ISUOG Practice Guidelines: invasive procedures for prenatal diagnosis

Predictive Prenatal Diagnosis for Infantile-onset Inflammatory Bowel Disease Because of Interleukin-10 Signalling Defects

OBJECTIVES

Advances in genetic technologies provide opportunities for patient care and ethical challenges. Clinical care of patients with rare Mendelian disorders is often at the forefront of those developments. Whereas in classical polygenic inflammatory bowel disease (IBD), the predictive value of genetic variants is very low, predictive prenatal genetic diagnosis can inform families at high risk of severe genetic disorders. Patients with IL-10 signalling defects because of pathogenic variants in IL10RA, Il10RB, and IL10 develop severe infantile onset inflammatory bowel disease that is completely penetrant and has a high morbidity and substantial mortality despite treatment.

METHODS

We performed a survey among tertiary specialist paediatric centers of 10 countries on the utilization of predictive prenatal genetic diagnosis in IL-10 signalling defects. We retrospectively report prenatal genetics in a series of 8 families.

RESULTS

International variation in legislation, guidelines, expert opinion, as well as cultural and religious background of families and clinicians results in variable utilization of preimplantation and prenatal genetic testing for IL-10 signalling defects. Eleven referrals for prenatal diagnosis for IL-10 signalling defects were identified across 4 countries. We report on 8 families who underwent prenatal preimplantation monogenic testing after in vitro fertilization (n = 2) and/or by amniocentesis/chorion villus sampling (n = 6). A genetic diagnosis was established in 1 foetus and excluded in 7 foetuses (all IL10RA variants).

CONCLUSIONS

Prenatal genetic testing for IL10R-defects is feasible, yet the legal and ethical considerations are complex and controversial. In some countries, predictive genetics for IL-10-related signalling defects is entering clinical practice.

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.

Prenatal Diagnosis for Primary Immunodeficiency Disorders-An Overview of the Indian Scenario

Prenatal Diagnosis (PND) forms an important part of primary preventive management for families having a child affected with primary immunodeficiency. Although individually sparse, collectively this group of genetic disorders represents a significant burden of disease. This paper discusses the prenatal services available for affected families at various centers across the country and the challenges and ethical considerations associated with genetic counseling. Mutation detection in the index case and analysis of chorionic villous sampling or amniocentesis remain the preferred procedures for PND and phenotypic analysis of cordocentesis sample is reserved for families with well-characterized index case seeking PND in the latter part of the second trimester of pregnancy. A total of 112 families were provided PND services in the last decade and the presence of an affected fetus was confirmed in 32 families. Post-test genetic counseling enabled the affected families to make an informed decision about the current pregnancy.

Prenatal screening diagnosis and management in the era of coronavirus: the Sardinian experience

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a new coronavirus, was first identified in December 2019 in Wuhan, China and spread rapidly, affecting many other countries. The disease is now referred to as coronavirus disease 2019 (COVID-19).The Italian government declared a state of emergency on 31st January 2020 and on 11th March World Health Organization (WHO) officially declared the COVID-19 outbreak a global pandemic. Although the COVID-19 incidence remained considerably lower in Sardinia than in the North Italy regions, which were the most affected, the field of prenatal screening and diagnosis was modified because of the emerging pandemic. Data on COVID-19 during pregnancy are so far limited. Since the beginning of the emergency, our Ob/Gyn Department at Microcitemico Hospital, Cagliari offered to pregnant patients all procedures considered essential by the Italian Ministry of Health. To evaluate the influence of the COVID-19 pandemic on the activities of our center, we compared the number of procedures performed from 10th March to 18th May 2020 with those of 2019. Despite the continuous local birth rate decline, during the 10-week pandemic period, we registered a 20% increment of 1st trimester combined screening and a slight rise of the number of invasive prenatal procedures with a further increase in chorionic villi sampling compared to amniocentesis. Noninvasive prenatal testing remained unvariated. The request for multifetal pregnancy reduction as a part of the growing tendency of voluntary termination of pregnancy in Sardinia increased. The COVID-19 pandemic provides many scientific opportunities for clinical research and study of psychological and ethical issues in pregnant women.

Cell-free DNA Testing in Routine Practice: Characterisation of a Cohort with Positive Results for Trisomies, Sex Chromosome Anomalies and Microdeletions

Introduction Cell-free DNA (cfDNA) testing is increasingly used as a screening method not only for trisomy (T) 21 but also for T18 and T13, sex chromosome anomalies (SCA) and microdeletions. Based on cases with a positive cfDNA result in our specialised prenatal practice, this study aims to characterise the usage of cfDNA testing and to estimate the positive predictive value (PPV) in routine practice in Germany.

Patients and Methods In this retrospective study we analysed the data of all pregnant women with a positive cfDNA result seen between 09/2013 and 12/2019. Women were either referred due to the positive result or the test was initiated in our practice. The primary parameter of interest was the concordance of cfDNA tests with confirmatory genetic testing.

Results We encountered 81 cases with a positive cfDNA test (T21: 49.4%; T18: 9.9%; T13: 8.6%; SCA: 22.2%; 22q12del: 8.6%). The PPV was 95.0% for T21, but considerably lower for T18 (55.6%) and T13 (28.6%). For SCAs it was 23.1% and no case with DiGeorge syndrome was confirmed. 63% of the patients had not received a fetal anomaly scan before cfDNA testing. In first-trimester fetuses with a cfDNA test predicting an autosomal aneuploidy, fetal anomalies were detected in 90.3% of the cases. No false positive case had an abnormal US result.

Conclusions Despite the excellent specificity of cfDNA tests, the PPV for aneuploidies other than T21 is low in routine practice. In discordance with the current guidelines, cfDNA test is often used without a previous detailed anomaly scan. Our data provide valuable information to assist patient counselling and shared decision making.

Amniocentesis learning curve using a low-cost simulation model to teach maternal-fetal medicine fellows

OBJECTIVE

To describe the learning curve for amniocentesis among Maternal-Fetal Medicine (MFM) fellows using a low-cost simulation model in Mexico.

METHODS

Fourteen first- and second-year MFM fellows with no previous experience in amniocentesis participated in this single-center prospective study from March to June of 2019. The study was approved by the Institutional Review Board at the Instituto Nacional de Perinatologia and written informed consent was obtained from all participants. After an introductory course based on a standardized technique for amniocentesis, each fellow performed this procedure using a low-cost simulation model; experienced operators supervised the procedures. Learning curves were then created using cumulative sum analysis. Thresholds for acceptable and unacceptable failure rates were defined as 10% and 25%, respectively.

RESULTS

Experienced MFM specialists evaluated 3675 procedures. On average, MFM fellows performed 263 ± 53 procedures. The mean number to achieve competence was 255 ± 53. The overall failure rate among the trainees was 16%.

CONCLUSION

We describe individual learning curves for amniocentesis among MFM fellows using a low-cost simulation model. This approach allows direct assessment of proficiency in amniocentesis before clinical practice.

Risk of fetal loss following amniocentesis or chorionic villus sampling in twin pregnancy: systematic review and meta-analysis

OBJECTIVE

To assess the rate of fetal loss following amniocentesis or chorionic villus sampling (CVS) in twin pregnancy.

METHODS

MEDLINE, EMBASE and Cochrane databases were searched for studies reporting procedure-related complications following amniocentesis or CVS in twin pregnancy. The primary outcome was the rate of procedure-related fetal loss. The secondary outcomes were fetal loss occurring before 24 weeks of gestation and fetal loss occurring within 4 weeks after the procedure. Head-to-head meta-analyses were used to compare directly each outcome, between women undergoing amniocentesis and those not undergoing amniocentesis and between women undergoing CVS and those not undergoing CVS, and to compute pooled risk differences (RD) between women exposed and those not exposed to each invasive procedure. Additionally, meta-analyses of proportions were used to estimate the pooled rates of each of the three outcomes in women undergoing amniocentesis or CVS and in controls.

RESULTS

Sixteen studies (3419 twin pregnancies undergoing and 2517 not undergoing an invasive procedure) were included. Head-to-head meta-analyses comparing directly twin pregnancies undergoing and those not undergoing amniocentesis showed a higher risk for overall fetal loss in those undergoing amniocentesis (odds ratio (OR), 1.46 (P = 0.04); RD, 0.013 (P = 0.04)), while there was no difference in the risk of either fetal loss before 24 weeks of gestation (OR, 1.59 (P = 0.06); RD, 0.010 (P = 0.11)) or fetal loss within 4 weeks after the procedure (OR, 1.38 (P = 0.3); RD, 0.003 (P = 0.8)). Overall, the pooled rate of fetal loss was 2.4% (95% CI, 1.4-3.6%) in twin pregnancies undergoing amniocentesis compared with 2.4% (95% CI, 0.9-4.6%) in those not undergoing amniocentesis. Head-to-head meta-analyses directly comparing twin pregnancies undergoing and those not undergoing CVS showed no significant difference in either overall fetal loss (OR, 1.61 (P = 0.5); RD, 0.003 (P = 0.8)) or fetal loss before 24 weeks of gestation (OR, 1.61 (P = 0.5); RD, 0.003 (P = 0.8)). Overall, the pooled rate of fetal loss was 2.0% (95% CI, 0.0-6.5%) in twin pregnancies undergoing CVS compared with 1.8% (95% CI, 0.3-4.2%) in those not undergoing CVS.

CONCLUSION

The risk of fetal loss following amniocentesis and CVS in twins is lower than reported previously and the rate of fetal loss before 24 weeks of gestation, or within 4 weeks after the procedure, did not differ from the background risk in twin pregnancy not undergoing invasive prenatal testing. These data can guide prenatal counseling for twin pregnancies undergoing invasive procedures. © 2020 International Society of Ultrasound in Obstetrics and Gynecology.

Ante-natal counseling in phacomatoses

OBJECTIVES

Phacomatoses are a group of neuro-oculo-cutaneous syndromes/ neurocutaneous disorders, involving structures arising from the embryonic ectoderm. Most of phacomatoses including the most common ones:, neurofibromatosis type I and type II (NF1, NF2) and tuberosclerosis complex (TSC), are autosomal dominant genetic disorders with full penetrance and variable expression. As no effective treatment exists, the only way to prevent the disease, is by prenatal genetic diagnosis (either chorionic villus sampling-CVS or amniocentesis-AC) and termination of pregnancy or performing preimplantation genetic testing (PGT). As the risk for an affected offspring is 50% in every pregnancy of an affected parent, prenatal, and preimplantation testing are of great importance. However, those procedures are associated with technical and ethical concerns. This chapter shortly reviews the common phacomatoses emphasizes their genetics and inheritance. We will review the common methods for prenatal and preimplantation diagnoses and discuss its use in common phacomatoses.

CONCLUSION

Phacomatoses are common autosomal dominant genetic conditions with variable expression. Ante-natal genetic diagnosis is an appropriate approach for family planning in individuals affected by phacomatosis or parents of an affected child.

Evaluation of chromosomal abnormalities and copy number variations in late trimester pregnancy using cordocentesis

Because the numbers of detected fetal abnormalities increase as gestation progresses, we evaluated the safety and efficacy of cordocentesis for single nucleotide polymorphism (SNP) analysis tests in 754 women during third trimester pregnancy. Conventional karyotyping was performed on all fetuses, and Affymetrix CytoScan HD was used for SNP-array testing. In addition to the 24 cases with chromosomal abnormalities detected with conventional karyotyping analysis, the SNP-array test identified 56 (7.4%) cases with normal karyotypes but abnormal copy number variations (CNVs). Of those, 24 were pathogenic CNVs and 32 were of uncertain clinical significance. In 742 of the cases, there were abnormal sonographic findings, and cytogenetic abnormalities were detected in 76 cases (10.2%). The largest number of abnormalities involved multiple malformations (21.7%), followed by defects in the lymphatics or effusion (19.0%) or urogenital system (15.3%). The use of SNP-array test fully complemented chromosome karyotype analysis after late cordocentesis. It also improved the detection rate for fetal chromosomal abnormalities and was effective for preventing and controlling the occurrence of birth defects.

The effect of maternal body mass index and gestational age on circulating trophoblast yield in cell-based noninvasive prenatal testing

OBJECTIVE

To examine the effects of maternal body mass index (BMI) and gestational age (GA) on the number of single circulating trophoblasts (SCT).

METHODS

Maternal blood was collected in 20 to 40 mL. All singleton pregnant women at any gestation were recruited. Trophoblasts were recovered by immunomagnetic enrichment and stained for cytokeratin and CD45. Candidate trophoblasts were identified by fluorescence microscopy.

RESULTS

Blood samples were collected from 425 singleton pregnancies from April 2018 to December 2019. At least one candidate cell was identified in 88% (373/425). There was an inverse correlation between trophoblasts yield and increasing BMI (r = -0.19, P < .001). The mean ± SD number of trophoblasts/mL was 0.12  ± 0.22 in the underweight group (n = 5), 0.23 ± 0.25 in the normal weight (n = 169), 0.18 ± 0.19 in the overweight (n = 114), and 0.13 ± 0.15 in the obese (n = 109). Significantly more cells were identified in the normal weight than those in the obese (P = .001). In addition, the mean ± SD number of cells/mL was 0.21  ± 0.21 at GA of 10 to 14 weeks (n = 260), 0.14 ± 0.23 at GA ≥15 (n = 102) and 0.12 ± 0.12 at GA <10 (n = 63); P < .001.

CONCLUSION

The lower number of SCT was identified from the samples of women with a high BMI. Cell recovery for SCT testing seems optimal at GA of 10 to 14 weeks, but earlier and later testing is still possible.

Diagnostic Testing for Patients with Spinal Muscular Atrophy

Diagnostic genetic testing for spinal muscular atrophy is key in establishing early diagnosis for affected individuals. Prenatal carrier testing of parents with subsequent testing of the fetus for homozygous SMN1 gene deletion in those at risk of this autosomal recessive disorder as well as newborn screening can identify the vast majority of affected individuals before the onset of symptoms. Patients presenting symptomatically must be genetically confirmed as soon as possible because targeted treatments are now available that profoundly impact symptoms and improve quality of life.

Influence of the detection of parent-of-origin on the pregnancy outcomes of fetuses with copy number variation of unknown significance

The widespread application of high-resolution chromosome detection technology in clinical practice has identified many variants of unknown significance (VOUS) in prenatal diagnosis. The purpose of this study was to prospectively analyze the chromosomal results of parents and the follow-up information of pregnancy outcomes of prenatal samples with VOUS, so as to determine the influence of the detection of parent-of-origin on the pregnancy outcomes of fetuses with VOUS. The present study analyzed amniotic fluid samples obtained from women with different risk indications between February 2017 and December 2018. The samples were subjected to copy number variation sequencing, and detection of parent-of-origin was suggested in cases of samples with VOUS. The pregnancy outcome was followed up. In a total of 14073 amniotic fluid samples, 729 cases of VOUS were detected (5.2%, 729/14073) and 721 cases were followed up successfully. Among the 721 cases, 525 patients agreed to detect the parent-of-origin (72.8%, 525/721). It was revealed that the VOUS in 460 of the fetuses were hereditary (87.6%, 460/525). The percentages of abnormal pregnancy outcomes (included pregnancy loss, fetal pathological abnormality, preterm delivery, neonatal death, birth defects) in the inherited, de novo, and refusal to detect the parent-of-origin (i.e. unknown origin) groups were 4.3% (20/460), 6.2% (4/65), and 6.6% (13/196), respectively. There was no significant difference among the three groups (P > 0.05). The rate of voluntary termination of pregnancy (TOP) in the unknown origin group was significantly higher than that in the group that had determined the parent-of-origin (14.3% vs 7.4%, P = 0.005). There is currently no evidence that suggests that the proportion of abnormal pregnancy outcomes is higher in fetuses with VOUS than in other fetuses. However, the present study revealed that determining the parent-of-origin affects the decision to undergo voluntary TOP, as the rate of voluntary TOP in the group that refused detection was higher than that in the group that consented.

The decline of amniocentesis and the increase of chorionic villus sampling in modern perinatal medicine

Objective The aims of this study were to determine the rate of change by type of diagnosis by transabdominal chorionic villus sampling (TA-CVS) vs. amniocentesis for aneuploidy and to describe a successful and intensive international training program for TA-CVS in ongoing pregnancies. Methods We conducted a retrospective cohort study of all deliveries from 2010 to 2018 in Sardinia. All invasive diagnostic procedures are conducted at a single regional perinatal referral center. Descriptive statistics were used to compare data across groups, and inter-correlations between variables were investigated by Pearson's correlation coefficient. We subsequently describe the international trainee experiences in TA-CVS over a 35-year period. Results A total of 101,025 deliveries occurred over 9 years. The number of deliveries (13,413-9143, P < 0.0001) and total invasive diagnostic procedures (1506-858 per year, P = 0.019) declined over this period. The percentage of deliveries undergoing invasive diagnostic procedures remained steady (mean: 12.2%). In 2010, TA-CVS made up 32.3% of all invasive diagnostic procedures, while amniocentesis made up 67.7%. By 2018, TA-CVS made up 61.3% of the invasive diagnostic procedures, and amniocentesis, only 38.7%. The rate of TA-CVS increased over 9 years, while the rate of amniocentesis declined. A total of 236 trainees from 39 different countries and 5 different continents rotated through this site. The average length of stay was 2.4 weeks. Conclusion We demonstrate an increasing prevalence of TA-CVS vs. amniocentesis in the current era of prenatal testing and underscore the importance of continuing to train specialists skilled in TA-CVS. Our global operative experience is feasible and sustainable and will have a lasting impact on physicians conducting invasive fetal procedures.

DiGeorge syndrome chromosome region deletion and duplication: Prenatal genotype-phenotype variability in fetal ultrasound and MRI

OBJECTIVE

The aim of the study was to assess genotype-phenotype correlation of prenatally diagnosed fetal DGS and dup22q11 syndrome by fetal molecular genetic analysis, fetal ultrasound, and/or MRI.

METHODS

In this retrospective consecutive case series, pregnant women were screened for fetal anomalies during a period of 10 years. Fetal genotype was assessed in 72 cases upon the occurrence of five prenatal fetal phenotypic features: cardiac anomalies, hypo/aplastic thymus, craniofacial malformations, urinary abnormalities, or IUGR; genotype-phenotype correlation was tested to potentially improve prenatal diagnosis of fetal DGS and dup22q11 syndrome.

RESULTS

Fetal genotypes of deletions or duplications in proximal clusters of LCR22s (A-B) were associated with fetal cardiac anomalies in combination with hypo/aplastic thymus and craniofacial malformations, suggesting a correlation with deleted HIRA. TOF associated with aplastic thymus in combination with renal defects indicated a relevant correlation with TBX1 deletion. Deletions in central LCR22s (B-D) with the loss of CRKL supposed a trend of genotype-phenotype correlation with fetal urinary abnormalities.

CONCLUSION

Genotype-phenotype correlation might improve prenatal diagnosis of fetal DGS and dup22q11 syndrome. Hence, prenatal screening and counseling is highly enhanced by a combination of fetal molecular genetic analysis, fetal ultrasound, and/or MRI. The implications of these findings remain to be explored.

Risk of miscarriage following amniocentesis or chorionic villus sampling: systematic review of literature and updated meta-analysis

OBJECTIVE

To estimate the procedure-related risk of miscarriage after amniocentesis and chorionic villus sampling (CVS) based on a systematic review of the literature and an updated meta-analysis.

METHODS

A search of MEDLINE, EMBASE and The Cochrane Library was carried out to identify studies reporting complications following CVS or amniocentesis. Eligible for inclusion were large controlled studies reporting data for pregnancy loss prior to 24 weeks' gestation. Study authors were contacted when required to identify additional necessary data. Data for cases that had an invasive procedure and controls were inputted into contingency tables and the risk of miscarriage was estimated for each study. Summary statistics based on a random-effects model were calculated after taking into account the weighting for each study included in the systematic review. Procedure-related risk of miscarriage was estimated as a weighted risk difference from the summary statistics for cases and controls. Subgroup analyses were performed according to the similarity in risk levels for chromosomal abnormality between the invasive-testing and control groups. Heterogeneity was assessed using the I² statistic. Egger's bias was estimated to assess reporting bias in published studies.

RESULTS

The electronic search yielded 2943 potential citations, from which 12 controlled studies for amniocentesis and seven for CVS were selected for inclusion in the systematic review. A total of 580 miscarriages occurred following 63 723 amniocentesis procedures, resulting in a weighted risk of pregnancy loss of 0.91% (95% CI, 0.73-1.09%). In the control group, there were 1726 miscarriages in 330 469 pregnancies with a loss rate of 0.58% (95% CI, 0.47-0.70%). The weighted procedure-related risk of miscarriage following amniocentesis was 0.30% (95% CI, 0.11-0.49%; I²  = 70.1%). A total of 163 miscarriages occurred following 13 011 CVS procedures, resulting in a risk of pregnancy loss of 1.39% (95% CI, 0.76-2.02%). In the control group, there were 1946 miscarriages in 232 680 pregnancies with a loss rate of 1.23% (95% CI, 0.86-1.59%). The weighted procedure-related risk of miscarriage following CVS was 0.20% (95% CI, -0.13 to 0.52%; I²  = 52.7%). However, when studies including only women with similar risk profiles for chromosomal abnormality in the intervention and control groups were considered, the procedure-related risk for amniocentesis was 0.12% (95% CI, -0.05 to 0.30%; I²  = 44.1%) and for CVS it was -0.11% (95% CI, -0.29 to 0.08%; I²  = 0%).

CONCLUSIONS

The procedure-related risks of miscarriage following amniocentesis and CVS are lower than currently quoted to women. The risk appears to be negligible when these interventions were compared to control groups of the same risk profile. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

5-Year review on amniocentesis and its maternal fetal complications

Background Amniocentesis is a well-known invasive procedure which is commonly carried out in the second trimester. The indication for amniocentesis varies throughout countries and centers. Despite providing significant prenatal diagnosis; many maternal and fetal complications have been reported from previous studies. Materials and methods This retrospective study aimed to determine the maternal and fetal complications following amniocentesis. This study involved all patients who underwent amniocentesis from January 2012 until June 2017 in a tertiary centre. Maternal age, parity, premorbid medical conditions, amniocentesis indications, gestational age during amniocentesis, karyotyping results, complications during and post procedure and the fetal outcomes were reviewed and analyzed. Results One hundred and fourteen patients' medical records were reviewed and the majority of patients (50.9%) ranged in age from age 30 to 39 years old with mean age of 34.29 years. Amniocentesis was performed during the second trimester in the majority of patients (71.1%). The indications for amniocentesis in this study were polyhydramnios (7.9%), advanced maternal age (9.6%), risk of Down's syndrome (31.6%), increased risk of Patau syndrome (6.1%), increased risk of Edward's syndrome (4.4%) and abnormal fetal ultrasonography (70.2%). Cytogenetics results of amniocentesis were normal in 82 patients (71.9%). The majority of patients (86.0%) had no complications. Two patients (12.5%) had intrauterine death presumed to be procedural related. Conclusion This 5-year retrospective study on amniocentesis procedure showed that the majority of amniocentesis were safe as 86.0% of the patients were free from any complications. Anticipating its complication is important as there is always a risk even though it is a safe procedure in general.

Transcervical chorionic villus sampling in a low-cost simulation model: Learning curve of maternal-fetal medicine fellows in Mexico

The implementation of a low‐cost simulation model and cumulative sum analysis enables training and monitoring of individual learning curves for transcervical chorionic villus sampling.

The contingent use of cell-free fetal DNA for prenatal screening of trisomies 21, 18, 13 in pregnant women within a national health service: A budget impact analysis

OBJECTIVE

Non-invasive prenatal testing (NIPT) based on cell-free fetal DNA (cffDNA) is highly accurate in the detection of common fetal autosomal trisomies. Aim of this project was to investigate short-term costs and clinical outcomes of the contingent use of cffDNA for prenatal screening of trisomies 21, 18, 13 within a national health service (NHS).

METHODS

An economic analysis was developed from the perspective of the Italian NHS to compare two possible scenarios for managing pregnant women: women managed according to the Standard of Care screening (SoC) vs a cffDNA scenario, where Harmony Prenatal Test was introduced as a second line screening choice for women with an "at risk" result from SoC screening.

RESULTS

The introduction of cffDNA as a second line screening test, conditional to a risk ≥ 1:1,000 from SoC screening, showed a 3% increase in the detection of trisomies, with a 71% decrease in the number of invasive tests performed. Total short-term costs (pregnancy management until childbirth) decreased by € 19 million (from € 84.5 to 65.5 million).

CONCLUSION

The adoption of the Harmony Prenatal Test in women resulting at risk from SoC screening, implied a greater number of trisomies detection, together with a reduction of the healthcare costs.

X-chromosome inactivation pattern of amniocytes predicts the risk of dystrophinopathy in fetal carriers of DMD mutations

OBJECTIVE

To predict the risk of dystrophinopathy in fetal carriers of dystrophin gene (DMD) mutations.

METHODS

Twenty-three pregnant women, with a total of 25 female fetuses carrying DMD mutations, were recruited. Among them, 13 pregnant women who participated in this study were only used to analyse the incidence of induced abortion after fetuses were diagnosed as dystrophinopathy carriers. Eleven fetal carriers from 10 pregnant women were tested to analyse X-chromosome inactivation (XCI) using amniocytes to assess the risk of dystrophinopathy. Follow-ups were conducted on all cases.

RESULTS

Approximately one-third of fetuses were aborted before assessing the risk of dystrophinopathy. XCI analysis of amniocytes showed that 10 fetuses had random XCI patterns, and one fetus exhibited a highly skewed XCI pattern (100:0) with primary expression of the maternal X chromosome that carried the mutant allele. These 11 fetal carriers were born, and follow-up showed that the girl who showed the skewed XCI pattern as a fetus was diagnosed with Duchenne muscular dystrophy (DMD) at the age of four. The others did not present with dystrophinopathy-associated symptoms.

CONCLUSIONS

XCI was significantly implicated in symptomatic female carriers of dystrophinopathies, and XCI pattern analysis of amniocytes may be useful in predicting the risk of dystrophinopathy in fetal carriers.

Mother-to-child transmission of hepatitis B virus after amniocentesis: A retrospective matched cohort study

OBJECTIVE

The objective of this study is to determine whether amniocentesis increases the risk of mother-to-child transmission (MTCT) of hepatitis B virus (HBV) and evaluate risk factors for MTCT.

METHODS

One hundred forty-three hepatitis B surface antigen (HBsAg)-positive women with amniocentesis were enrolled into the amniocentesis group. Six hundred five nonamniocentesis cases were matched with amniocentesis cases based on maternal viral loads, antiviral therapy regimens, and delivery dates. MTCT of HBV was defined as HBsAg and/or DNA positivity in infants from birth to age 7 to 12 months.

RESULTS

Mother-to-child transmission rate was significantly higher in HBsAg-positive women with amniocentesis than in those without amniocentesis (2.80% vs 0.50%; relative risk [RR], 5.64; 95% CI, 1.28-24.93). In the amniocentesis group, maternal HBV DNA more than or equal to 7.0 log₁₀ IU/mL and hepatitis B e-antigen (HBeAg) positivity were associated with higher MTCT rates than maternal HBV DNA less than 7.0 log₁₀ IU/mL (10.81% vs 0%, p = .004) and HBeAg negativity (8.16% vs 0%, p = .013), and antiviral therapy reduced MTCT rate from 14.3% to 0% (p = .554) when maternal HBV DNA was more than or equal to 7.0 log₁₀ IU/mL.

CONCLUSIONS

Amniocentesis increases the risk of MTCT in women with hepatitis B, and maternal HBV DNA more than or equal to 7.0 log₁₀ IU/mL and HBeAg positivity are risk factors for MTCT. Antiviral therapy may be effective to prevent MTCT after amniocentesis in highly viremic mothers.

Molecular cytogenetic identification of small supernumerary marker chromosomes using chromosome microarray analysis

Background

This study aimed to evaluate the feasibility of chromosomal microarray analysis (CMA) in detecting the origin and structure of small supernumerary marker chromosomes (sSMCs) in prenatal and postnatal cases and to clarify sSMC-related genotype-phenotype correlations.

Results

Thirty-three cases carrying sSMCs were identified by banding cytogenetics. Of these cases, twenty-nine were first characterized by CMA and only two by FISH. The remaining two cases were excluded for their refusal to accept further examination. The chromosomal origins of twenty-two cases were successfully identified, in which pathogenetic copy number variations (PCNVs) were found in sixteen cases, four cases showed variants of uncertain significance (VOUS), one case showed benign CNVs, and one case showed probable PCNVs. For the nine cases with negative CMA results, only one of them contained centromere heterochromatin likely due to its normal phenotype, whereas reasons for the remaining eight cases were uncertain. We also found that CMA results indicating pathogenic abnormalities further affect the rate of pregnancy termination.

Conclusions

This study showed that CMA combined with cytogenetic analysis is particularly effective in identifying sSMCs. However, in order to establish sSMC-related genotype-phenotype correlations, the inclusion of more sSMC cases will be necessary in future studies.

The diagnostic value of a detailed first trimester anomaly scan in fetuses with increased nuchal translucency thickness

Objectives To assess the diagnostic value of an early anomaly scan in fetuses with increased nuchal translucency (NT) in the prediction of aneuploidy. Methods In this study we analyzed the data of pregnant women obtained at their first trimester screening in our unit. The detailed examination routinely includes measurement of NT and a scan for anatomical defects. For fetuses with an NT≥3.5 mm, the diagnostic power of early major sonographic findings (MSF) regarding abnormal karyotype was calculated. Results A total of 7352 first trimester examinations were screened. Two hundred and twenty-two fetuses with an NT≥3.5 mm were analyzed. The median gestational age was 12.5 weeks (range 11.0-14.6) and the median NT was 5.1 mm (range 3.5-15.3). MSF were detected in 51.8% of fetuses with increased NT. Among 115 fetuses with MSF, 91 were aneuploid, yielding a positive predictive value for aneuploidy of 79.1%. In the absence of MSF, the negative predictive value was 70.1%. The presence of MSF was significantly predictive for aneuploidy both in bivariate and multivariate regression analysis. Conclusion Our study underlines the importance of a detailed anatomical ultrasound in fetuses with increased NT, as MSF occurred frequently. However, the diagnostic value of MSF regarding aneuploidies appears to be moderate.

A survey of current clinical practice of chorionic villus sampling

OBJECTIVE

The number of invasive procedures (chorionic villus sampling (CVS) or amniocentesis) for fetal testing is decreasing because of the availability of non-invasive prenatal test (NIPT) leading to a centralisation of prenatal diagnostic services to accredited fetal medicine centres. A new survey was conducted 10 years after the previous one to update the current clinical practice among clinicians who regularly perform CVS.

METHOD

Consultants from 32 centres in the United Kingdom were invited to take part in an online survey evaluating: The total number of CVS procedures carried out in the unit in a typical week, the preferred route (transabdominal [TA] vs transcervical [TC]), technique (use of local anaesthetic [LA] and needle technique).

RESULTS

Response rate was 96.9%; TA was the preferred route (96.8%) in all centres except one. Single-needle technique is used exclusively in half the centres (51.6%). LA is used by most operators (90.3%) before the procedure. Three centres did not routinely use LA for CVS.

CONCLUSIONS

Operators across the United Kingdom almost exclusively use the TA route for CVS with single-needle technique in 51.6% of cases. The use of LA prior to CVS is a very common practice in the United Kingdom.

Application of chromosomal microarray to investigate genetic causes of isolated fetal growth restriction

Background

Application of chromosomal microarray analysis (CMA) to investigate the genetic characteristics of fetal growth restriction (FGR) without ultrasonic structural anomalies at 18–32 weeks.

Methods

This study includes singleton fetuses with the estimated fetal weight (EFW) using the formula of Hadlock C below the 10th percentile for gestational age. FGRs without structural anomalies were selected, and the ones at high risk of noninvasive prenatal testing for trisomy 13, 18 and 21 would be excluded. The cases were divided into two groups: early-onset group (< 24^+ 0 weeks) and late-onset group (24–33 weeks). All patients were offered invasive prenatal testing with CMA and karyotype analysis.

Results

CMA detected 10 pathogenic copy number variants and 2 variant of uncertain significance case. CMA has a 5.5% (7/127) incremental yield of pathogenic chromosomal abnormalities over karyotyping. The positive detected rate was 9.6% (5/52) in early-onset group and 9.3% (7/75) in late-onset group respectively.

Conclusions

When FGR without structural anomaly is diagnosed before 33 weeks, an invasive prenatal procedure is strongly recommended. CMA can identify a 5.5% (7/127) incremental detection rate of pathogenic chromosomal abnormalities, which would impact clinical management for FGR.

Total pregnancy loss after chorionic villus sampling and amniocentesis: a cohort study

OBJECTIVES

To identify maternal-, operator- and procedure-related variables that affect procedure-related pregnancy loss after transcervical (TC) and transabdominal (TA) chorionic villus sampling (CVS) and amniocentesis and to estimate the rates of spontaneous and procedure-related loss in comparable subgroups of women.

METHODS

This was a retrospective cohort study conducted at the University Medical Center Groningen and the Academic Medical Center, The Netherlands. Databases of both centers were searched to identify singleton pregnancies that had undergone a combined test and/or anomaly scan at around 20 weeks' gestation, or an invasive procedure (CVS and/or amniocentesis) between January 2001 and December 2011. Maternal characteristics, obstetric history, technical aspects of the invasive procedure, ultrasound examinations and fetal and neonatal outcomes were available for 29 201 cases. Women were categorized, according to the type of examination they had received, into the following five groups: first-trimester combined test (and 20-week anomaly scan); 20-week anomaly scan only; CVS; amniocentesis; amniocentesis after unsuccessful CVS. Rates of fetal loss were compared between groups.

RESULTS

Variables significantly associated with a higher rate of fetal loss were, for CVS, repeat attempts during the procedure, use of TC cannula instead of biopsy forceps, gestational age at procedure ≥ 13 weeks and a pregnancy after assisted reproductive techniques, and, for amniocentesis, if indication was fetal anomaly or family history of anomalies and repeat attempts during the procedure. In women aged ≥ 36 years who did not undergo an invasive procedure, spontaneous fetal loss rate (FLR) after first-trimester combined test was 1.40%, whereas after CVS, FLR was 2.76% and 2.43% for a TC and TA approach, respectively. The additional risk of fetal loss with TC-CVS was therefore 1.36% (1 : 74), which varied according to the instrument used (0.27% for forceps and 3.12% for cannula), and with TA-CVS was 1.03% (1 : 97). In women aged ≥ 36 years who underwent a 20-week anomaly scan only, spontaneous FLR was 0.63%. In women who underwent amniocentesis solely because of advanced maternal age, FLR was 1.11%. The additional risk of fetal loss with amniocentesis was 0.48% (1 : 208).

CONCLUSION

The total rate of procedure-related fetal loss after TA- and TC-CVS and amniocentesis appears lower than the risks on which women are currently counseled. There was a trend for a decrease in risk when the level of experience of the operator increased. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

Declining invasive prenatal diagnostic procedures: A comparison of tertiary hospital and national data from 2012 to 2015

BACKGROUND

In recent years, the superior accuracy of maternal plasma cell-free DNA-based prenatal screening has resulted in >50% national decline in amniocenteses and chorionic villus sampling (CVS), creating new implications for specialist training.

OBJECTIVE

To compare the annual figures on amniocenteses and CVS in a tertiary hospital with national population-based trends between 2012 and 2015.

METHODS

Retrospective study examining the amniocentesis and CVS procedures performed in a tertiary hospital between 2012 and 2015. Numbers of procedures, indications for testing, type of test and diagnostic results were analysed. Trends in the annual numbers of procedures were compared to national population-based data from Medicare Benefits Schedule database.

RESULTS

The annual numbers of diagnostic procedures in our tertiary centre fell from 267 to 215 over the study period, representing a 19.5% decline. This was significantly smaller than the corresponding national decline of 53.7% for the same period (P < 0.0001). In 2015, ultrasound abnormality (including nuchal translucency ≥ 3.5 mm) surpassed high-risk screening results as the most common indication for invasive testing. Thirty percent of procedures performed for an ultrasound abnormality occurred prior to 18 weeks gestation.

CONCLUSION

Our tertiary centre experienced a relatively smaller decline in prenatal diagnostic procedures compared with national figures, largely due to an increase in testing for ultrasound abnormalities. Our results demonstrate the increasing contribution of first trimester ultrasound in the detection of fetal abnormalities in the cell-free DNA era and the continued viability of specialist training in invasive procedures.