Invasive Prenatal Diagnostic Testing Research Articles

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

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. 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. 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. 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. IPDT is important in correctly diagnosing fetal anomalies at the prenatal stage to help families decide at the right time.

Value of non-invasive prenatal testing for rare autosomal trisomies in fetuses

To evaluate the value of non-invasive prenatal testing(NIPT)for detecting rare autosomal trisomies in fetuses. We retrospectively analyzed the data of cases with rare autosomal trisomies detected by NIPT in our hospital from January, 2019 to April, 2023.Invasive prenatal diagnostic tests including chromosome karyotype analysis, chromosome microarray analysis, copy number variation sequencing, and fluorescence in situ hybridization were performed in all the cases after clinical counseling, and their test results and pregnancy outcomes were analyzed. Among 25 282 women receiving NIPT, 56(0.22%)were found to have high risks for rare autosomal trisomies in circulating plasma DNA.Trisomy 7 was the most frequently detected trisomy, accounting for 45% of the total cases(25/56), while trisomies 1, 4, 17, and 19 were not detected.Among the 46 cases with genetic results of the fetuses, 10 were identified to have true fetal mosaicism.The overall positive predictive value of NIPT was 22%(10/46)for rare autosomal trisomies, and 10% for trisomy 7(2/20).Of the 52 cases followed up for pregnancy outcomes, 33(63%)cases without fetal mosaicism resulted in normal live births, while 10 had unfavorable outcomes including fetal growth restriction, preterm birth, and maternal complications, and among them fetal growth restriction was the most typical and the earliest condition observed in these cases.Among the 22 followed up cases of non-true mosaicism for trisomy 7, 82% resulted in normal live births. NIPT increases the detection rate of true fetal mosaicism but with a low positive predictive value.Most of the cases with non-true mosaicism, particularly trisomy 7, can have favorable outcomes.NIPT can also be useful in identifying causes of fetal growth restriction in the second and third trimesters when invasive prenatal testing does not reveal abnormalities.

Results of karyotype analysis and 22q11.2 (DiGeorge Syndrome critical region) deletion investigation in fetal cardiac system anomalies

The results of karyotype analysis and 22q11.2 ( DiGeorge Syndrome critical region) deletion investigation in fetal cardiac system anomalies 
 Objective: We aimed to determine the presence of accompanying chromosomal anomalies and 22q11.2 deletion in patients with cardiac system anomalies.
 Material and Methods: In our retrospective and cross-sectional study, 99 fetuses born with cardiac anomalies were evaluated in terms of chromosomal anomalies. 36 fetuses were evaluated for 22q11.2 deletion. Fetuses who were diagnosed with prenatal congenital heart defect and underwent invasive prenatal diagnostic tests for fetal karyotyping between 01.01.2010 and 30.06.2017 at a tertiary cancer center were included in the study.
 Results: Of 99 cases, 48 (48.4%) had only cardiac anomalies and 51 (51.5%) had non-cardiac anomalies. Chromosomal anomalies were found in 37 (37.4%) of the cases. Autosomal trisomy 18(43.2%) and autosomal trisomy 21(32.4%) were the most common chromosomal anomalies. The study results support the strong association of chromosomal changes and cardiac malformation, especially in septal defects, atrioventricular septal defects, and conotruncal malformations. Deletion was detected in one(2.8%) of 36 cases evaluated for 22q11.2 deletion. The fetus with this deletion had isolated tetralogy of fallot and had no extracardiac anomaly.
 Conclusion: In cases with cardiac anomalies, isolated or accompanied by extracardiac anomalies, investigations should be made in terms of underlying chromosomal diseases in the perinatal evaluation. In addition, the investigation of 22q11.2 deletion in fetuses with conotruncal cardiac anomalies should be included in prenatal genetic examination.
 Keywords: DiGeorge Syndrome, Fetal Anomalies, karyotype, trisomy, 22q11.2 Deletion Syndrome

Incidence of sex chromosome aneuploidy in a prenatal population: 27-year longitudinal study in Northern Italy.

The availability of cell-free (cf) DNA as a prenatal screening tool affords an opportunity for non-invasive identification of sex chromosome aneuploidy (SCA). The aims of this longitudinal study were to investigate the evolution and frequency of both invasive prenatal diagnostic testing, using amniocentesis and chorionic villus sampling (CVS), and the detection of SCA in cfDNA samples from a large unselected cohort in Northern Italy. The results of genetic testing from CVS and amniotic fluid samples received from public and private centers in Italy from 1995 to 2021 were collected. Chromosomal analysis was performed by routine Q-banding karyotype. Regression analyses and descriptive statistics were used to determine population data trends regarding the frequency of prenatal diagnostic testing and the identification of SCA, and these were compared with the changes in indication for prenatal diagnostic tests and available screening options. Over a period of 27 years, there were 13 939 526 recorded births and 231 227 invasive procedures were performed, resulting in the prenatal diagnosis of 933 SCAs. After the commercial introduction of cfDNA use in 2015, the frequency of invasive procedures decreased significantly (P = 0.03), while the frequency of prenatal SCA detection increased significantly (P = 0.007). Between 2016 and 2021, a high-risk cfDNA result was the indication for 31.4% of detected sex chromosome trisomies, second only to advanced maternal age. Our findings suggest that the inclusion of SCA in prenatal cfDNA screening tests can increase the prenatal diagnosis of affected individuals. As the benefits of early ascertainment are increasingly recognized, it is essential that healthcare providers are equipped with comprehensive and evidence-based information regarding the associated phenotypic differences and the availability of targeted effective interventions to improve neurodevelopmental and health outcomes for affected individuals. © 2023 International Society of Ultrasound in Obstetrics and Gynecology.

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.

Prenatal Diagnosis and Pregnancy Outcomes of Fetuses With Orofacial Cleft: A Retrospective Cohort Study in Two Centres in Hong Kong.

To evaluate the local incidence of orofacial cleft (OFC) encountered in fetal morphology scan and prenatal diagnosis, genetic etiology of fetuses with or without other structural abnormalities, and their pregnancy outcomes. Retrospective cohort study. Two maternal fetal medicine units, tertiary hospitals, Hong Kong. All pregnant women with antenatal diagnosis of fetal OFC between January 2016 and December 2020 (N = 66). OFC has an incidence of 0.13% among pregnancies in Hong Kong and 28.8% (19/66) were syndromic cleft that exhibited other fetal structural anomalies. There were 55 cases (84.6%) who opted for invasive prenatal diagnostic testing. Genetic defects were identified in 25.8% (17/66) of this cohort, including 14 pathogenic variants. The detection rate in the syndromic cases is 68.4% (13/19) which was significantly higher than 8.5% (4/47) among non-syndromic cases. Aneuploidies would be the most common cause, accounting for 9.1% (6/66). Chromosomal microarray analysis (CMA) provided an incremental diagnostic yield of 6.1% compared to conventional karyotyping. A total of 29 live births including 3 cases of a variant of uncertain significance and 26 cases without genetic abnormalities detected have continued pregnancy to birth. There were 87.5% (21/24) without detectable pathogenic genetic abnormality reported good long-term outcomes. The chance of OFC fetuses having a good long-term outcome was significantly higher if no genomic variant was detected (P < .001). Invasive prenatal tests with CMA should be offered to pregnancies with OFC regardless of the type. It has provided incremental diagnostic yield over conventional karyotyping and helped in prenatal and genetic counseling. A negative result in non-syndromic OFC favors couples to keep the pregnancy.

Prenatal diagnosis of cystic hygroma cases in a tertiary centre and retrospective analysis of pregnancy results

The aim of this study is to retrospectively examine invasive diagnostic methods, structural anomalies accompanying cystic hygroma, and pregnancy outcomes in cystic hygroma cases admitted to a tertiary centre. The population of the study consisted of 29 live foetuses with cystic hygroma in the foetal neck only in the first or second trimester. In the study, pregnant women who applied to our centre were included. Amniocentesis or chorionic villus sampling was performed for genetic analysis according to the weeks of the pregnant women who were diagnosed with cystic hygroma by ultrasound examination by two clinicians experienced in foetal anomaly. Of the pregnant women included in the study, 10 had normal karyotype, 12 had abnormal karyotype and 13 had structural abnormality. It is very important to provide genetic counselling to the families of foetuses with cystic hygroma with a multidisciplinary team approach consisting of neonatologists, paediatric surgeons and experienced sonographers. Implications for rehabilitation What is already known on this subject? Cystic hygroma, also known as cystic lymphangioma, is a congenital cystic malformation often seen in the first trimester, which occurs in the foetal neck due to the failure of the connections between the cervical lymphatic vessels and the jugular venous system to develop normally. Cystic hygroma may be isolated, but highly associated with foetal aneuploidy, hydrops fetalis, abnormal foetal nuchal translucency. What do the results of this study add? Invasive prenatal diagnostic tests (CVS or amniocentesis) should be performed in all patients with cystic hygroma, as cystic hygromas can be diagnosed by first trimester foetal genetic sonogram screening and are largely accompanied by chromosomal abnormalities. What are the implications of these findings for clinical practice and/or further research? In foetuses with cystic hygroma, foetal karyotyping, detailed sonography and their documentation, genetic counselling is important to families of cystic hygroma foetuses with a multidisciplinary team approach consisting of neonatologists, paediatric surgeons and maternal foetal medicine specialists, since there is a high risk for aneuploidy and foetal malformation.

Non-invasive prenatal testing in mitigating concerns from invasive prenatal diagnostic testing: retrospective assessment of utility in an academic healthcare system in the US

ObjectiveNon-invasive prenatal testing (NIPT) is a front-line screening for fatal chromosomal aneuploidy. In pregnant women with a risk of having fetal congenital disorders, NIPT is anticipated to reduce the needs...

The impact of preimplantation genetic testing for aneuploidy on prenatal screening.

To determine whether preimplantation genetic testing for aneuploidy (PGT-A) is associated with a reduced risk of abnormal conventional prenatal screening results in singleton pregnancies conceived using in vitro fertilization (IVF). This was a retrospective cohort study of singleton IVF pregnancies conceived from a single tertiary care center between January 2014 and September 2019. Exclusion criteria included mosaic embryo transfers, vanishing twin pregnancies, and cycles with missing outcome data. Two cases of prenatally diagnosed aneuploidy that resulted in early voluntary terminations were also excluded. The primary outcome of abnormal first or second-trimester combined screening results was compared between two groups: pregnancy conceived after transfer of a euploid embryo by PGT-A vs. transfer of an untested embryo. Multivariable backwards-stepwise logistic regression with Firth method was used to adjust for potential confounders. Of the 419 pregnancies included, 208 (49.6%) were conceived after transfer of a euploid embryo by PGT-A, and 211 (50.4%) were conceived after transfer of an untested embryo. PGT-A was not associated with a lower likelihood of abnormal first-trimester (adjusted OR 1.64, 95% CI 0.82-3.39) or second-trimester screening results (adjusted OR 0.96, 95% CI 0.56-1.64). The incidences of cell-free DNA testing, fetal sonographic abnormalities, genetic counseling, and invasive prenatal diagnostic testing were similar between the two groups. Our data suggest that PGT-A is not associated with a change in the likelihood of abnormal prenatal screening results or utilization of invasive prenatal diagnostic testing. Counseling this patient population regarding the importance of prenatal screening and prenatal diagnostic testing, where appropriate, remains essential.

Performance of a universal prenatal screening program incorporating cell-free fetal DNA analysis in Ontario, Canada.

BACKGROUND:The emergence of cell-free fetal DNA (cfDNA) testing technology has disrupted the landscape of prenatal screening for trisomies 21 (T21) and 18 (T18). Publicly funded systems around the world are grappling with how to best integrate this more accurate but costly technology, as there is limited evidence about its incremental value in real-world conditions. The objectives of this study were to describe the population-based performance of Ontario’s prenatal screening program, which incorporates publicly funded cfDNA screening for specific indications, and the effect of cfDNA testing on the screening and diagnostic choices made by pregnant people.METHODS:We conducted a retrospective, descriptive cohort study using routinely collected data from Better Outcomes & Registry Network (BORN) Ontario, which captures linked population data for prenatal and neonatal health encounters across Ontario. We included all singleton pregnancies with an estimated due date between Sept. 1, 2016, and Mar. 31, 2019, that underwent publicly funded prenatal screening in Ontario, and a comparison cohort from Apr. 1, 2012, and Mar. 31, 2013. We assessed performance of the screening program for the detection of T21 or T18 by calculating sensitivity, specificity, positive predictive value and negative predictive value against diagnostic cytogenetic results or birth outcomes. We assessed the impact of the program by calculating the proportion of T21 screen-positive pregnancies undergoing subsequent cfDNA screening and invasive prenatal diagnostic testing.RESULTS:The study cohort included 373 682 pregnancies. The prenatal screening program had an uptake of 69.9%, a screen-positive rate and sensitivity of 1.6% and 89.9% for T21, and 0.2% and 80.5% for T18, respectively. The test failure rate for cfDNA screening was 2.2%. Invasive prenatal diagnostic testing decreased from 4.4% in 2012–2013 to 2.4% over the study period; 65.2% of pregnant people who received a screen-positive result from cfDNA testing went on to have invasive prenatal diagnostic testing.INTERPRETATION:This publicly funded screening program, incorporating cfDNA analysis for common aneuploidies, showed robust performance, a substantial reduction in invasive prenatal diagnostic testing and that pregnant people exercise autonomy in their choices about prenatal screening and diagnosis.

918 The impact of preimplantation genetic testing for aneuploidy on prenatal screening

The clinical utility of preimplantation genetic testing for aneuploidy (PGT-A) is well established. However, data is limited on the residual risk for abnormal prenatal screening in PGT-A screened embryos. We investigated whether PGT-A is associated with a reduced risk of abnormal prenatal screening in singleton pregnancies conceived using in vitro fertilization (IVF). Retrospective cohort of singleton IVF pregnancies conceived from a single center from 01/2014 to 09/2019. Exclusion criteria included transfer of mosaic embryos, vanishing twins, and missing data. Two cases of prenatally diagnosed aneuploidy that resulted in early voluntary terminations were also excluded. Maternal age was adjusted for donor egg age where indicated. The primary outcome of abnormal first or second trimester serum screening was compared between two groups: pregnancy after transfer of a euploid embryo by PGT-A (n = 208) versus transfer of an untested embryo (n = 211). Secondary outcomes included other prenatal screening modalities and rate of invasive prenatal diagnostic testing. Multivariate backwards-stepwise logistic regression with Firth method was used to adjust for potential confounders. Baseline characteristics compared between the two groups are displayed in Table 1. PGT-A was not associated with a reduced risk of abnormal first-trimester (adjusted OR 1.64, 95% CI 0.82-3.39) or second-trimester screening (adjusted OR 0.96, 95% CI 0.56-1.64) (Table 2). The likelihood of cell free DNA testing, soft sonographic markers, major fetal structural malformations, genetic counseling and invasive prenatal diagnostic testing were also similar between the two groups (Table 2). Our data illustrate that PGT-A is not associated with a reduced rate of abnormal prenatal screening, or likelihood of invasive prenatal diagnostic testing. Nevertheless, counseling this patient population regarding the importance of prenatal screening and prenatal diagnostic testing where appropriate remains essential.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

Noninvasive prenatal testing for assessing foetal sex chromosome aneuploidy: a retrospective study of 45,773 cases

ObjectiveTo assess the positive predictive value (PPV) of noninvasive prenatal testing (NIPT) as a screening test for sex chromosome aneuploidy (SCA) with different maternal characteristics and prenatal decisions in positive cases.Materials and methodsWe retrospectively analysed 45,773 singleton pregnancies with different characteristics that were subjected to NIPT in the Maternity and Child Health Hospital of Anhui Province. The results were validated by karyotyping. Clinical data, diagnostic results, and data on pregnancy outcomes were collected.ResultsIn total, 314 cases were SCA positive by NIPT; among those, 143 underwent invasive prenatal diagnostic testing, and 58 were true-positive. Overall, the PPVs for 45,X, 47,XXX, 47,XXY and 47,XYY were 12.5%, 51.72%, 66.67% and 83.33%, respectively. Interestingly, when only pregnant women of advanced maternal age (AMA) were screened, the PPVs for 45,X, 47,XXX, 47,XXY and 47,XYY were 23.81%, 53.33%, 78.95%, and 66.67%, respectively. The frequency of SCA was significantly higher in the AMA group than in the non-AMA group. The frequencies of 47,XXX and 47,XXY were significantly correlated with maternal age.ConclusionNIPT performed better in predicting sex chromosome trisomies than monosomy X, and patients with 45,X positive foetuses were more eager to terminate pregnancy than those with 47,XXX and 47,XYY. AMA may be a risk factor of having a foetus with SCA. Our findings may assist in genetic counselling of AMA pregnant women. Our pre- and posttest counselling are essential for familiarizing pregnant women with the benefits and limitations of NIPT, which may ease their anxiety and enable them to make informed choices for further diagnosis and pregnancy decisions.

Clinical Practice Guidelines for Prenatal Aneuploidy Screening and Diagnostic Testing from Korean Society of Maternal-Fetal Medicine: (2) Invasive Diagnostic Testing for Fetal Chromosomal Abnormalities.

The Korean Society of Maternal Fetal Medicine proposed the first Korean guideline on prenatal aneuploidy screening and diagnostic testing, in April 2019. The clinical practice guideline (CPG) was developed for Korean women using an adaptation process based on good-quality practice guidelines, previously developed in other countries, on prenatal screening and invasive diagnostic testing for fetal chromosome abnormalities. We reviewed current guidelines and developed a Korean CPG on invasive diagnostic testing for fetal chromosome abnormalities according to the adaptation process. Recommendations for selected 11 key questions are: 1) Considering the increased risk of fetal loss in invasive prenatal diagnostic testing for fetal genetic disorders, it is not recommended for all pregnant women aged over 35 years. 2) Because early amniocentesis performed before 14 weeks of pregnancy increases the risk of fetal loss and malformation, chorionic villus sampling (CVS) is recommended for pregnant women who will undergo invasive prenatal diagnostic testing for fetal genetic disorders in the first trimester of pregnancy. However, CVS before 9 weeks of pregnancy also increases the risk of fetal loss and deformity. Thus, CVS is recommended after 9 weeks of pregnancy. 3) Amniocentesis is recommended to distinguish true fetal mosaicism from confined placental mosaicism. 4) Anti-immunoglobulin should be administered within 72 hours after the invasive diagnostic testing. 5) Since there is a high risk of vertical transmission, an invasive prenatal diagnostic testing is recommended according to the clinician's discretion with consideration of the condition of the pregnant woman. 6) The use of antibiotics is not recommended before or after an invasive diagnostic testing. 7) The chromosomal microarray test as an alternative to the conventional cytogenetic test is not recommended for all pregnant women who will undergo an invasive diagnostic testing. 8) Amniocentesis before 14 weeks of gestation is not recommended because it increases the risk of fetal loss and malformation. 9) CVS before 9 weeks of gestation is not recommended because it increases the risk of fetal loss and malformation. 10) Although the risk of fetal loss associated with invasive prenatal diagnostic testing (amniocentesis and CVS) may vary based on the proficiency of the operator, the risk of fetal loss due to invasive prenatal diagnostic testing is higher in twin pregnancies than in singleton pregnancies. 11) When a monochorionic twin is identified in early pregnancy and the growth and structure of both fetuses are consistent, an invasive prenatal diagnostic testing can be performed on one fetus alone. However, an invasive prenatal diagnostic testing is recommended for each fetus in cases of pregnancy conceived via in vitro fertilization, or in cases in which the growth of both fetuses differs, or in those in which at least one fetus has a structural abnormality. The guidelines were established and approved by the Korean Academy of Medical Sciences. This guideline is revised and presented every 5 years.

First Trimester Screening for Common Trisomies and Microdeletion 22q11.2 Syndrome Using Cell-Free DNA: A Prospective Clinical Study

Objectives: The aims of the study were to assess the false-positive and uninformative test rate with first trimester cell-free DNA (cfDNA) screening for common trisomies and microdeletion 22q11.2 (22q11.2DS) and to examine women’s attitudes toward such an approach. Methods: This is a prospective study at the Prenatal Medicine Department of the University of Tübingen, Germany, at 11–13 weeks. In all pregnancies, a detailed ultrasound examination was carried out, followed by a cfDNA analysis for common trisomies and 22q11.2DS. In cases where the cfDNA analysis indicated 22q11.2DS, invasive prenatal diagnostic testing and parental testing were performed. After delivery, a detailed neonatal clinical examination was carried out including further genetic testing. Prior to counselling about the study, we asked the pregnant women who were potentially eligible for the study to anonymously report on their knowledge about 22q11.2DS. Results: A total of 1,127 pregnancies were included in the final analysis of the study. The first cfDNA test was uninformative in 15 (1.33%) pregnancies. In 10 (0.89%) cases, the test remained uninformative, even after the second blood sample. There were 3 (0.27%) cases with a positive cfDNA test for 22q11.2DS. In all, 983 women returned the anonymous questionnaire prior to study participation. Only 80 (8.1%) women responded that they felt familiar or very familiar with 22q11.2DS. Conclusion: The addition of 22q11.2DS in first trimester cfDNA screening for common trisomies is feasible. The uninformative test rate for common trisomies and 22q11.2DS is 0.9%, and the false-positive rate for 22q11.2DS is 0.3%. Awareness and education around 22q11.2DS should be improved.

Chromosome microarray analysis should be offered to all invasive prenatal diagnostic testing following a normal rapid aneuploidy test result.

Chromosomal microarray analysis (CMA) has now replaced karyotyping in the analysis of prenatal cases with a fetal structural anomaly, whereas in those pregnancies undergoing invasive prenatal diagnosis with a normal fetal ultrasound, conventional karyotyping is still performed. The aims of this study were to establish the diagnostic yield of CMA in prenatal diagnosis, and to provide new data that might contribute to reconsider current practices. We reviewed 2905 prenatal samples with a normal rapid aneuploidy detection test referred for evaluation by CMA testing. Our study revealed pathogenic and reported susceptibility copy number variants associated with syndromic disorders in 4.8% (n = 138/2905) of cases, being 2.8% (n = 81/2905) the estimated added diagnostic value of CMA over karyotyping. Clinically significant CMA abnormality was detected in 5.4% (107/1975) of the fetuses with ultrasound anomalies and in 1.4% (5/345) of those considered as low-risk pregnancies. Our series shows that in prenatal samples, CMA increases 2-fold the diagnostic yield achieved by conventional karyotyping.

Comparison of indications and results of prenatal invasive diagnostic tests before and after the implementation of the use of cell-free fetal DNA: a tertiary referral center experience.

In this study, we aimed to compare the changes in the number, yield, and the percentage of karyotyping indications of the invasive prenatal diagnostic tests between the periods before and after cell-free fetal DNA was introduced to clinical use. The number of invasive prenatal diagnostic procedures such as amniocentesis and chorionic villus sampling, indication percentages and karyotype results in the periods before (January 1, 2009-December 31, 2010), (n = 1412) and after (January 1, 2016-December 31, 2017), and (n = 593) the introduction of cell-free fetal DNA was retrospectively evaluated. When compared with the period before cell-free fetal DNA came into clinical use, the number of invasive prenatal diagnostic tests decreased by 58% while their yield was found to have increased (4.4% vs. 10.3%) in the period after cell-free DNA began to be used (p < 0.001). While there was a decrease in the indications due to advanced maternal age, an increase was found in ultrasonography indications for structural anomaly and the risk of a single-gene disorder (p < 0.001). Amniocentesis rate was found to have decreased in invasive prenatal diagnostic procedure types, while an increase was reported in CVS rates (p < 0.001). Invasive prenatal diagnosis gradually decreases over the years, but the yield of invasive prenatal diagnostic tests increases. In parallel with the rapid development of modern molecular technologies and cheaper and easier access to the tests, we think that the number of invasive prenatal diagnostic tests will experience a more dramatic decrease in the following years.

Concerns of Pregnant Women in “Prenatal Screening/Diagnosis” Practice and Termination of Pregnancy

To investigate the reasons for decision-making and concerns of patients in the field of prenatal screening, invasive prenatal diagnostic testing (IPDT), and termination of pregnancy (TOP). This questionnaire-based study consisted of 107 pregnant women who were referred for prenatal screening to the Hacettepe University Hospital. The questionnaire given to patients was prepared from scratch since there is no standard set of questions measuring patients' feelings and concerns regarding prenatal screening/diagnosis, IPDT, and TOP. Our questionnaire results showed that it is possible to classify decision-making factors into 6 groups: psychological, social, fear, religious/faith, support, and trust. The majority of patients were undecided (48.6%) about IPDT if prenatal screening test results were risky. Only 23.4% of patients were willing to accept IPDT. On the other hand, 55.1% of patients were not willing to undergo TOP if the fetal karyotyping results were abnormal. Religious factors seem to be important in refusing IPDT and TOP. Physicians should re-evaluate their practice in the field of prenatal screening and diagnosis in light of the high refusal rates of IPDT and TOP. Understanding factors influencing women's decision-making processes provides insight for service providers to help women at high risk of having foetal anomalies to make better-informed choices.

The impact of invasive prenatal testing on anxiety and sleep quality in pregnant women with a screen-positive result for aneuploidy

Purpose Prenatal anxiety has negative effects on pregnancy and neonate. Both screening tests and invasive diagnostic tests are associated with elevated anxiety level. But a normal fetal karyotype result could improve the anxiety level in high-risk patients. We hypothesized that patients who prefer follow-up without karyotyping may experience increased anxiety and sleep impairment until delivery. Our aim was to determine the effect of invasive diagnostic test decision on anxiety and sleep quality in women with a positive screening result. Methods 132 women were included for the study and three groups were described. The invasive group consisted of women who underwent invasive procedure after a screen-positive test result, the follow-up group consisted of women who preferred non-invasive follow-up after a screen-positive result and the control group consisted of women with screen-negative test results. Participants were evaluated with the State-Trait Anxiety Inventory (STAI) and the Pittsburgh Sleep Quality Index (PSQI) after genetic counseling. They were asked for completing the same questionnaires in the third trimester to establish the course of anxiety and sleep quality throughout pregnancy. Results STAI scores were significantly higher in both screen-positive groups than in the control group in the first evaluation (p < 0.001). STAI scores decreased in the invasive group and controls while PSQI scores did not significantly change during the course of the pregnancy. However, the anxiety level and sleep quality were worsened over time in the follow-up group. Conclusion Screen-positive women who preferred to follow up had higher anxiety level and worse sleep quality in the later stages of pregnancy. We concluded that invasive prenatal diagnostic tests could improve anxiety and sleep quality in pregnant women with a screen-positive result for aneuploidy.

The impact of preimplantation genetic testing on prenatal diagnostic procedures

Objective In recent years, cell-free DNA screening has significantly reduced the number of invasive prenatal diagnostic testing in pregnancy. Preimplantation genetic testing for aneuploidies (PGT-A) is a commonly performed screening test in in vitro fertilization (IVF) pregnancies. Therefore, we aimed to determine the impact of PGT-A on subsequent utilization of prenatal diagnostic testing in IVF pregnancies. Methods Retrospective cohort of singleton and twin IVF pregnancies at a single center from January 2014 to December 2017. The rate of invasive diagnostic genetic testing (chorionic villus sampling (CVS) and/or amniocentesis) was compared between patients with pregnancies achieved after transfer of a euploid embryo by PGT-A (n = 71) and those with pregnancies achieved after transfer of an untested embryo (n = 38). Wilcoxon rank sum and Fisher’s exact tests were used for statistical analysis. Results There was no statistically significant difference in the number of prenatal diagnostic procedures (25.4% PGT-A euploid embryo versus 31.6% untested embryo, p = .51 and p = .32 for one-sided and two-sided analyses, respectively) between the two groups. Maternal age, nuchal translucency measurements and the rate of abnormal sonographic findings were similar between the two groups. Patients without PGT-A pregnancies had a higher BMI (mean 29.6, p = .01) and were ethnically different (p = .013) compared to those with PGT-A. Conclusion The implementation of PGT-A in IVF patients did not reduce the number of invasive diagnostic tests performed at our institution.

Characteristics and mode of inheritance of pathogenic copy number variants in prenatal diagnosis

Microdeletions and microduplications can occur in any pregnancy independent of maternal age. The spectrum and features of pathogenic copy number variants including the size, genomic distribution, and mode of inheritance are not well studied. These characteristics have important clinical implications regarding expanding noninvasive prenatal screening for microdeletions and microduplications. The aim was to investigate the spectrum and characteristics of pathogenic copy number variants in prenatal genetic diagnosis and to provide recommendations for expanding the scope of noninvasive prenatal screening for microdeletions and microduplications. This was a retrospective study of 1510 pregnant women who underwent invasive prenatal diagnostic testing by chromosomal microarray analysis. Prenatal samples were retrieved by amniocentesis or chorionic villus sampling and sent to our prenatal genetic diagnosis laboratory for chromosomal microarray analysis. The risk of carrying a fetus with pathogenic copy number variants is stratified by the patients' primary indication for invasive testing. We searched the literature for published prenatal chromosomal microarray data to generate a large cohort of 23,865 fetuses. The characteristics and spectrum of pathogenic copy number variants including the type of aberrations (gains or losses), genomic loci, sizes, and the mode of inheritance were studied. Overall, 375 of 23,865 fetuses (1.6%) carried pathogenic copy number variants for any indication for invasive testing, and 44 of them (11.7%) involve 2 or more pathogenic copy number variants. A total of 428 pathogenic copy number variants were detected in these fetuses, of which 280 were deletions and 148 were duplications. Three hundred sixty (84.1%) were less than 5 Mb in size and 68 (15.9%) were between 5 and 10 Mb. The incidence of carrying a pathogenic copy number variant in the high-risk group is 1 in 36 and the low-risk group is 1 in 125. Parental inheritance study results were available for 311 pathogenic copy number variants, 71 (22.8%) were maternally inherited, 36 (11.6%) were paternally inherited, and 204 (65.6%) occurred de novo. Collectively, pathogenic copy number variants are common in pregnancies. High-risk pregnancies should be offered invasive testing with chromosomal microarray analysis for the most comprehensive investigation. Detection limits on size, parental inheritance, and genomic distribution should be carefully considered before implementing copy number variant screening in expanded noninvasive prenatal screening.