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Steel syndrome (STLS) encompasses characteristic facies, dwarfness, irreducible bilateral hip and radial head dislocation, and carpal bone coalition due to COL27A1 mutations. Two consecutive pregnancies in a non-consanguineous couple were terminated because of severe fetal anomalies. Complete autopsies with microscopic exam were performed on both fetuses. Next-generation-based clinical exome sequencing was applied to the first fetus. Exome sequencing results, parental segregation, and affection of the second fetus were confirmed by Sanger sequencing. Both fetuses had signs consistent with STLS. Bilateral capitulum humeri absence explained radial head dislocation in STLS. Metaphyseal cartilage showed severe disorganization. Resting cartilage was hypercellular, organized in irregular nests limited by acellular matrix. Two variants in COL27A1 (c.2548G>A -p.Gly850Arg- and c.3249+1G> T) were found in both fetuses in compound heterozygosity with parental Mendelian segregation. This is the first report to include histology of STLS. The COL27A1 variants here described increase the number of mutations associated with STLS.

Objective: The aim of the study was to assess the diagnostic yield of 2 different next-generation sequencing (NGS) approaches: gene panel and “solo” clinical exome sequencing (solo-CES), in fetuses with structural anomalies and normal chromosomal microarray analysis (CMA), in the absence of a known familial mutation. Methodology: Gene panels encompassing from 2 to 140 genes, were applied mainly in persistent nuchal fold/fetal hydrops and in large hyperechogenic kidneys. Solo-CES, which entails sequencing the fetus alone and only interpreting the Online Mendelian Inheritance in Man genes, was performed in multisystem or recurrent structural anomalies. Results: During the study period (2015–2020), 153 NGS studies were performed in 148 structurally abnormal fetuses with a normal CMA. The overall diagnostic yield accounted for 35% (53/153) of samples and 36% (53/148) of the fetuses. Diagnostic yield with the gene panels was 31% (15/49), similar to 37% (38/104) in solo-CES. Conclusions: A monogenic disease was established as the underlying cause in 35% of selected fetal structural anomalies by gene panels and solo-CES.

STUDY QUESTION Can maternal plasma cell-free DNA (cfDNA) detect chromosomal anomalies in early pregnancy loss (EPL) and recurrent pregnancy loss (RPL)? SUMMARY ANSWER Genome-wide cfDNA testing can serve as an alternative to cytogenetic analysis in products of conception (POCs) in RPLs and can guide further management. WHAT IS KNOWN ALREADY Random chromosomal anomalies are the single most common cause for EPL and RPL. Cytogenetic analysis in POCs may be used to direct management in RPL because the detection of random chromosomal anomalies can eliminate further unwarranted testing. STUDY DESIGN, SIZE, DURATION This was a prospective diagnostic test study from March 2018 to January 2019 of 109 patients experiencing pregnancy loss before 14 weeks gestation at a tertiary-care academic medical center. PARTICIPANTS/MATERIALS, SETTING, METHODS Blood samples were drawn for genome-wide cfDNA testing prior to chorionic villous sampling for cytogenetic analysis of POCs with both short-term cultures (STCs) and long-term cultures (LTCs). Final analysis included 86 patients with non-mosaic cytogenetic results in POCs and available cfDNA results. Aneuploidy detection rates by cfDNA testing and POC cytogenetic analysis were compared. The first 50 samples served as the Training Set to establish pregnancy loss-specific log-likelihood ratio (LLR) thresholds using receiver-operator characteristic (ROC)-like analyses. These were then used for the entire cohort. MAIN RESULTS AND THE ROLE OF CHANCE Seventy-eight samples (71.5%) had results available from both STC and LTC; 12 samples (11%) had a result from STC only, and 7 samples (6.4%) had a result from LTC only. A chromosomal anomaly was detected in 55/86 (64%). The rates of chromosomal anomalies were 61, 72, 73 and 44% in patients undergoing their first, second, third and ≥4th pregnancy losses, respectively. The median cfDNA fetal fraction was 5%. With standard LLR thresholds used for noninvasive prenatal screening, the sensitivity of cfDNA in detecting aneuploidy was 55% (30/55) and with a specificity of 100% (31/31). Using pregnancy loss-specific LLR thresholds, the sensitivity of cfDNA in detecting aneuploidy was 82% (45/55), with a specificity of 90% (28/31). The positive and negative likelihood ratios were 8.46 and 0.20, respectively. Fetal sex was correctly assigned in all cases. LIMITATIONS, REASONS FOR CAUTION Cases with a false-positive result by cfDNA analysis would not receive the indicated RPL workup. Specificity could be improved by using a fetal fraction (FF) cutoff of 4%, but this would result in exclusion of more than a quarter of cases. WIDER IMPLICATIONS OF THE FINDINGS cfDNA-based testing can serve as an alternative to POC cytogenetic analysis and can guide further RPL management: if cfDNA demonstrates aneuploidy, no further action is taken and if no abnormality is detected, the recommended RPL workup is performed. STUDY FUNDING/COMPETING INTEREST(S) Cell-free DNA testing was funded by Illumina, Inc., San Diego, CA. Y.Y. is a member of Illumina’s Clinical Expert Panel and has received travel grants. A.B. has received travel grants from Illumina. All authors have no competing interest to declare.

OBJECTIVE To assess the frequency of atypical chromosomal and submicroscopic anomalies, as well as fetal structural abnormalities, observed on first-trimester ultrasound scan in fetuses with nuchal translucency (NT) thickness > 99th centile, in order to evaluate the suitability of using standard cell-free DNA (cfDNA) testing as the sole screening test in these pregnancies. METHODS This was a retrospective cohort study of 226 fetuses with NT > 99th centile at 11-14 weeks' gestation, between January 2013 and December 2017, in a clinical setting in which greater than 95% of pregnant women receive first-trimester combined screening. All patients underwent genetic testing by means of quantitative fluorescence polymerase chain reaction and chromosomal microarray analysis, mainly in chorionic villus samples. We assessed the theoretical yield of two cfDNA testing models, targeted cfDNA (chromosomes 21, 18 and 13) and extended cfDNA (chromosomes 21, 18, 13 and sex chromosomes), and compared it with that of cytogenetic testing and ultrasound assessment in the first and second or third trimesters. RESULTS In the 226 fetuses analyzed, cytogenetic testing revealed 84 (37%) anomalies, including 68 typical aneuploidies (involving chromosomes 13, 18 or 21), six sex chromosome aneuploidies (four cases of monosomy X and two of trisomy X), three clinically relevant atypical chromosomal anomalies (one trisomy 22, one trisomy 21 mosaicism and one unbalanced translocation), five submicroscopic pathogenic variants and two cases with Noonan syndrome. Targeted and extended cfDNA testing would miss at least 12% (10/84) and 19% (16/84), respectively, of genetic anomalies, accounting for 4.4% and 7.1% of the fetuses with an increased NT, respectively. Finally, of the 142 fetuses with no identified genetic anomaly, a major fetal malformation was observed in 15 (10.6%) fetuses at the early anomaly scan, and in 19 (13.4%) in the second or third trimester. CONCLUSIONS cfDNA does not appear to be the appropriate genetic test in fetuses with NT > 99th centile, given that it would miss 12-19% of genetic anomalies in this group. Additionally, first-trimester ultrasound will identify a major structural abnormality in 11% of the fetuses with NT > 99th centile and no genetic anomaly. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Objective: To assess whether the cisterna magna (CM) width measured in first-trimester fetuses is a useful marker for aneuploidy detection. Methods: This was a prospective study in 2 different cohorts in a tertiary referral center. The first cohort comprised 913 fetuses from the general pregnancy population during the period 2012–2016 and was used to construct the CM reference ranges applying the λ-μ-σ (LMS) method. The second cohort included 714 high-risk fetuses undergoing chorionic villus sampling during the period 2012–2016. Mean detection rates using the 95th percentile for CM width observed in chromosomal anomaly groups were compared with those obtained in chromosomally normal fetuses. Results: The 50th percentile for CM ranged from 1.66 to 2.75 mm when crown-rump length (CRL) increased from 45 to 84 mm. Among high-risk fetuses, the following chromosomal anomalies were diagnosed in 125 (17%) fetuses: trisomy 21 (n = 63), trisomy 18 or 13 (n = 21), monosomy X (n = 9), submicroscopic anomalies (n = 11), and other anomalies (n = 22). The mean CM width for euploid fetuses was 2.4 mm (1.13 multiples of the median, MoM). While CM width was significantly increased in trisomy 21 (mean 2.7 mm; 1.23 MoM; p > 0.05), no differences were found in the other anomaly groups. Among the 63 fetuses with trisomy 21, a CM width above the 99th percentile was observed in 23 fetuses (37%). Conclusions: The new reference range for CM width at 11–13 weeks of gestation did not differ from previous studies. In first-trimester fetuses with trisomy 21, CM width appears to be increased, although its value as an ultrasound marker is limited, because of its detection rate of 37%.

In order to contribute to the knowledge of type and frequency of chromosome abnormalities in early pregnancy losses, we analyzed the cytogenetic results from a large series of first trimester miscarriages, using a diagnostic approach with a high success rate and no maternal contamination. A total of 1,119 consecutive chorionic villi samples were obtained before evacuation, and karyotypes were prepared after short-term culture (STC). In 603 samples, a long-term culture (LTC) was also performed. The overall and individual frequencies of the different types of chromosome abnormalities were established, including placental mosaicisms, and their relationship with maternal age and gestational weeks was assessed. An abnormal karyotype was detected in 70.3% of the samples. Single autosomal trisomy was the most frequent abnormality (64.6% of the abnormal cases), followed by triploidy (13.1%) and monosomy X (10.4%). Chromosome rearrangements were found in 5.2%, combined abnormalities in 8.9%, and placental mosaicism in 3.5% of the cases with STC and LTC performed. Individual trisomies behaved differently with respect to maternal age and intrauterine survival. Due to the combination of STC and LTC, our study offers reliable information on the incidence and type of chromosome abnormalities and placental mosaicism in miscarriages and contributes to define the cytogenetic implication in their etiology., This work was partially supported by grants PI11/01841 (IP: A. Sánchez) and PI14/00588 (IP: A. Borrell) from Instituto de Salud Carlos III (Spain) and jointly financed by Fondo Europeo de Desarrollo Regional, Union Europea, Una manera de hacer Europa (FEDER).

A new maternal age-dependent method to estimate absolute excess risks of trisomy 21, either after a previous trisomy 21 (homotrisomy) or after another trisomy (heterotrisomy), is proposed to be added to the estimated risk by conventional screening methods. Excess risk at term for a subsequent trisomy 21 was calculated from midtrimester risks reported by Morris et al., decreasing from 0.49% at 20 years to 0.01% at 46 years at the index pregnancy. Excess risk after a previous uncommon trisomy was derived from data reported by Warburton et al., decreasing from 0.37% at 20 years to 0.01% at 50 years.

Objective To assess fetal cardiac function in first-trimester trisomy-21 fetuses as compared with fetuses with other aneuploidies, euploid fetuses with cardiac defects or isolated increased nuchal translucency (NT) and controls. Methods During a 2.5-year period, NT, ductus venosus (DV) blood flow, diastolic filling time, early filling time, tricuspid flow, tricuspid and mitral valve E/A velocity ratios, left ventricle shortening fraction, left myocardial performance index and fetal heart rate were assessed in fetuses with a crown–rump length between 45 and 84 mm undergoing chorionic villus sampling at our center. Cardiac parameters among study groups were compared with the use of 95% CIs. Results The study population comprised 28 fetuses with trisomy 21, 25 with other aneuploidies, 94 euploid fetuses with abnormal findings (27 with cardiac defects, 31 with other structural anomalies and 36 with isolated increased NT) and 271 controls. Trisomy-21 fetuses showed signs of diastolic dysfunction such as increased DV pulsatility index and E/A ratios together with a higher prevalence of tricuspid regurgitation. However, no differences were found in euploid fetuses with cardiac defects or isolated increased NT. Conclusions No signs of cardiac dysfunction were observed in euploid fetuses with increased NT or cardiac defects, while in trisomy-21 fetuses signs of diastolic dysfunction could be potentially attributed to volume overload. Copyright © 2014 ISUOG. Published by John Wiley & Sons Ltd.

Objective The aim of this study was to assess the role of nuchal translucency (NT) in the prediction of unbalanced translocation in offspring of couples in which one of the parents is a balanced translocation carrier. Material and methods From January 1996 to December 2012, fetal NT was measured before chorionic villus sampling in 86 pregnancies referred because of parental balanced translocation. Results No significant differences in pregnancy characteristics and in NT expressed in millimetres or in multiples of the median (MoMs) were observed between the 41 fetuses with a normal karyotype [1.72 mm, 95% confidence interval (CI): 1.49–1.96; 1.14 MoM; 95% CI: 1.01–1.26], the 38 fetuses with balanced translocations (1.78 mm, 95% CI: 1.44–2.12; 1.22 MoM; 95% CI: 1.01–1.43) and the 7 fetuses with unbalanced translocations (2.21 mm, 95% CI: 1.33–3.09; 1.59 MoM; 95% CI: 0.72–2.45). The proportions of fetuses with NT above 95th centile in the three groups were 9.1% in fetuses with normal karyotype, 18.4% in balanced translocations and 28.6% in unbalanced translocations, not significantly different. Conclusion Although a trend to an increased NT was observed in fetuses with unbalanced translocation, no significant differences were reached. According to our results, a normal NT evaluation should not preclude the performance of CVS in pregnancies of balanced translocation parents. © 2014 John Wiley & Sons, Ltd.

Objective To investigate whether increased nuchal translucency (NT) in fetuses with a crown–rump length (CRL) below 45 mm needs to be re-evaluated at a later stage, or whether the early NT measurement can be used effectively as an aneuploidy marker. Methods This was a prospective cohort study including all singleton fetuses with a CRL between 28 and 44 mm, scanned in our center during 2002–2012. The CRL, NT, fetal karyotype (when available) and pregnancy outcome were recorded. NT reference ranges were constructed using the Lambda-Mu-Sigma (LMS) method in non-referred pregnancies after exclusion of chromosomal anomalies. The 95th percentile was used to calculate detection rates for chromosomally abnormal fetuses. Results NT was successfully measured in 643 of 672 fetuses with a CRL of 28–44 mm. Subsequent cytogenetic analysis revealed 11 cases of trisomy 21, 14 cases of trisomy 13 or 18, three cases of monosomy X, three sex trisomies, three triploidies and 12 balanced anomalies. NT was above the 95th percentile in 64% of the fetuses with trisomy 21, in 71% with trisomy 13 or 18 and in all three cases of monosomy X. Conclusion NT appears to be useful as a marker for the early detection of fetal trisomies at 9–10 weeks' gestation (28–44 mm CRL). Copyright © 2013 ISUOG. Published by John Wiley & Sons Ltd.

Resumen La amniocentesis es un procedimiento de diagnostico prenatal invasivo de segundo trimestre, descrito inicialmente en 1966 por Steele y Berg. Consiste en la introduccion de una aguja espinal a traves de la pared abdominal, la pared uterina y la cavidad amniotica bajo guia ecografica continua, de forma que se pueda aspirar una muestra del liquido amniotico que envuelve el feto y que contiene celulas de origen fetal. La amniocentesis se realiza a partir de las 16 semanas de gestacion y en el liquido amniotico se pueden realizar estudios cromosomicos, bioquimicos, moleculares o microbiologicos. El procedimiento conlleva un riesgo de perdida fetal de aproximadamente el 0,5% cuando se realiza en el segundo trimestre, despues de la fusion de la membrana amniotica con el corion, ademas de un riesgo menor de otras complicaciones, como la perdida de liquido amniotico (0,3%), hemorragia placentaria, infeccion intraamniotica, hematoma de la pared abdominal o traumatismo fetal. A medida que la experiencia internacional se acumula, se van determinando los factores que pueden ayudar a mejorar aun mas la seguridad y la facilidad tecnica del procedimiento. Hemos descrito un nuevo metodo de aspiracion para realizar la amniocentesis que emplea un Vacutainer® (BD Vacutainer Systems, Plymouth, Reino Unido), para obtener un vacio continuo cuando la aguja ya esta insertada dentro de la cavidad amniotica, en contraste con la tecnica estandar de aspiracion mediante jeringa o «pistola» en que las presiones negativas son discontinuas. Sin embargo, la tecnica clasica con aspiracion con jeringa continua siendo valida y la mas utilizada. Basados en la experiencia de 30 anos y en el volumen de procedimientos realizados en nuestro centro (mas de 20.000 procedimientos invasivos realizados), junto con una revision de la bibliografia publicada hasta la fecha, hemos planteado una guia practica actualizada para la realizacion de la amniocentesis.

Objective To assess the best method of combining fetal nuchal translucency (NT) and ductus venosus (DV) blood flow measurements in the detection of major cardiac defects in chromosomally normal fetuses during the first-trimester scan. Methods During an 8-year period NT and DV blood flow were routinely assessed at 11–14 weeks' gestation. Only chromosomally normal singleton pregnancies were included in the study. When a cardiac defect was suspected, or when increased fetal NT and/or absent or reversed (AR) A-wave in the DV was observed, early fetal echocardiography was offered. Data on routine second- and third-trimester scans, neonatal follow-up or postmortem examination were obtained from hospital records. The detection and false-positive rates for all major cardiac defects were calculated for several screening strategies, including: NT or DV pulsatility index for veins (DV-PIV) above a fixed normal centile; AR A-wave; risk based on NT and DV-PIV or A-wave velocity above a fixed normal centile; and combinations of these strategies. Results The study population included 37 chromosomally normal fetuses with a major cardiac defect and 12 799 unaffected pregnancies. Fetal NT above the 95th or the 99th centile and AR A-wave was observed in 40, 27 and 39% of the fetuses with major cardiac defects, respectively. A 47% detection rate with a 2.7% false-positive rate was obtained when AR A-wave or NT above the 99th centile was used as the selection criterion. Conclusions Half of major fetal cardiac defects could be detected in the first trimester if NT and DV Doppler are used to select 2.7% of the general pregnant population for extended fetal echocardiography. Copyright © 2013 ISUOG. Published by John Wiley & Sons Ltd.

The patient was referred for prenatal diagnosis due to the sonographic finding of a polymalformed male fetus, and an amniocentesis was performed before termination of pregnancy. The pathological study of the placenta did not show morphological alterations. In her next pregnancy, sonographic examination disclosed a missed abortion with a visible embryo, and a chorionic villi sample was obtained for cytogenetic analysis before evacuation. Macroscopic examination of the villi sample did not reveal molar vesicular appearance. QF-PCR and cytogenetic analyses were performed on amniotic fluid (first pregnancy) and chorionic villi samples (second pregnancy). A 69,XXY and 92,XXXY karyotype was found, respectively. QF-PCR results disclosed 2 maternal and 1 paternal alleles in the first pregnancy (digynic triploidy), and double maternal and double paternal contribution to the tetraploid pregnancy. Among the few reported cases of 92,XXXY tetraploidy, those associated with partial moles show a PPPM genotype (3 paternal and 1 maternal alleles), and the only case with a PPMM genotype was found in a spontaneously aborted fetus similar to our case. We are not aware of other cases with combination of a digynic triploid pregnancy and a tetraploid pregnancy with a PPMM contribution. Our case adds evidence to the influence of the balance between paternal and maternal genomic doses on the phenotype.

The aim of this study was to assess the performance of first-trimester combined screening when replacing the chronological maternal age by Anti-Mullerian hormone (AMH) and antral follicle count (AFC)-derived ovarian ages, as the background risk in trisomy risk estimation. A total of 639 pregnant women who completed first-trimester combined screening together with AMH and AFC determination were included. Trisomy risks were estimated based on three distinct ‘maternal ages' as a-priori risk (chronological age, AMH- and AFC-derived ovarian age). The screening performance was assessed using three different approaches: received operator curve; detection rate and false positive rates for a fixed 1/250 threshold; and detection rates for a fixed 3% false positive rate. A non-significant trend was shown for AMH-derived age for both an increased area under the curve (0.986 versus 0.979) and an increased detection rate (from 83% to 100%) for a 1/250 risk threshold. For a 3% false-positive rate, a non-significant trend for increased detection with the use of both AMH- and AFC-derived ovarian ages was observed (from 67% to 83%). These results indicate that, although ovarian derived ages seem to potentially reflect a more precise background risk for fetal trisomies, the improvement in screening performance is only residual.

Resumen Objetivo Evaluar la aplicacion clinica de los metodos no invasivos en el manejo de la isoinmunizacion, durante el periodo de 2006-2010. Sujetos y metodos Se estudiaron 70 gestaciones con riesgo de anemia fetal en las que se realizo el estudio Doppler de la velocidad sistolica de la arteria cerebral media (VS-ACM). Se comparo la eficacia de la VS-ACM despues de una, 2 o 3 transfusiones intrauterinas. El genotipado fetal RHD en sangre materna se realizo en las gestaciones seguidas en nuestro centro. Resultados Se practico cordocentesis en 22 de gestaciones y en 20 se practico transfusion intrauterina. Las tasas de deteccion y de falsos positivos de la VS-ACM en la prediccion de anemia fetal moderada o severa fueron del 89 y el 15% en gestaciones sin transfusion previa, del 100 y el 41% en los casos con una transfusion previa y del 40 y el 24% cuando se practicaron mas de una transfusion. Conclusiones La VS-ACM mantiene una sensibilidad alta en una transfusion previa aunque su especificidad disminuye.

Objective To assess a new contingent screening strategy for Down syndrome completed in the first trimester. Methods First-trimester screening combining nuchal translucency thickness measurement and assessment of serum analytes (combined test) was offered to pregnant women who presented for prenatal care during the first trimester to nine health centers and community hospitals in the area served by the Catalan Public Health Service. If an intermediate risk (1/101–1/1000) for Down syndrome was identified, women were referred to the Hospital Clinic Barcelona for risk reassessment that included the use of secondary ultrasound markers (nasal bone, ductus venosus blood flow and tricuspid flow). Intermediate-risk women were divided into two subgroups for further analysis: high-intermediate risk (1/101–1/250) and low-intermediate risk (1/251–1/1000). We compared feasibility and efficacy of both combined and contingent screening strategies. Results The combined test, the first screening stage, was performed in 16 001 pregnant women, of whom 1617 (10.1%) were found to have an intermediate risk. Further division of this group showed that 1.8% (n = 289) of women were at high-intermediate risk and 8.3% (n = 1328) at low-intermediate risk. The contingent screening strategy significantly reduced the false-positive rate, from 3.0% to 1.3–1.8% (P < 0.001), without affecting the detection rate (which was 75–79% and 76%, with and without the contingent screening strategy, respectively). However, only 45% of intermediate-risk patients underwent the second screening step due to a preference among high-intermediate-risk (1/101–1/250) women for invasive testing and to low uptake among low-intermediate-risk (1/251–1/1000) women. Conclusions The proposed first-trimester contingent strategy reduces the screen false-positive rate without impacting on the detection rate of Down syndrome. The low compliance observed in our study may prevent its use in certain populations. Copyright © 2012 ISUOG. Published by John Wiley & Sons, Ltd.

Objectives To determine the sensitivity of first-trimester ultrasound for diagnosing different structural anomalies in chromosomally normal pregnancies, and to establish the role of aneuploidy markers in the detection of abnormalities. Methods This was a retrospective study of chromosomally normal singleton pregnancies with an 11–14-week scan performed in our center during 2002–2009. The ultrasound examination included an early fetal anatomy survey and assessment of nuchal translucency, ductus venosus blood flow and nasal bone. Results Among 13 723 scanned first-trimester pregnancies with no genetic anomalies and complete follow-up, 439 fetuses (3.2%) were found to present with structural anomalies (194 with major anomalies and 245 with only minor anomalies). Forty-nine per cent of major structural anomalies were detected during the first-trimester scan, the highest rates corresponding to acrania (17/17), holoprosencephaly (three of three), hypoplastic left heart syndrome (10/10), omphalocele (six of six), megacystis (seven of eight) and hydrops (eight of nine). Higher than expected detection rates were obtained for skeletal (69%) and cardiac (57%) defects, coincidentally showing the highest presence of an increased nuchal translucency or abnormal ductus venosus blood flow (38% and 52%, respectively). The finding of an absent nasal bone did not appear to be associated with structural defects. Conclusion About half of major structural abnormalities can be diagnosed in the first trimester. Increased nuchal translucency or abnormal ductus venosus blood flow appear to be associated with cardiac and skeletal defects and may facilitate early detection. Copyright © 2012 ISUOG. Published by John Wiley & Sons, Ltd.

Resumen La anticipacion del cribado de las aneuploidias fetales al primer trimestre ha requerido implementar tecnicas diagnosticas en este momento de la gestacion. La biopsia de vellosidades coriales (BVC) es un procedimiento diagnostico invasivo en Medicina Materno-Fetal, que consiste en la obtencion de vellosidades coriales para estudio citogenetico, molecular o bioquimico. Existen dos vias para la realizacion de la BVC, la transcervical y la transabdominal. La preferencia por una de las dos vias se ha basado historicamente en factores como son la localizacion placentaria, paridad, peso materno, preferencias del operador, etc. En nuestra institucion pasamos a utilizar la via transcervical de manera casi exclusiva, con resultados ventajosos para la gestante y el laboratorio. Todo ello, sin diferencias en cuanto a la tasa de perdida gestacional u otras complicaciones. A pesar de 3 decadas de uso de la BVC transcervical, existe poco consenso en cuanto a su tecnica y las guias clinicas especificas para su realizacion son escasas. Aprovechando la experiencia y el volumen acumulado de procedimientos realizados en nuestro centro, hemos planteado una guia clinica eminentemente practica para la realizacion de BVC transcervical.

Objectives To assess the value of ductus venosus blood flow (expressed as pulsatility index, DVPI) in antenatal Down's syndrome screening when used with the Combined and Integrated tests. Methods DVPI measurements between 10 and 13 weeks’ gestation in 66 Down's syndrome and 7184 unaffected pregnancies were collected from women attending the Hospital Clinic, Barcelona, for antenatal care from 1999 to 2007 and combined with the Serum Urine and Ultrasound Screening Study (SURUSS) data to model screening performance, safety and cost-effectiveness of the screening tests with and without DVPI. Results The median DVPI multiple of the normal median in Down's syndrome pregnancies was 1.55 (95% CI 1.36–1.73). As a single screening marker without using maternal age, DVPI has a 62% detection rate for a 5% false-positive rate. At a 90% detection rate (first trimester measurements at 11 weeks’ gestation) the addition of DVPI reduced the false-positive rate of the Combined test from 8.5% to 4.6% and the Integrated test from 2.0% to 1.1%, with a corresponding reduction in fetal losses from diagnostic procedures. There was no material loss of cost-effectiveness. Conclusion Addition of DVPI measurements to the Combined and Integrated tests substantially improves the efficacy and safety of antenatal Down's syndrome screening.

First trimester screening for fetal aneuploidies has made the implementation of diagnostic techniques essential. Chorionic villus sampling (CVS) is the method of choice for obtaining chorionic villi for molecular and cytogenetic analysis in the first trimester. Two techniques have been developed, a transcervical and a transabdominal. The selection criteria have been based historically on factors, such as placental location, parity, maternal weight and preference of the operator. In our institution, we developed an elevated level of expertise in the field of transcervical approach, resulting in good quality of samples and comparable fetal loss rate to other approaches. Despite three decades of transcervical CVS performance, little consensus in terms of its technique and clinical guidelines exists. Considering the expertise and the volume of procedures performed at our center, we suggest a practical clinical guideline for transcervical CVS.

Objective To describe the false-positive diagnoses of prenatal ultrasound screening of fetal structural anomalies. Methods Pregnancies with fetal structural anomalies either detected prenatally in our center or referred to us, were registered, evaluated, and followed-up prospectively by a multidisciplinary Congenital Defects Committee. After postnatal follow-up was completed, cases were assigned as true positives, false positives or false negatives and categorized by anatomical systems. Pregnancies referred with a nonconfirmed suspicion of anomaly were not included. The false-positive diagnoses were analyzed. Results From 1994 to 2004, 903 new registry entries of fetuses structurally abnormal at ultrasound with a complete follow-up were included in the Committee database. There were 76 false positives, accounting for 9.3% of all the prenatally established diagnoses. The urinary tract anomalies were the most frequent false-positive diagnoses found (n = 25; accounting for 8.7% of the urinary tract defects), but the genital anomalies showed the higher rate of no confirmation (n = 5; 15.2%). The specific anomalies most commonly not confirmed were renal pyelectasis (n = 9), cerebral ventriculomegaly (n = 9), abdominal cysts (n = 7) and short limbs (n = 7). Conclusion Several prenatally diagnosed anomalies would benefit from prudent counseling, because they may be normal variants or transient findings. Copyright © 2007 John Wiley & Sons, Ltd.

Resumen Objetivo Evaluar los resultados de la transfusion fetal intravascular en el tratamiento de la isoinmunizacion, durante el periodo 1990-2003. Sujetos y metodos Se ofrecio una cordocentesis para realizar un hemograma fetal a las gestantes isoinmunizadas con sospecha de anemia fetal significativa. Se practico transfusion intrauterina cuando el valor del hematocrito fetal fue inferior a –2 desviaciones estandar para la edad gestacional. Las transfusiones se repitieron aproximadamente cada 3 semanas hasta la semana 34-35. Resultados Se practico una cordocentesis en 32 gestaciones, en 11 (34%) de las cuales no se objetivo una anemia fetal significativa de acuerdo con los criterios establecidos. En 19 gestaciones se realizaron un total de 50 transfusiones entre las 21 y 35 semanas. No se observo ninguna perdida fetal espontanea. A los 0-13 anos de vida, todos los ninos presentan una evolucion correcta para su edad. Conclusion La transfusion intravascular fetal es una tecnica efectiva en el tratamiento prenatal de la anemia fetal con resultados favorables a largo plazo.

Nuchal translucency (NT) is defined as the accumulation of subcutaneous fluid in the nuchal region of the fetus at 11–14 weeks. Its measurement in order to modify the previous background risk has been proved to be able to detect around 70% of trisomy 21 pregnancies (for a 5% fixed positive rate). When affected fetuses dying before 20 weeks are excluded, detection rate may decrease to 60%. Given that appropriate training of sonographers and adherence to a standard technique for the measurement of NT is of paramount importance to reduce variability, the Fetal Medicine Foundation has established a certification process. Fetal nuchal edema displayed at 15–20 weeks was described as enlarged nuchal skinfold, and is a less sensitive but more specific marker than nuchal translucency. Webbing of the neck in infants with trisomy 21 may be envisaged as the remainder of nuchal distension.

Objective To assess the potential value of ductus venosus Doppler studies in the detection of fetal aneuploidy on measurement of nuchal translucency. Methods The pulsatility index for veins (PIV) and the lowest velocity during atrial contraction (A-wave) were determined in the fetal ductus venosus in 3382 consecutive pregnancies at 10 to 14 weeks and studied from December 1996 to December 2001. Nuchal translucency was also measured. The population studied included 1664 pregnancies at high risk and 1718 at low risk for fetal aneuploidy. Results In relation to the prenatal detection of trisomy 21, the ductus venosus PIV was increased in 75% (36/48), the A-wave was decreased in 58% (28/48), and nuchal translucency was enlarged in 81% (39/48) of the trisomy 21 fetuses [71% (22/31) when nuchal translucency referrals were excluded]. The corresponding figures for trisomies 18 and 13 were 71, 58 and 83%, respectively, being 33, 33 and 33% for other unbalanced anomalies. Conclusion There is a high proportion of fetuses with trisomies 21, 18 and 13 (around 75%) in which the ductus venosus PIV is increased (above the 95th percentile) at 10 to 14 weeks, this proportion being similar to that observed for increased nuchal translucency measurement. Copyright © 2003 John Wiley & Sons, Ltd.

Objective To assess the role of two ovarian reserve markers, antimullerian hormone (AMH) and antral follicle count (AFC), as markers of the background risk for fetal trisomy. Design Prospective study. Setting Tertiary referral hospital. Patient(s) Assessment was carried out either in ongoing pregnancies or miscarriages in our center. Intervention(s) AFC was assessed transvaginally during a routine (11–13 weeks) or referral scan. AMH was determined either during the first-trimester maternal serum markers assessment or in cases referred for chorionic villi sampling after the invasive procedure. Main Outcome Measure(s) AMH reference ranges were constructed according to maternal age, and AMH- and AFC-derived ovarian ages were compared among three different cytogenetic groups (normal karyotype, autosomal trisomies, and other chromosomal anomalies) in both ongoing pregnancies and miscarriages. Result(s) In autosomal trisomies, the median AFC-derived ovarian age was 3–5 years above the median maternal age. No differences were observed between AMH-derived ovarian age and maternal age. Conclusion(s) AFC-derived ovarian biologic age reflects a more precise background risk for fetal aneuploidy that is not observed for AMH-derived age.

Study question Can antral follicle count (AFC) measured during pregnancy be used as a marker of ovarian age to assess the background risk of fetal aneuploidy? Summary answer AFC was lower than expected according to maternal chronological age in trisomic pregnancies; therefore ovarian age could potentially reflect a more precise background risk of fetal aneuploidy screening. What is known already The decline in a woman's reproductive function is determined by a decline in the ovarian follicle pool and the quality of oocytes. The quantitative status of ovarian reserve can be indirectly assessed by AFC, but the role of AFC as an aneuploidy risk marker in pregnant women has not been assessed yet. Study design, size, duration Our study comprised a prospective cohort including 1239 singleton pregnancies scanned before 14 weeks in our center during a 14-month period. Participants/materials, setting, methods Reference ranges for AFC were constructed using 812 spontaneously conceived, chromosomally normal singleton ongoing pregnancies using the Lambda-Mu-Sigma method. The study population (n = 934) included 19 pregnancies with viable autosomal trisomies (trisomies 21, 18 and 13), 17 non-viable autosomal trisomies (other than 21, 18 or 13), 7 monosomies X, 1 sex trisomy and 3 triploidies (total n = 47 with chromosomal abnormalities). AFC in chromosomally abnormal pregnancies was plotted against the reference ranges. AFC multiple of the median was calculated according to the median AFC obtained by each year of age. Main results and the role of chance Sixty-eight percent of women carrying a pregnancy with viable trisomies and 65% with non-viable trisomies presented an AFC below the 50th percentile. The median ovarian age in viable trisomies and non-viable trisomies was estimated to be 3 and 6 years above than median maternal age, respectively. However, the median ovarian age in monosomies X and triploidies was not higher than median maternal age. Limitations, reasons for caution We did not assess the intra- and inter-observer reliability, or use specific three-dimensional analysis which may have advantages over our two-dimensional study. In clinical practice, a drawback for assessing AFC during pregnancy is that transvaginal ultrasound is needed at the 11- to 13-week scan, when the transabdominal approach is used most commonly. Furthermore identifying ovaries by ultrasound during pregnancy could be challenging. Wider implications of the findings Considering that AFC reflects ovarian aging, this 'ovarian biological age' could potentially reflect a more precise background risk of fetal aneuploidy. Study funding/competing interest(s) This study was supported by PI 11/00685. Instituto de Salud Carlos III. Fondo de Investigacion Sanitaria. No competing interests declared.

Amniocentesis is a technique for withdrawing amniotic fluid from the uterine cavity using a needle, via a transabdominal approach and under continuous ultrasound guidance, in order to obtain a sample of fetal exfoliated cells, transudates, urine or secretions. It can be performed from 16 weeks of pregnancy onwards, with various chromosomal, biochemical, molecular and microbial studies being performed on the amniotic fluid sample. The most common reasons for the procedure are to enable prenatal diagnosis of chromosomal abnormalities, single gene disorders, fetal infection and intra-amniotic inflammation, as well as to assess fetal lung maturity and blood or platelet type. The procedure has a risk of fetal loss of approximately 0.5% (range, 0.06–1%)1 when performed in the second trimester, after the amniotic membrane has fused with the chorion; there is also a risk of amniotic fluid leakage (approximately 0.3% of cases) and other rare complications, such as placental hemorrhage, intra-amniotic infection, abdominal wall hematoma and fetal lesion. There is an important lack of good-quality evidence to support most recommendations for the procedure, and a recent review suggested that operators should use those methods and technique modifications with which they are most familiar when performing an amniocentesis2. The aim of this summary article and the full version, included as supplementary material online, is to describe the amniocentesis technique, presenting a practical guideline for its performance. We also describe the use of a Vacutainer® (BD Vacutainer Systems, Plymouth, UK) aspiration system in order to produce a continuous vacuum for amniotic fluid aspiration as an alternative to using manually operated syringes.

The aim of this study was to assess the role of nuchal translucency (NT) in the prediction of unbalanced translocation in offspring of couples in which one of the parents is a balanced translocation carrier.From January 1996 to December 2012, fetal NT was measured before chorionic villus sampling in 86 pregnancies referred because of parental balanced translocation.No significant differences in pregnancy characteristics and in NT expressed in millimetres or in multiples of the median (MoMs) were observed between the 41 fetuses with a normal karyotype [1.72 mm, 95% confidence interval (CI): 1.49-1.96; 1.14 MoM; 95% CI: 1.01-1.26], the 38 fetuses with balanced translocations (1.78 mm, 95% CI: 1.44-2.12; 1.22 MoM; 95% CI: 1.01-1.43) and the 7 fetuses with unbalanced translocations (2.21 mm, 95% CI: 1.33-3.09; 1.59 MoM; 95% CI: 0.72-2.45). The proportions of fetuses with NT above 95th centile in the three groups were 9.1% in fetuses with normal karyotype, 18.4% in balanced translocations and 28.6% in unbalanced translocations, not significantly different.Although a trend to an increased NT was observed in fetuses with unbalanced translocation, no significant differences were reached. According to our results, a normal NT evaluation should not preclude the performance of CVS in pregnancies of balanced translocation parents.

Objective: To assess the feasibility of nasal bone (NB), ductus venosus (DV) and tricuspid flow (TF) at the 11-13 weeks' scan, calculate likelihood ratios for each of the markers and evaluate their efficacy in expanded and contingent screening strategies for Down syndrome. Material and Methods: NB, DV and TF were assessed in 11,261 singleton fetuses undergoing first trimester combined screening. For each marker, Down syndrome detection rate (DR), false positive rate (FPR), positive, negative and isolated likelihood ratios (PLR, NLR and iLR) were calculated. Likelihood ratios were multiplied to the combined test risk either to the entire population or to the intermediate risk group (expanded and sequential strategies, respectively). Results: Down syndrome was diagnosed in 101 pregnancies. Feasibility for marker assessment ranged from 71 to 97%, DRs for isolated markers from 20 to 54% and FPRs from 1.3 to 5.3%. PLR ranged from 10 to 15, NLR from 0.5 to 0.8 and iLR from 3.9 to 5.6. When ultrasound markers were added to both strategies, a significant FPR reduction was observed. Conclusion: The application of NB, DV and TF likelihood ratios to the combined test risk, either in an expanded or contingent strategy, result in a FPR reduction.

Study question Is there any effect of maternal age on chromosomal anomaly rate and spectrum in recurrent miscarriage? Summary answer There was no significant difference in the chromosome abnormality rate between sporadic and recurrent miscarriage but the chromosome abnormality rate increased significantly with maternal age. What is known already About 50-70% of non-recurrent miscarriages occur because of a chromosomal anomaly, but no agreement about the effect of either maternal age or the number of previous miscarriages on the chromosomal anomaly rate has been reached. Study design, size, duration A retrospective cohort of 353 miscarriages successfully karyotyped in the same center between 2002 and 2011, grouped according to the number of miscarriages and maternal age. Participants/materials, setting, methods Among the 353 women, 153 were below 35 years (73 with sporadic, 48 with two and 32 with recurrent miscarriage) and 200 were 35 years or more (81 with sporadic, 55 with two and 64 with recurrent miscarriage). The chromosomal anomaly rate and the anomaly spectrum were compared between sporadic and recurrent miscarriage, within the two maternal age groups, using the chi-square test and the Bonferroni correction for all the P-values. Risk of chromosomal anomaly was estimated for maternal age, number of miscarriages and previous live births by multivariate binary logistic regression analysis. Main results and the role of chance Sporadic and recurrent miscarriage did not show significantly different chromosomal anomaly rates (68 versus 60%) and maternal age was the only statistically significant predictor of the chromosomal anomaly risk we identified. Some trends were observed in the chromosomal anomaly spectrum when sporadic was compared with recurrent miscarriage: recurrent miscarriage exhibited a decrease in viable trisomies (37 versus 11%) and an increase in non-viable trisomies (38 versus 57%) in women >35 years, together with an increase in unbalanced structural anomalies (4.9 versus 29%) in younger women. Limitation, reasons for caution The mixed origin of our study population, and the limited number of recurrent miscarriages, particularly in the younger group, limits statistical power to detect differences. Wider implications of the findings The most commonly observed chromosomal anomaly type in recurrent miscarriage depends on maternal age: non-viable autosomal trisomies in older women and unbalanced structural anomalies in younger women. When a chromosomal anomaly is identified as the cause of miscarriage, additional maternal evaluation may be avoided. Study funding/competing interests No competing interests declared.

Conventional tissue culturing and karyotyping of spontaneous abortions has limitations such as culture failure, external contamination and selective growth of maternal cells. Molecular cytogenetic techniques such as FISH, QF-PCR, and CGH allow diagnosis on uncultured cells but are also limited as to the spectrum of cytogenetic abnormalities detected. We describe the cytogenetic findings in a series of 116 first trimester arrested pregnancies, obtained through chorionic villi sampling (CVS) and semi-direct analysis that avoids some of the long-culture pitfalls such as maternal contamination, and compare our results with those that would have been obtained theoretically using molecular cytogenetic techniques. Samples were obtained by transcervical CVS from women with a diagnosis of missed abortion, most of them referred for cytogenetic prenatal diagnosis. Cytogenetic analysis was performed using semi-direct technique. A karyotype was obtained in 103 cases. Eighty-two abnormal karyotypes were found (80%), including 12 triploidies, 10 monosomies, 61 trisomies, and 9 structural abnormalities; a double abnormality being present in 10 cases. Between 10% and 50% of our abnormal results would have been missed using the most common molecular cytogenetic techniques. Semi-direct analysis of CVS may still be considered as a comprehensive, reasonably rapid, cost-effective and reliable method for detecting the broadest spectrum of chromosome abnormalities in missed abortions.

Objective To assess second-trimester screening for trisomy 21 by combining ultrasound nuchal fold (NF) measurement with maternal serum biochemistry. Methods NF, maternal serum α-fetoprotein (AFP) and free β-human chorionic gonadotropin (β-hCG) were determined concurrently at 14–19 weeks’ gestation in a study population comprising 1813 women with singleton pregnancies, including 1257 unselected women undergoing serum screening for trisomy 21 (1999–2002), and 556 high-risk pregnancies prior to amniocentesis (2003–2005), 402 of whom had positive serum screening tests. The results were expressed in multiples of the gestation-specific normal median (MoMs). Results There were 1799 unaffected singleton pregnancies, and their NF values approximately fitted a log Gaussian distribution over a wide range. There was a weak but statistically significant correlation between log NF and log AFP (r =− 0.069, P < 0.005) and the correlation coefficient between log NF and log free βhCG was even smaller and not statistically significant (r = 0.038, P = 0.11). Among the seven trisomy 21 pregnancies, the median NF level was 1.53 MoM (geometric mean 1.75 MoM), a highly statistically significant increase compared with unaffected pregnancies (P < 0.0001, onetail Wilcoxon Rank Sum Test). In pregnancies referred because of positive serum screening tests (391 unaffected, seven cases of trisomy 21, one of monosomy X and three other chromosomal anomalies) the use of NF to modify the serum screening risk would have reduced the invasive procedures in unaffected pregnancies by 46% without affecting the detection rate of trisomy 21 or other anomalies. Statistical modeling predicted that adding NF to AFP and free β-hCG would increase detection more than would adding unconjugated estriol as well as inhibin-A, an analyte that is difficult to measure with precision. Conclusions The addition of NF measurement to second-trimester biochemical markers improves screening performance, and could overcome drawbacks in the implementation of inhibin-A assay in clinical practice. Copyright  2007 ISUOG. Published by John Wiley & Sons, Ltd.

To assess the potential value of ductus venosus Doppler studies in the detection of fetal aneuploidy on measurement of nuchal translucency.The pulsatility index for veins (PIV) and the lowest velocity during atrial contraction (A-wave) were determined in the fetal ductus venosus in 3382 consecutive pregnancies at 10 to 14 weeks and studied from December 1996 to December 2001. Nuchal translucency was also measured. The population studied included 1664 pregnancies at high risk and 1718 at low risk for fetal aneuploidy.In relation to the prenatal detection of trisomy 21, the ductus venosus PIV was increased in 75% (36/48), the A-wave was decreased in 58% (28/48), and nuchal translucency was enlarged in 81% (39/48) of the trisomy 21 fetuses [71% (22/31) when nuchal translucency referrals were excluded]. The corresponding figures for trisomies 18 and 13 were 71, 58 and 83%, respectively, being 33, 33 and 33% for other unbalanced anomalies.There is a high proportion of fetuses with trisomies 21, 18 and 13 (around 75%) in which the ductus venosus PIV is increased (above the 95th percentile) at 10 to 14 weeks, this proportion being similar to that observed for increased nuchal translucency measurement.