Noninvasive Prenatal Testing for Trisomies 21, 18, and 13, Sex Chromosome Aneuploidies,and Microdeletions in Average-Risk Pregnancies: A Cost-Effectiveness Analysis

ObjectiveThe cost effectiveness of noninvasive prenatal testing (NIPT) has been established for high-risk pregnancies but remains unclear for pregnancies at other risk levels. The aim was to assess the cost effectiveness of NIPT in average-risk pregnancies from the perspective of a provincial public payer in Canada.MethodsA model was developed to compare traditional prenatal screening (TPS), NIPT as a second-tier test (performed only after a positive TPS result), and NIPT as a first-tier test (performed instead of TPS) for trisomies 21, 18, and 13; sex chromosome aneuploidies; and microdeletions in a hypothetical annual population cohort of average-risk pregnancies (142 000 to 148,000) in Ontario, Canada. A probabilistic analysis was conducted with 5000 repetitions.ResultsCompared with TPS, NIPT as a second-tier test detected more affected fetuses with trisomies 21, 18, and 13 (188 vs. 158), substantially reduced the number of diagnostic tests (i.e., chorionic villus sampling and amniocentesis) performed (660 vs. 3107), and reduced the cost of prenatal screening ($26.7 million vs. $27.6 million) annually. Compared with second-tier NIPT, first-tier NIPT detected an additional 80 cases of trisomies 21, 18, and 13 at an additional cost of $33 million. The incremental cost per additional affected fetus detected was $412 411. Extending first-tier NIPT to include testing for sex chromosome aneuploidies and 22q11.2 deletion would increase the total screening cost.ConclusionsNIPT as a second-tier test is cost-saving compared with TPS alone. Compared with second-tier NIPT, first-tier NIPT detects more cases of chromosomal anomalies but at a substantially higher cost.     

Noninvasive prenatal detection of fetal sex chromosome abnormalities using the semiconductor sequencing platform (SSP) in Southern China

BackgroundNoninvasive prenatal testing (NIPT) has been widely used to screen for fetal aneuploidies, including fetal sex chromosome aneuploidies (SCAs). However, there is less information on the performance of NIPT in detecting SCAs.MethodsA cohort of 47,800 pregnancies was recruited to review the high-risk NIPT results for SCAs. Cell-free fetal DNA (cffDNA) was extracted and sequenced. All NIPT high-risk cases were recommended to undergo invasive prenatal diagnosis for karyotyping analysis and chromosome microarray analysis (CMA).ResultsA total of 238 high-risk cases were detected by NIPT, including 137 cases of 45,X, 27 cases of 47,XXX, and 74 cases of 47,XYY/47,XXY. Prenatal diagnosis, including karyotyping analysis and CMA, was available in 170 cases. The positive predictive value (PPV) was 30.00% for 45,X, 70.58% for 47,XXX, and 81.13% for 47,XYY/47,XXY. In addition, 13 cases of sex chromosome mosaicism and 9 cases of sex chromosome CNVs were incidentally found in this study.ConclusionOur study showed that NIPT was reliable for screening SCAs based on a large sample, and it performed better in predicting sex chromosome trisomies than monosomy X. Our study will provide an important reference for clinical genetic counseling and further processing of the results.     

Association of non-invasive prenatal testing and chromosomal microarray analysis for prenatal diagnostics

Abstract

The purposes of this study is to examine possibility to use combination of non-invasive prenatal testing (NIPT) and chromosomal microarray analysis (CMA) for prenatal diagnostics and their advantages between combined first-trimester screen with confirmation by karyotyping of CVS or amniocytes. A total of 1968 pregnant women, in this study, have undergone prenatal screening and/or diagnostic tests. NIPT is more suitable and efficient for the detection of aneuploidy. However, this test has limitations for detection deletions/duplications. Use of CMA for confirmation of some NIPT findings or as first test for women with ultrasound abnormalities can detect small imbalances in chromosomes. Combination of NIPT and CMA allows a higher prenatal detection of chromosomal abnormalities.     

Sonographic abnormalities in pregnancies conceived following IVF with and without preimplantation genetic testing for aneuploidy (PGT-A)

Purpose

To report the rate of fetal anomalies detected on anatomy ultrasound in pregnant patients who underwent IVF with preimplantation genetic testing for aneuploidy (PGT-A) compared to patients who conceived following IVF with unscreened embryos and age-matched patients with natural conceptions.

Methods

Retrospective cohort study at a single maternal-fetal medicine practice. Patients with singleton pregnancies who had a mid-trimester anatomy ultrasound between January 2017 and December 2018 were screened for inclusion. A total of 712 patients who conceived after IVF with or without PGT-A were age-matched with natural conception controls. The primary outcome was the rate of fetal and placental anomalies detected on mid-trimester anatomical survey. Secondary outcomes included the rates of abnormal nuchal translucency (NT), second trimester serum analytes, non-invasive prenatal testing (NIPT), and invasive diagnostic testing.

Result(s)

There were no differences in the rate of fetal anomalies in patients who underwent IVF with PGT-A compared to patients who conceived following IVF with unscreened embryos and age-matched patients with natural conceptions. Rate of abnormal NT, high-risk NIPT, and abnormal invasive diagnostic testing were also similar. Patients who conceived after IVF with or without PGT-A had higher rates of abnormal placental ultrasound findings and abnormal second trimester serum analytes compared to natural conception controls.

Conclusion

The use of PGT-A was not associated with a difference in risk of fetal anomaly detection on a mid-trimester anatomical survey. The results of this study highlight the importance of improved patient counseling regarding the limitations of PGT-A, and of providing standard prenatal care for pregnancies conceived through ART, regardless of whether PGT-A was performed.

     

染色体微阵列分析在无创产前筛查非整倍体高风险中的应用价值

目的:探讨染色体微阵列分析(CMA)技术在无创产前筛查(NIPT)提示非整倍体高风险胎儿的产前诊断中的应用价值。方法:241例NIPT提示胎儿染色体非整倍体高风险的孕妇,经羊膜腔或绒毛穿刺获取胎儿细胞,进行CMA分析。对于NIPT提示21-三体和性染色体非整倍体高风险的孕妇根据筛查原因(高龄筛查组、唐筛异常或超声软指标异常组、非高龄筛查组)进行组间NIPT阳性预测值的比较,并对CMA检测提示有染色体拷贝数变异(CNV)的病例进行致病性分析。结果:NIPT对于染色体非整倍体总的阳性预测值为76.3%。NIPT对于21-三体、18-三体、13-三体和性染色体非整倍体的阳性预测值分别为95.0%、88.8%、75.0%和53.3%。经CMA分析确认,在101例NIPT提示21-三体高风险病例中,以高龄筛查组阳性预测值最高(100.0%),3组间比较,差异有统计学意义(P=0.001)。在90例NIPT提示性染色体非整倍体高风险病例中,仍以高龄筛查组阳性预测值最高(61.9%),3组间比较,差异有统计学意义(P=0.002)。12例NIPT提示染色体非整倍体高风险经CMA检测存在CNV。结论:对于21-三体和性染色体非整倍体,不同人群中高龄组的NIPT阳性预测值最为显著,临床上对于此类人群,更要引起足够的重视,做好跟踪随访。CMA较传统的染色体核型分析能额外检出CNV,更能提高染色体结构异常的检出率。     

Prenatal diagnosis of 17q12 duplication and deletion syndrome in two fetuses with congenital anomalies

ObjectiveThe objective of this study was to characterize the genetic abnormalities in two fetuses with congenital anomalies in prenatal screening.Materials and methodsThe mother of Fetus 1 was 26 years old and had a second trimester serum screening that indicated the fetus was at low risk. The prenatal ultrasound and magnetic resonance imaging (MRI) at 28 weeks of gestation showed mild ventriculomegaly, microcephaly, and agenesis of the corpus callosum. The mother of Fetus 2 was 25 years old and also had a second trimester serum screening that indicated the fetus was at low risk. The prenatal ultrasound at 32 weeks of gestation showed the presence of hyperechogenic and enlarged kidneys with multicystic renal dysplasia bilaterally and a persistent left superior vena cava (PLSVC). Both pregnant women underwent cord blood samplings because of the abnormal imaging results. Karyotype analysis revealed normal results in the two fetuses. Chromosome microarray analysis (CMA) was then performed to provide genetic analysis of the cord blood and parental blood samples. Ultimately, the pregnancies were both terminated.ResultsCMA detected a 1.56-Mb duplication at 17q12 in Fetus 1 and a 1.93-Mb deletion of 17q12 in Fetus 2. Both the duplicated and deleted regions included the HNF1B and LHX1 genes. Neither the duplication nor deletion was inherited from the parents.ConclusionThis study is the first to report the prenatal diagnosis of a 17q12 duplication syndrome. Our results further confirmed that genes in this region, including HNF1B and LHX1, are essential for normal brain and kidney development, and also indicated some genes that may be associated with the cardiovascular abnormality. Combined with imaging examination, the use of CMA will improve the diagnosis of submicroscopic chromosomal aberrations in fetuses with congenital anomalies.     

Clinical utility of chromosomal microarray analysis in prenatal diagnosis: report of first 6 months in clinical practice

Abstract

Objective: We studied the clinical utility of chromosomal microarray analysis (CMA) in prenatal diagnosis in a clinical setting in New York City.

Methods: Our center began offering CMA to pregnant women undergoing invasive diagnostic procedures for an abnormal structural finding on ultrasound, maternal age of 35 years or older, or elevated risk on aneuploidy screening, beginning March 2012. Our first six months experience is reported.

Results: Benign familial variants were the most common finding (16/22 fetuses). Variants of uncertain significance were frequent, especially when fathers were not available for testing (4/22 fetuses). Most patients undertook CMA as part of evaluation of an ultrasound anomaly (52%). One patient terminated a pregnancy based on an ultrasound finding in the setting of a benign familial variant on CMA, and a second terminated a pregnancy based on a copy number variant identified on CMA.

Conclusion: For CMA to be maximally useful in prenatal diagnosis, parental DNA samples as well as robust datasets to provide predictive phenotypic information are required. The most common reason for undertaking CMA was to evaluate an ultrasound anomaly, and benign familial variants were a common finding. Genetic services are required to provide pre- and post-test genetic counseling and help families interpret results.     

Cell-free DNA test for pathogenic copy number variations: A retrospective study

ObjectiveTo evaluate the detection rate (DR) by prenatal cell-free DNA test for pathogenic copy number variations (CNVs)＞2 Mb among pregnancies with fetal ultrasound abnormalities.Materials and methodsThis was a retrospective study on 29 pregnant women with fetuses diagnosed as microdeletion/microduplication syndromes by prenatal chromosome microarray analysis (CMA). Cell-free DNA from the maternal plasma was sequenced on the NextSeq CN500 sequencer. The quality standard of unique map reads in a single sample was greater than 10 M and only gains and losses of more than 2 Mb were reported.ResultsA total of 24 CNVs were identified by cell-free DNA test among the 21 fetuses with pathogenic CNVs identified by prenatal CMA, including 20 consistent CNVs and 4 inconsistent CNVs. Overall, the DR of cell-free DNA test for pathogenic CNVs ＞2 Mb was 69%. Microdeletions or microduplications at 22q11.2 were the most common CNVs, with a DR of 4/5 (80%) and 3/4 (75%) respectively.ConclusionCell-free DNA test exhibited a moderate DR for pathogenic CNVs ＞2 Mb among fetuses with ultrasound abnormalities. Cell-free DNA test could provide an opportunity for early screening before the appearance of abnormalities on fetal ultrasound, while further clinical data and cost-effectiveness assessment are needed.     

The role of ultrasound in women with a positive NIPT result for trisomy 18 and 13

ObjectiveThe aim of this study was to evaluate the usefulness of ultrasound in pregnancies with a positive non-invasive prenatal testing (NIPT) result for trisomy 18/13.Materials and methodsDuring a four-year period, the pregnant women who were referred for invasive genetic testing because of positive NIPT results for trisomy 18/13 were included in this study. An in-depth ultrasound was done for these patients before invasive procedures. The data of fetal ultrasound and cytogenetic results were collected.ResultsThere were 81 patients with a positive NIPT result for trisomy 18/13, including 39 (30 positive for trisomy 18; 9 positive for trisomy 13) within 12–14 weeks of gestation, and 42 (31 positive for trisomy 18; 11 positive for trisomy 13) within 15–22 weeks. The PPV of NIPT was 60.7% for trisomy 18, and 30% for trisomy 13, respectively. When adding ultrasound to NIPT, the new PPV for trisomy 18 was 100%, and the negative predictive value (NPV) was 92.3%, with a NPV of 85.7% in the first trimester and a NPV of 100% in the second trimester, respectively. The new PPV and NPV for trisomy 13 were 100% and 100%, respectively.ConclusionBy adding ultrasound to the NIPT, we achieved much higher PPVs and NPVs for trisomy 18/13. A normal scan can help to alleviate stress in parents caused by false positive NIPT results.     

Molecular cytogenetic characterization of 16p11.2 microdeletions with diverse prenatal phenotypes: Four cases report and literature review

ObjectiveChromosome 16p11.2 deletions have been recognized as a genetic disorder with well-described postnatal phenotypes. However, the prenatal manifestations are atypical for lacking of enough evidence.Case reportFour pregnant women underwent amniocentesis for cytogenetic analysis and chromosomal microarray analysis (CMA) because of various indications for prenatal diagnosis: prenatal ultrasound abnormalities (cases 1, 2 and 4) and the childbearing history of cerebral palsy child (case 3). No overlapping phenotypes were observed in cases 1, 2 and 4, which might indicate phenotypic diversities in prenatal phenotypes for 16p11.2 microdeletion. All four fetuses showed normal karyotypic results while CMA identified 0.303–0.916 Mb microdeletions of 16p11.2, encompassing BP2–BP3 and BP4–BP5 regions separately. According to the parental CMA verification, case 1 carried a maternal inherited duplication in the region of Xp22.33 and a de novo deletion in the region of Xp21.1. All parents opted for the termination of pregnancies based upon genetic counselling.ConclusionOur findings enriched the intrauterine phenotypic features of 16p11.2 microdeletions, which would be beneficial for genetic counselling in clinic. In addition, preimplantation genetic testing was recognized as a first-tier approach for such carriers if they intended to conceive again.     

Prenatal cytogenetic diagnosis in amniocentesis.

From 1982 to 1990, cytogenetic studies were successfully conducted in 2,975 (96.19%) of the 3,096 pregnant women who underwent amniocentesis. The average maternal age was 33.7 years and the average gestational age was 18.1 weeks. Common indications of amniocentesis included advanced maternal age (AMA) (54.76%), previous fetus with chromosomal aberrations (6.82%) or gross anomalies (5.01%), intrauterine gross anomaly (4.97%) and maternal exposure to drugs or radiation (5.28%). Among the 89 cases (2.99%) with detected chromosomal aberrations, 53 were numeric (31 trisomies, 21 sex chromosome aberrations and one tripoidy) and 36 were structural (six de novo and 30 hereditary structural rearrangement). The incidence of chromosomal aberrations was 2.03% in cases with AMA. While only four of the 143 cases with previous fetal trisomy 21 had recurrence, the recurrent rate was 90.91% in 11 cases with previous fetal chromosomal translocation. Thirty (20.27%) of the 148 cases with abnormal sonograms showed chromosomal aberrations. Certain congenital anomalies are closely associated with cytogenetic changes: duodenal atresia and trisomy 21; cystic hygroma and 45,X; and polyhydramnios and trisomy 18. Only two of the 157 cases with indications of drug or radiation exposure had abnormal cytogenetic studies. Two of the 53 cases with detected numerical aberrations (47,XXY and 47,XXX) and 27 cases with hereditary structural rearrangement elected to continue their pregnancies. All of these babies were delivered without gross anomalies. This study suggests that for prenatal diagnosis. However, complementary measures, such as routine antenatal ultrasound and maternal serum alphafetoprotein, should be added to increase the efficacy of genetic amniocentesis.     

Nichtinvasive Pränataltestung (NIPT)

Non-invasive prenatal testing (NIPT) using cell-free fetal DNA (cff-DNA) in maternal blood has the potential to dramatically alter the way prenatal screening and diagnosis is delivered. Before NIPT can be implemented into routine practice, information is required on its costs and benefits. The best performing screening tests are able to identify more than 90?% of trisomy 21 cases with a 5?% rate of false positives but positive screening results require confirmation with diagnostic testing, such as amniocentesis or chorionic villus sampling (CVS). However, both sampling procedures are invasive, and are associated with significant risks to the fetus and mother, including the potential loss of a healthy fetus. For this reason invasive prenatal diagnosis tests are currently performed only in high-risk pregnancies or in pregnancies with increased maternal age and/or a family history of inherited disease. Therefore, developing a reliable method for NIPD for fetal trisomy 21 is of critical importance in prenatal care and NIPT is able to identify 99?% of trisomy 21 cases with a 0.1?% rate of false positives. As first-line testing NIPT detects more Down’s syndrome cases, results in fewer procedure-related miscarriages and is more expensive than current screening. When NIPT uptake increases, NIPT will detect more trisomy 21 cases with a small increase in procedure-related miscarriages and costs. As first-line testing NIPT is likely to produce more favorable outcomes but at greater cost. Further research is needed to evaluate NIPT under real world conditions.     

A two-year experience of non-invasive prenatal testing (NIPT) at an urban tertiary medical center in South Korea

ObjectiveTo report our experience of implementing non-invasive prenatal testing (NIPT) in a tertiary urban academic medical center in South Korea.Materials and methodsAn observational retrospective study of singleton and twin pregnancies that underwent prenatal screening for fetal aneuploidy from July 2016 to April 2018 was conducted. Demographics of the study population electing NIPT versus those opting the integrated test were compared. We also assessed clinical significant factors influencing cfDNA fetal fraction in NIPT.ResultsAmong the 817 women who underwent serum screening tests during the study period, 490 women (60.0%) chose the integrated test while 327 women (40.0%) chose NIPT. Compared to the integrated test group, women in the NIPT group were older (mean age 34.7 ± 3.7 vs. 32.6 ± 3.4; p-value < 0.01), multiparous (47.1% vs. 39.8%; p-value = 0.046), and had higher rate of previous abortion history (28.4% vs. 21.6%; p-value = 0.033). A significant decrease in the number of invasive diagnostic tests was observed since the adoption of NIPT. The screen negative and positive rates of the integrated test group for fetal aneuploidy were 95.3% and 4.7%, respectively while those of the NIPT group were 95.9% and 1.2%, respectively. The rate of inadequate cfDNA fetal fraction was 3.0%. Low fetal fraction was associated with higher maternal age, body weight and BMI.ConclusionsThe implementation of NIPT has significantly affected the practice pattern of prenatal aneuploidy screening by replacing the integrated test and decreasing invasive diagnostic tests.     

无创产前检测进行染色体缺失或重复检测的临床应用价值

目的:探讨无创产前检测(NIPT)进行染色体缺失或重复检测的临床应用价值。方法:对传统产前筛查异常、既往有唐氏儿分娩史及高龄孕妇等3500例孕妇采集外周血,采用Illumina测序技术检测母体血浆胎儿游离DNA(cff DNA),分析胎儿性染色体及除21、13、18号染色体以外的其他常染色体信息,对NIPT阳性的孕妇进行遗传咨询,对其中自愿进行介入性产前诊断的,行染色体核型分析及染色体微阵列分析(CMA)进行验证。结果:3500例接受NIPT的病例中,检出32例常染色体异常(除外21、13、18号),其中有11例接受介入性产前诊断,染色体核型分析及CMA检测分别提示3例异常,符合率27.3%(3/11)。检出45例性染色体异常,其中有23例接受介入性产前诊断,染色体核型分析及CMA检测分别确诊12例异常,符合率52.2%(12/45)。结论:NIPT在预测胎儿性染色体异常及常染色体(除外21、13、18号)异常方面有一定的参考价值,但需要进行染色体核型分析和(或)CMA检测进行验证。     

Perinatal outcomes of prenatal cases testing positive for trisomy 9 by noninvasive prenatal testing

ObjectivesTo evaluate the performance of non-invasive prenatal testing (NIPT) for the detection of fetal trisomy 9 in prenatal screening and to investigate the prenatal appearances and genetic counseling of trisomy 9 fetuses.Materials and methodsThe ultrasonography information, laboratory detection and pregnancy outcome of 16 cases of single pregnancy with trisomy 9 identified by NIPT who received amniocentesis in our prenatal diagnosis center from January 2018 to December 2020 were retrospectively analyzed.ResultsAmong the 16 cases, 2 cases of trisomy 9, 3 cases of trisomy 9 mosaicism, 2 cases reporting of regions of homozygosity and 9 cases of false positive were diagnosed. Among the true positive cases, 4 cases showed abnormal ultrasonic finding: 3 cases terminated pregnancy and 1 case was lost to follow-up. Another 1 case was in utero fetal demise in the second trimester without structural abnormality, and 2 cases were normal live birth without developmental abnormalities. In the 9 cases with normal kayrotyping, 1 case had termination of pregnancy and 1 case with mental retardation and poor cognitive ability, other 7 had good pregnancy outcomes.ConclusionOur results may be helpful for the selection of prenatal diagnostic strategies and genetic counseling for pregnant women with trisomy 9 revealed by NIPT.     

妊娠早期胎儿颈部透明层厚度与胎儿预后的前瞻性队列研究

目的探讨妊娠早期胎儿颈部透明层(NT)厚度与胎儿预后的关系。方法收集2015年12月至2018年12月于南京大学医学院附属鼓楼医院行妊娠早期胎儿NT厚度测量的单胎孕妇,共4958例建立前瞻性研究队列,进行妊娠早期胎儿结构超声筛查、妊娠早期血清学筛查、妊娠中期超声筛查及对新生儿出生后28 d的体格检查。根据妊娠早期超声筛查的结果,分为胎儿NT增厚(≥3.0 mm)者167例与NT厚度正常者4791例;将胎儿NT增厚的孕妇,分为胎儿单纯NT增厚者86例与NT增厚合并结构异常者81例。分析不同NT厚度胎儿的预后,并重点对单纯NT增厚与NT增厚合并结构异常胎儿的妊娠结局进行分析。妊娠早期超声筛查发现胎儿结构异常或血清学筛查结果为高风险的孕妇,经绒毛穿刺取样术行染色体微阵列分析(CMA)检测以明确产前诊断。结果(1)胎儿NT厚度正常孕妇的妊娠结局:共4791例孕妇,包括胎儿NT厚度正常且无结构异常者4726例,其中妊娠中期及产后新诊断结构异常83例,4688例活产;胎儿NT厚度正常但结构异常的孕妇65例,其中61例孕妇终止妊娠,4例活产。(2)胎儿单纯NT增厚孕妇的妊娠结局:86例孕妇中,66例(76.7%,66/86)行CMA检测,3例胎儿诊断为21三体综合征;除7例孕妇选择终止妊娠外,余79例行妊娠中期超声检查、新生儿出生后28 d体格检查、新生儿电话随访至6~21个月均未发现发育异常。(3)胎儿NT增厚合并结构异常孕妇的妊娠结局:81例孕妇中,73例(90.1%,73/81)行CMA检测,其中32例的胎儿为染色体非整倍体异常。70例选择终止妊娠,2例妊娠中期自然流产,9例活产。(4)NT增厚是否合并结构异常胎儿的产前诊断结果及预后比较:单纯NT增厚的胎儿染色体非整倍体的发生率为3.5%(3/86),合并结构异常者为39.5%(32/81),两者比较,差异有统计学意义(χ2=32.7,P<0.01);胎儿单纯NT增厚孕妇的健康新生儿存活率为91.9%(79/86),合并结构异常者为9.9%(8/81),两者比较,差异有统计学意义(χ2=112.3,P<0.01)。结论妊娠早期,超声筛查胎儿NT及结构,能提高出生缺陷的产前筛查率。单纯NT增厚胎儿的染色体非整倍体的发生率较低,新生儿健康存活率较高。     

Prenatal persistent left superior vena cava in low population: Not a benign vascular anomaly

ObjectiveThe aim of this study is to identify prenatally diagnosed cases of persistent left superior vena cava (PLSVC) in our clinic, to evaluate the associated structural and chromosomal results, and to review their outcome.Materials and MethodsDuring a four-year period, patients with fetal PLSVC were detected by echocardiography. We reviewed medical records of these affected pregnancies, including maternal demographics, sonographic findings, chromosomal microarray results and pregnancy outcomes.ResultsThere were a total of 140 cases of fetal PLSVC. Eighty-nine fetuses (63.6%) had associated structural anomalies, while the remaining 51 fetuses (36.3%) had PLSVC as an isolated finding. In the non-isolated cases, cardiac anomalies were present in 72 fetuses (80.9%), and extracardiac abnormalities in 45 fetuses (50.6%). Among the 89 cases with non-isolated PLSVC, 12 cases had chromosomal abnormalities including 5 cases of aneuploidies. Among the 51 cases with isolated PLSVC, one pregnancy of chromosomal microduplication was detected.ConclusionIsolated PLSVC is a benign vascular anomaly in low risk population. However, the information about background risk of identifying an abnormal clinically significant CMA result should be conveyed to all pregnant women when they consults this vascular variation.     

3D ultrasound and Doppler angiography for evaluation of fetal cardiovascular anomalies

ObjectiveTo highlight the value of 3D ultrasound in the prenatal assessment of fetal cardiovascular anomalies through offline diagnosis and/or second opinion (e.g. via internet link).MethodsA retrospective offline analysis of volume datasets of fetuses diagnosed with cardiovascular anomalies by 2D ultrasound was conducted.ResultsThirty-three fetuses with 38 cardiac malformations were evaluated. Mean gestational age at diagnosis was 26 weeks (range, 20–34 weeks). Isolated cardiovascular malformations were detected in 23 fetuses. Extracardiac abnormalities were identified in 8 fetuses, of which 2 had trisomy 21 and 1 had trisomy 18. One fetus exhibited 22q11 microdeletion. Ten pregnancy terminations were performed.ConclusionOffline analysis of cardiovascular anomalies conferred significant diagnostic advantages over 2D ultrasound. 3D ultrasound is invaluable for the prenatal diagnosis and management of congenital heart diseases. It may be used to facilitate scientific cooperation between high- and low-income countries.     

Ultrasound diagnosis of fetal abnormalities and cytogenetic evaluation.

Over a 6 1/2 year period, in 288 pregnancies a variety of fetal malformations were detected by ultrasound. Two hundred and ten fetuses (73 per cent) were karyotyped. Gestational age at detection ranged from 11 to 38 weeks. The incidence of an abnormal karyotype in the total series was 14 per cent and 14.7 per cent in the 210 pregnancies in which a karyotype was performed. Single structural anomalies were found in 149 cytogenetically investigated fetuses, of which 25 had a chromosomal abnormality (17 per cent). Multiple structural malformations were present in 61 fetuses, of which 16 had an abnormal karyotype (26 per cent). Trisomy 18 was the most frequent finding. The most constant ultrasound finding in cases of an abnormal karyotype was polyhydramnios and severe IUGR in combination with structural defects. There is a need for extensive detailed ultrasound examination in high-risk pregnancies.     

Fetal aneuploidy screening with cell-free DNA in late gestation

Objective: The aim of this study was to evaluate clinical use of NIPT at gestational ages of 23 weeks and above.

Methods: A cohort of 5579 clinical patients with singleton gestations of 23 weeks or greater submitting a blood sample for NIPT in an 18-month period were selected for this study. Clinical outcomes were requested for samples with NIPT results indicating fetal aneuploidy and compared with NIPT findings to confirm concordance or discordance.

Results: A review of clinical indications revealed that a significantly (p?Conclusions: NIPT is a highly accurate prenatal screening option for women after 23 weeks of gestation. Women who presented for NIPT in the latter stages of pregnancy more frequently specified clinical indications of abnormal ultrasound findings than women who entered screening earlier in pregnancy.