Clinical article: screening for trisomy 13 using traditional combined screening versus an ultrasound-based protocol.

AIMS: To compare the screening capability of ultrasonography in detecting trisomy 13 (T13) using a multiparameter sonographic protocol (NT+) with a classical combined screening test (CST) protocol. METHODS: The project was a prospective, multicenter study based on a nonselected mixed-risk population of women referred for a first-trimester screening examination. Each subject was offered a choice between either the gold standard, traditional combined screening test (CSG arm) or the ultrasound-based screening protocol (USG arm). General and MA-based screening performances were checked. RESULTS: The study population comprised 20,887 pregnancies: 12,933 in the CSG arm, including 27 cases of T13, and 7954 in the USG arm, including 30 cases of T13. The DR for T13 was higher in the CSG arm than in the USG arm for all tested cutoff points: 1/50 (88.5 versus 63.3%, respectively), 1/100 (88.5 versus 70%, respectively) and 1/300 (92.3 versus 83.3%, respectively). Using the ROC curves for fixed FPRs of 3 and 5%, the T13 detection rate in our study reached 90 and 93%, respectively, in the USG arm and 92 and 96%, respectively, in the CSG arm. MA influenced the T13 screening performance in the USG arm and reduced the DR in patients <31 years. Such influence was not detected in the CSG arm. CONCLUSIONS: Classic CST was more effective in detecting T13 than the ultrasound-only approach. However, the recommended cutoff of 1/50 showed unsatisfactory results for both traditional CST and the multiparameter sonographic test we proposed.

Placenta mórbidamente adherente asociada a malformaciones congénitas: reporte de caso / Morbidly adherent placenta associated with congenital malformations: a case report

INTRODUCCIÓN: Las alteraciones en la placentación son causa importante de morbilidad materna y neonatal y, en ocasiones, de mortalidad. La literatura científica menciona la posible asociación entre acretismo placentario y alteraciones en los parámetros bioquímicos para aneuploidía, sin descripciones de casos en que coincidan estos dos hallazgos. OBJETIVO: Este es un reporte de caso de una gestante con placenta percreta y producto con trisomía 13 REPORTE DE CASO: Gestante de 34 años, gesta 4 cesáreas 2, abortos 1, vivos 2, con embarazo de 20.4 semanas, sin antecedentes de importancia, con hallazgos en ecografía de iii nivel de alteraciones morfológicas en el sistema nervioso central, onfalocele, malformación cardiaca y deformidades en miembros. Con doppler de placenta que evidencia placenta mórbidamente adherida variedad percreta; hallazgos ecográficos confirmados con el estudio anatomopatológico. CONCLUSIONES: La trisomía 13 es una condición genética que debido a las múltiples malformaciones asociadas se considera incompatible con la vida, la placenta mórbidamente adherida se ha asociado con morbimortalidad neonatal y fetal, la no evidencia en la literatura de estas dos condiciones asociadas puede ser debido a la interrupción temprana de las gestaciones en las que se confirma el primer diagnóstico.

BACKGROUND: Alterations in placentation are an important cause of maternal and neonatal morbidity and, sometimes, deaths. The scientific literature mentions the possible association between placental accreta and alterations in the biochemical parameters for aneuploidy, without descriptions of cases in which these two findings coincide. OBJECTIVE: This is a case report of a pregnant woman with placenta percreta and trisomy 13, in which an ultrasound and pathological analysis were made. The use of keywords, in different databases, did not yield information that directly comply with these associations. CASE REPORT: A 34-year-old pregnant woman, G4C2A1V2 with a 20.4-week pregnancy, without significant medical records, with findings at III level ultrasound of morphological alterations of the central nervous system, omphalocele, cardiac malformation and limb deformities. Also, with placental Doppler that evidences morbidly adhered placenta variety percreta; ultrasound findings confirmed with the pathological study. CONCLUSION: The morbidly adhered placenta has been associated with neonatal and fetal mortality, in which some of the identified causes of fetal death are congenital anomalies. This way this case report allows for the first time to describe the association of placental accreta with aneuploidy, type trisomy 13, demonstrated by the morphological alterations of the pathological and karyotype study.

Is there still a role for nuchal translucency measurement in the changing paradigm of first trimester screening?

OBJECTIVES: To give an overview of the genetic and structural abnormalities occurring in fetuses with nuchal translucency (NT) measurement exceeding the 95th percentile at first-trimester screening and to investigate which of these abnormalities would be missed if cell-free fetal DNA (cfDNA) were used as a first-tier screening test for chromosomal abnormalities. METHODS: This is a national study including 1901 pregnancies with NT≥95th percentile referred to seven university hospitals in the Netherlands between 1 January 2010 and 1 January 2016. All cases with unknown pregnancy outcome were excluded. Results of detailed ultrasound examinations, karyotyping, genotyping, pregnancy and neonatal outcomes, investigation by a clinical geneticist and post-mortem investigations were collected. RESULTS: In total, 821 (43%) pregnancies had at least one abnormality. The rate of abnormalities was 21% for fetuses with NT between 95th and 99th percentile and 62% for fetuses with NT≥99th percentile. Prevalence of single-gene disorders, submicroscopic, chromosomal and structural abnormalities was 2%, 2%, 30% and 9%, respectively. CONCLUSION: Although cfDNA is superior to the combined test, especially for the detection of trisomy 21, 34% of the congenital abnormalities occurring in fetuses with increased NT may remain undetected in the first trimester of pregnancy, unless cfDNA is used in combination with fetal sonographic assessment, including NT measurement.

Measurement of inferior facial angle and prefrontal space ratio in first trimester fetuses with aneuploidies: a retrospective study.

Objective To determine whether the measurement of inferior facial angle (IFA) and prefrontal space ratio (PFSR) in two-dimensional (2D) ultrasound images in the first trimester of pregnancy is reliable and to describe these markers in normal and aneuploid fetuses. Methods IFA and PFSR were measured in stored 2D midsagittal images of 200 normal and 140 aneuploid fetal profiles between 11 + 0 and 13 + 6 weeks of gestation. Limits of agreement (LOAs) and intraclass correlation coefficients (ICCs) for inter- and intraobserver differences were calculated. Results The mean IFA in normal fetuses was 76.5° ± 6.3. Between the two measurement rounds of the same observer, the LOAs were -5.4 to 7.1 (obs. 1) and 7.4 to 8.4 (obs. 2). For IFA measurements by the same observer the ICC was 0.88 (obs. 1) and for measurements by two different observers the ICC was 0.74. The mean PFSR was 0.76 ± 0.40 and the intraobserver LOAs were -0.372 to 0.395 (obs. 1) and -0.555 to 0.667 (obs. 2). For PFSR measurements by the same observer the ICC was 0.89 (obs. 1) and for measurements by two different observers the ICC was 0.65. Among aneuploid fetuses, IFA was below the normal range in one third of the cases with trisomy 18. PFSR was below the 95% prediction limit in 16.2% of fetuses with trisomy 21% and 17.9% of fetuses with trisomy 18. Conclusion IFA can be reliably measured in 2D ultrasound images in the first trimester of pregnancy with a high interobserver agreement and may provide information about retrognathia associated with various syndromes and aneuploidies at early stages of pregnancy.

First trimester uterine artery pulsatility index levels in euploid and aneuploid pregnancies.

OBJECTIVE: To examine whether the uterine artery PI is different in aneuploid and euploid pregnancies. METHODS: Retrospective case-matched study at the department of prenatal medicine at the University of Tuebingen, Germany. The study involved patients with complete data on first trimester screening for trisomies and preeclampsia except PlGF. For each case with trisomy 21 we randomly selected 50 cases with a euploid fetus where complete data on screening for aneuploidy and preeclampsia were also available. The uterine artery pulsatility index and the corresponding MoM values of euploid and the aneuploid population were compared with a Man-Whitney U test. RESULTS: The dataset consisted of 4591 singleton pregnancies. The karyotype was normal in 4500 cases and was abnormal in the remaining 91 pregnancies. There were 50 pregnancies with trisomy 21, 31 with trisomy 18 and 13, and 10 with triploidy. In the group with euploid fetuses, median uterine artery PI was 1.55 (0.99 MoM). In the group with trisomy 21, the median PI (1.42) and MoM (0.89) levels were both significantly lower than in the euploid (p < 0.001). However, the measurements in the trisomy 18 and 13 [1.61 (0.93 MoM)] and in the triploidy [1.99 (1.13 MoM)] groups were not significantly different from those in the euploid group (p = 0.468 and p = 0.632, respectively). CONCLUSION: In conclusion, uterine artery PI levels in the first trimester are slightly lower in pregnancies with trisomy 21. This knowledge may prove to be useful in cases where a low PAPP-A level is seen on the first trimester maternal serum biochemical evaluation to differentiate whether the more likely cause for this finding is placental dysfunction or aneuploidy, specifically trisomy 21.

Chromosomal Microarray Analysis Results From Pregnancies With Various Ultrasonographic Anomalies.

OBJECTIVE: To examine chromosomal microarray analysis results in pregnancies with various ultrasonographic anomalies and to characterize the copy number variants in diverse fetal phenotypes. METHODS: We retrospectively examined chromosomal microarray analyses of amniocenteses performed nationwide as a result of fetal ultrasonographic anomalies (structural defects, fetal growth restriction, and polyhydramnios) between January 2013 and September 2017. The rate of abnormal chromosomal microarray findings was compared between the different phenotypes and with a previously described control population of 15,225 pregnancies with normal ultrasonographic findings. RESULTS: Clinically significant chromosomal microarray aberrations were detected in 272 of 5,750 pregnancies (4.7%): 115 (2%) karyotype-detectable and 157 (2.7%) submicroscopic. Most commonly detected copy number variants were 22q11.21 deletions (0.4%) followed by 22q11.21 gain of copy number (0.2%). Specific copy number variants detected among pregnancies with abnormal ultrasonographic findings were up to 20-fold more prevalent compared with low-risk pregnancies. Some variants were associated with specific phenotypes (eg, 22q11.21 microdeletions with cardiovascular and 17q12 microdeletions with genitourinary defects). CONCLUSION: The rate of abnormal amniotic chromosomal microarray analysis results is twice that of karyotypic abnormalities in pregnancies with various abnormal ultrasonographic findings.

Application of Neural Networks for classification of Patau, Edwards, Down, Turner and Klinefelter Syndrome based on first trimester maternal serum screening data, ultrasonographic findings and patient demographics.

BACKGROUND: The usage of Artificial Neural Networks (ANNs) for genome-enabled classifications and establishing genome-phenotype correlations have been investigated more extensively over the past few years. The reason for this is that ANNs are good approximates of complex functions, so classification can be performed without the need for explicitly defined input-output model. This engineering tool can be applied for optimization of existing methods for disease/syndrome classification. Cytogenetic and molecular analyses are the most frequent tests used in prenatal diagnostic for the early detection of Turner, Klinefelter, Patau, Edwards and Down syndrome. These procedures can be lengthy, repetitive; and often employ invasive techniques so a robust automated method for classifying and reporting prenatal diagnostics would greatly help the clinicians with their routine work. METHODS: The database consisted of data collected from 2500 pregnant woman that came to the Institute of Gynecology, Infertility and Perinatology "Mehmedbasic" for routine antenatal care between January 2000 and December 2016. During first trimester all women were subject to screening test where values of maternal serum pregnancy-associated plasma protein A (PAPP-A) and free beta human chorionic gonadotropin (ß-hCG) were measured. Also, fetal nuchal translucency thickness and the presence or absence of the nasal bone was observed using ultrasound. RESULTS: The architectures of linear feedforward and feedback neural networks were investigated for various training data distributions and number of neurons in hidden layer. Feedback neural network architecture out performed feedforward neural network architecture in predictive ability for all five aneuploidy prenatal syndrome classes. Feedforward neural network with 15 neurons in hidden layer achieved classification sensitivity of 92.00%. Classification sensitivity of feedback (Elman's) neural network was 99.00%. Average accuracy of feedforward neural network was 89.6% and for feedback was 98.8%. CONCLUSION: The results presented in this paper prove that an expert diagnostic system based on neural networks can be efficiently used for classification of five aneuploidy syndromes, covered with this study, based on first trimester maternal serum screening data, ultrasonographic findings and patient demographics. Developed Expert System proved to be simple, robust, and powerful in properly classifying prenatal aneuploidy syndromes.

Neuroradiological findings of trisomy 13 in a rare long-term survivor.

Patau syndrome remains a difficult diagnosis for parents and a challenging conversation for clinicians due to the overall poor prognosis. Previous population-based reports have documented the sobering life expectancies of these patients, with few surviving to 1 year of age. Despite the high mortality rate in infants born with trisomy 13, there are several reports of survival into late childhood and early adulthood. While clinical outcomes have been well documented, there has been a paucity of literature describing postnatal imaging findings in long-term survivors. We present a case report of a 2-year-old girl with trisomy 13 who underwent brain magnetic resonance imaging examination at our institution to evaluate for possible structural abnormalities contributing to central sleep apnea. We describe the clinical and postnatal neuroimaging findings of this rare patient with trisomy 13. Understanding the spectrum of neuroradiological findings in long-term survivors with trisomy 13, in combination with other organ system abnormalities, could add important clinical information and help better predict patient outcomes and expectations among parents.

Monozygotic Twins Discordant for Trisomy 13: A Case of Trisomic Rescue Supporting the Continued Need for First-Trimester Ultrasound.

Monozygotic twins with discordant karyotypes for trisomy 13 are rare. We report a case of a spontaneously conceived pregnancy who presented with first-trimester ultrasound finding of umbilical cord cyst and increased nuchal translucency in Twin A and no abnormalities in Twin B. Amniocentesis revealed 47,XY,+13 karyotype in Twin A and 46,XY karyotype in Twin B. Selective fetal reduction was performed for Twin A. Twin B was delivered at 32 weeks gestation with normal phenotype. Peripheral blood karyotype revealed 15% mosaicism for trisomy 13 and skin fibroblast revealed 46,XY karyotype. The surviving twin will be monitored for potential complication of uniparental disomy 13 and mosaic trisomy 13. This case reinforces the need for early ultrasound and nuchal translucency measurements, especially in twin gestations.

Sphenofrontal distance in euploid and aneuploid fetuses.

OBJECTIVE: To examine the sphenofrontal distance (SFD) in a large series of aneuploid fetuses in the second and third trimesters and compare findings with those of a euploid population. METHODS: The database at our unit was searched to identify pregnancies with a diagnosis of trisomy 21, 18 or 13, triploidy or Turner syndrome after 15 weeks' gestation. Stored ultrasound images obtained between 19 and 22 weeks were reviewed. For the normal population, two euploid fetuses matched for gestational age were selected randomly for each aneuploid case. The SFD was measured from the anterior edge of the sphenoid bone to the lowest posterior edge of the frontal bone using on-screen calipers. The SFD measurement was parallel to the long axis of the maxilla. If the sphenoid bone did not extend superiorly enough for direct measurement of the SFD, a tangential line was drawn at the anterior wall of the sphenoid bone and extended cranially. In these cases, the distance between the extended line and the frontal bone was measured. One operator measured the SFD twice and was blinded to the results and karyotype. RESULTS: The study population consisted of 591 pregnancies: 394 euploid fetuses, 122 fetuses with trisomy 21, 45 with trisomy 18, 16 with trisomy 13, eight with Turner syndrome and six with triploidy. For both euploid and aneuploid groups, mean gestational age at examination was 22.8 (range: euploid, 15.0-40.7; aneuploid, 15.0-40.3) weeks. For euploid fetuses, mean SFD was 1.27 cm and measurements ranged from 0.53 cm to 2.56 cm. SFD was significantly dependent on gestational age (SFD = 0.138 + 0.005 × gestational age, P < 0.001, r = 0.802). Mean SFD was significantly smaller in each aneuploid group compared with the euploid population (trisomies 21, 18 and 13: all P < 0.001; triploidy: P = 0.026; Turner syndrome: P = 0.047). For 32 (26.2%), nine (20.0%) and six (37.5%) fetuses with trisomy 21, 18 and 13, respectively, SFD was < 5th percentile. Only one (12.5%) fetus with Turner syndrome and none with triploidy had SFD < 5th percentile. CONCLUSION: In aneuploid fetuses, the SFD is smaller than in their euploid counterparts. However, for a false-positive rate of 5%, the detection rate of trisomy 21 is only 26%. Therefore, using the method we have proposed, it is unlikely that this marker will play a major role in second- and third-trimester screening for aneuploidy. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.