indications arise from medical history and sonography, with significant variations identified between the guidelines. The earlier time for amniocentesis is unequivocally set at ≥15 gestational weeks, whereas for CVS, the earlier limit varies from ≥10 to ≥11 weeks. Certain technical aspects and the overall approach demonstrate significant differences. Periprocedural management regarding Rhesus alloimmunization, virologic status and use of anesthesia or antibiotics are either inconsistent or insufficiently addressed. The synthesis of an evidence-based algorithm for IPDT is of crucial importance to healthcare professionals implicated in prenatal care to avoid unnecessary interventions without compromising optimal prenatal care.

Increased use of diagnostic testing after increased nuchal translucency: The influence of non-invasive prenatal testing and chromosomal microarray.

OBJECTIVE: The utilization of non-invasive prenatal testing (NIPT) and chromosomal microarray (CMA) has significantly altered the options for testing following the diagnosis of an increased nuchal translucency (NT). This study defines the rates of utilization of diagnostic testing in the pre-NIPT, pre-CMA, and post-CMA eras. METHODS: We retrospectively examined NT scans performed in our department from January 2010 to December 2020 and identified all NTs ≥3.0 mm for analysis. We divided our data into three distinct periods (2010-2012, 2013-2016, and 2017-2020) corresponding to our institutional practice shifts in recommending and offering use of NIPT (2013) and CMA (2016), respectively. RESULTS: 689 patients with NT ≥ 3.0 mm met inclusion criteria in our study, of which 355 (51.5%) individuals underwent diagnostic testing and 334 (48.5%) did not. There was a significant decline in rates of diagnostic testing with NIPT (2013), which has returned to pre-NIPT levels with the availability of microarray. CONCLUSIONS: Since the routine use of CMA (2016), the rates of diagnostic testing for increased NT have returned to pre-NIPT levels. This study validates data suggesting an initial decline in the rates of diagnostic testing following abnormal NT but suggests that the decline may be reversing in the post-CMA era due to a rise in rates of chorionic villus sampling.

Prenatal genetic testing 2: diagnostic tests.

PURPOSE OF REVIEW: Prenatal genetic testing can be divided into two categories: screening and diagnosis. Prenatal genetic screening tests are used to assess carrier status or as a fetal risk assessment for a particular genetic disorder [1]. Prenatal genetic diagnostic testing is used to diagnose particular genetic conditions with as much certainty as possible [1,2]. This review will focus on the diagnostic side of prenatal genetic testing. RECENT FINDINGS: Next generation sequencing (NGS) has revolutionized prenatal genetic diagnostic testing. NGS methods are becoming more advanced and accurate as more genetic information is being linked to genetic conditions. SUMMARY: Prenatal genetic diagnostic testing involves clinicians invasively obtaining tissue via amniocentesis or chorionic villus sampling to identify if a fetus has a genetic condition. This testing has traditionally been done through fluorescence in-situ hybridization, karyotype, or chromosomal microarray analysis. However, genetic testing is in a time of rapid technologic expansion and new methods like NGS, which includes targeted gene panels, whole exome sequencing, and whole genome sequencing are being used too. In this time of growth, it is important that providers educate themselves on the research support and indication behind each type of genetic diagnostic test.

Foetal loss after chorionic villus sampling and amniocentesis in twin pregnancies: A multicentre retrospective cohort study.

OBJECTIVE: We aimed to determine foetal losses for DCDA and MCDA twins following transabdominal CVS or amniocentesis performed <22+0  weeks. METHODS: Retrospective cohort study conducted in the UK and Belgium 01/01/00-01/06/20. Cases with unknown chorionicity, monochorionic complications or complex procedures were excluded. Uncomplicated DCDA and MCDA twins without invasive procedures were identified as controls. We reported foetal losses <24+0  weeks and losses of genetically and structurally normal foetuses. RESULTS: Outcomes were compared for DCDA foetuses; 258 after CVS with 3406 controls, 406 after amniocentesis with 3390 controls plus MCDA foetuses, 98 after CVS with 1124 controls, and 160 after amniocentesis with 1122 controls. There were more losses <24+0  weeks with both procedures in DCDA (CVS RR 5.54 95% CI 3.38-9.08, amniocentesis RR 2.36 95% CI 1.22-4.56) and MCDA twins (CVS RR 5.14 95% CI 2.51-10.54, amniocentesis RR 7.01 95% CI 3.86-12.74). Losses of normal foetuses were comparable to controls (DCDA CVS RR 0.39 95% CI 0.05-2.83, DCDA amniocentesis RR 1.16 95% CI 0.42-3.22, MCDA CVS RR 2.3 95% CI 0.71-7.56, and MCDA amniocentesis RR 1.93 95% CI 0.59-6.38). CONCLUSIONS: This study indicates increased foetal losses for DCDA and MCDA twins following CVS and amniocentesis with uncertain risk to normal foetuses.