Increased Nuchal Translucency Thickness Research Articles

Associations between genomic aberrations, increased nuchal translucency, and pregnancy outcomes: a comprehensive analysis of 2,272 singleton pregnancies in women under 35.

Regarding increased nuchal translucency (NT), the cutoff values used are heterogeneous in clinical practice, this study aims to assess the efficacy of prenatal detection for chromosomal abnormalities and pregnancy outcomes in fetuses with varying NT thicknesses, in order to provide data that supports informed prenatal diagnosis and genetic counseling for such cases. We included 2,272 pregnant women under 35 with singleton pregnancies who underwent invasive prenatal diagnosis between 2014 and 2022. The cohort comprised 2,010 fetuses with increased NT (≥2.5 mm) and 262 fetuses with normal NT but exhibiting a single soft marker. Prenatal diagnoses were supported by chromosomal microarray (CMA) and copy number variation sequencing (CNV-seq) analyses. The detection rates of numerical chromosomal abnormalities were 15.4% (309/2,010) and 17.3% (297/1,717) in the NT ≥2.5 and ≥ 3.0 groups, respectively. Pathogenic/likely pathogenic CNV incidence increased with NT thickness (χ2 = 8.60, p < 0.05), peaking at 8.7% (22/254) in the NT 4.5-5.4 mm group. Structural defects were found in 18.4% of fetuses with NT values between 2.5 mm and 2.9 mm. Chromosomal abnormality rates in the isolated increased NT groups of 2.5-2.9 mm and 3.0-3.4 mm were 6.7% (16/239) and 10.0% (47/470), respectively, with no statistical significance (χ2 = 2.14, p > 0.05). Fetuses with NT thickness between 2.5 and 2.9 mm combined with the presence of soft markers or non-lethal structural abnormalities exhibited a significantly higher chromosomal abnormality risk (19.0%) compared to fetuses with isolated increased NT ranging from 3.5 to 4.4 mm (13.0%). Pregnancy termination rates increased with NT thickness (χ2 = 435.18, p < 0.0001), ranging from 12.0% (30/249) in the NT 2.5-2.9 mm group to 87.0% (141/162) in the NT ≥ 6.5 mm group. CMA or CNV-seq exhibited good performance in identifying genomic aberrations in pregnancies with increased NT thickness. NT ranging from 2.5 mm to 2.9 mm elevated the risk of fetal chromosomal abnormalities, particularly when combined with other soft markers.

Adverse pregnancy outcome in fetuses with early increased nuchal translucency: prospective cohort study.

An increased nuchal translucency (NT) ≥3.5mm is a well-established marker for congenital anomalies and adverse pregnancy outcome between 11 and 14 weeks of gestation. Little is known about its performance as a screening tool before 11 weeks of gestation. We aimed to investigate in a prospective setting whether fetuses with an increased NT before 11 weeks of gestation are at risk for an adverse pregnancy outcome. This is a prospective cohort study including pregnant women with a viable fetus with a NT≥2.5mm and a crown-rump-length (CRL) <45mm. All women were referred to our fetal medicine unit (FMU) and scheduled for a follow-up scan where the NT was remeasured after one week when the CRL was >45mm. Two groups were evaluated: cases with a normalized NT(<3.5mm) and cases with a persistently increased NT (≥3.5mm). We monitored the cases until four weeks after delivery. The main outcome was a composite adverse outcome of aneuploidies, other genetic disorders, structural anomalies and pregnancy loss. We performed subgroup analyses of NT thickness at inclusion and normalized or persistently increased NT at follow-up. We included 109 cases of which 35.8% (39/109) had an adverse pregnancy outcome. Of these 64.1% (25/39) were aneuploidies which corresponds to 22.9% (25/109) aneuploidies in total. The subgroups of NT thickness at inclusion of 2.5-3.4, 3.5-4.4 and ≥4.5mm showed abnormal outcomes in 22.0% (9/41), 40.0% (18/45), 52.2% (12/23) respectively. In fetuses with a normalized NT and without ultrasound abnormalities at follow-up scan, the incidence of adverse outcome was 8.5% (5/59), of which 5.1% (3/59) were aneuploidies. Fetuses with an early increased NT thickness are at considerable risk of an adverse pregnancy outcome, even if the NT normalizes after 11 weeks. Not all congenital anomalies can be diagnosed with routine first-trimester screening such as non-invasive prenatal testing and/or a first-trimester anomaly scan. Therefore, expectant parents should always be referred to a FMU for detailed ultrasonography. Invasive prenatal testing should be offered if an increased nuchal translucency of ≥2.5mm is observed before 11 weeks of gestation. This article is protected by copyright. All rights reserved.

CLINICAL, ULTRASOUND AND CYTOGENETIC CHARACTERISTICS OF FETUSES WITH INCREASED NUCHAL TRANSLUCENCY THICKNESS IN THE FIRST TRIMESTER OF PREGNANCY

Background: Improving programs for early prenatal detection of congenital malformations remains a relevant scientific and practical problem. The prevalence of congenital anomalies in Ukraine is 23.7:1000 among live-born babies, and there is no significant decrease in it. The aim of this study was to compare clinical, ultrasound and cytogenetic data in swollen fetuses with increased nuchal translucency (NT) thicknesses from the group of pregnant women in the first trimester at high genetic risk to optimize the algorithm of prenatal diagnostics.&#x0D; Materials and Methods: Clinical examinations, ultrasound diagnostics, invasive methods of prenatal diagnostics (chorion biopsy, amniocentesis), genetic testing techniques, such as karyotyping and FISH, genetic counseling and statistical analysis were carried out. The results of complex examinations of 127 fetuses with an increased NT thickness from the group of pregnant women were analyzed. Fetuses were divided into two groups with an NT thickness of 2.5–3.5 mm (group 1) (38 cases) and with an NT above 3.5 mm (group 2)(89 cases).&#x0D; Results: Among pregnancies with fetuses with an increased NT thickness, there were 65.4% cases of adverse outcomes with chromosomal pathology (69.9%), congenital malformations of non-chromosomal etiology (25.3%) and pregnancy loss (4.8%). The frequency of chromosomal abnormalities in fetuses of group 1 was 55.3% and 41.6% in group 2. Congenital malformations of various systems and organs in fetuses, the most frequent of which were cardiac defects, were diagnosed. The ratio of congenital heart defects in the fetuses of groups 1 and 2 was 23.7% and 43.8%, respectively (p=0.03; OR=0.40).&#x0D; Conclusion: There is no significant difference between the frequency of chromosomal abnormalities in the fetuses of group 1 compared to group 2, which indicates a high informative value of an increased NT thickness, including the thickness of 2.5–3.5 mm in fetuses in the first trimester as a marker of chromosomal pathology. A significantly higher incidence of congenital malformations of non-chromosomal etiology was found in fetuses with venous duct pathology and NT thickness over 3.5 mm compared to fetuses with the same pathology and NT thickness of 2.5–3.5 mm. Proposed changes to the management algorithm for pregnant women with swollen fetuses include mandatory congenital heart defects screening in the first trimester.

Congenital Heart Diseases: Risk Factors and Ultrasound Diagnostic Potential at the First Screening

Introduction: Due to the high incidence of congenital heart diseases (CHD) it is important to identify risk factors for abnormal organogenesis. There is a crucial medical need to understand cardiogenesis and possible markers of abnormalities in fetuses.Objective: To determine risk factors for CHD in pregnant women and their partners and assess CHD markers on the first ultrasound screening.Materials and methods: We analyzed 221 medical records of pregnant women with prenatally diagnosed fetal CHD and divided the patients into 2 groups: group I (n = 177) with CHD compatible with postnatal development and group II (n = 44) with CHD incompatible with postanatal development. We evaluated physical findings and somatic and reproductive history in both groups. We retrospectively analyzed 2272 ultrasound scans and first screening markers: nuchal translucency (NT) thickness and ductus venosus pulsatility index (DVPI).Results: We identified possible risk factors for fetal CHD: body mass index, P = .000; age of menarche, P = .037; chronic tonsillitis, Р = .046; cervical erosion, Р = .045; vulvovaginal candidiasis, Р = .005; vaginitis, Р = .027; cervicitis, Р = .027; chronic hepatitis B and C viruses, Р = .005; respiratory tract infection with fever during the current pregnancy, Р = .012. We built 500 networks with the highest performance for a predictive model and found that the model’s predictors did not fully represent the risk factors for CHD. CHD with increased NT thickness (≥2.5 mm) was detected in 2.24% of cases. NT thickness and DVPI were 3.37 ± 0.92 mm and 1.098 ± 0.158, respectively. According to our correlation analysis, increased DVPI and NT thickness were associated with CHD (R = 0.510).Conclusions: It is not possible to identify risk factors for CHD in fetuses by medical history, reproductive history and physical status of pregnant women, and unhealthy habits of their sexual partners. Increased NT thickness and DVPI moderately correlate with CHD incidence.

Fetal left ventricular myocardial performance index measured at 11-14 weeks of gestation in fetuses with an increased nuchal translucency.

This study aimed to evaluate the effect of an increase in nuchal translucency (NT) thickness on the myocardial performance index (MPI) in fetuses without cardiac anomaly in the first trimester and to determine whether a difference in MPI between those with and without trisomy 21 in these fetuses could be determined. The study group consisted of 53 pregnancies complicated with increased NT thickness without any associated structural anomalies. Forty-six gestational age-matched pregnant women whose fetuses had normal NT thickness were enrolled as the control group. In the increased NT thickness group, the mean isovolumetric relaxation time (IRT) value (0.050 ± 0.011 s) was significantly higher and the mean ejection time (ET) value (0.149 ± 0.010 s) was significantly lower than those values in the normal NT thickness group (0.045 ± 0.005 and 0.155 ± 0.009 s, p=0.023 and p=0.009, respectively). We found a significantly higher mean left MPI value in the increased NT thickness group (0.574 ± 0.153) versus the normal NT thickness group (0.487 ± 0.107, p < 0.001). Within the increased NT thickness group, the mean left MPI value was similar in the fetuses with normal karyotype and those with trisomy 21 (p=0.419). We demonstrated a significantly greater mean MPI value in the increased NT thickness group than in the normal NT thickness group. Within the increased NT thickness group, no differences in the left MPI value in the fetuses with normal karyotype and the fetuses with trisomy 21 were found.

A prospective cohort study on association of first-trimester serum biomarkers and risk of isolated foetal congenital heart defects

Background This study aims to assess the association between first-trimester biomarkers in foetuses with a non-chromosomal congenital heart defect (CHD) and compares it to the matched healthy foetuses. Method Nuchal Translucency (NT), Pregnancy-Associated Plasma Protein-A (PAPP-A) and free beta-human Chorionic Gonadotropin (β-hCG) were evaluated in 56 isolated foetal heart defects and 224 controls. The CHDs were further divided into Critical CHD (C-CHD) and Non-critical CHD (N-CHD) groups. Results The multiple of the median (MoM) values for PAPP-A were significantly lower (0.87 MoM vs. 0.92 MoM; p = 0.008) in the total CHD group than in controls. The median of foetal NT values was significantly higher in the total CHDs than in controls (1.16 MoM vs. 1.03 MoM; p < 0.001), especially for C-CHDs (1.28 MoM; P < 0.001). There were no significant differences in terms of PAPP-A (p = 0.779) and foetal NT values (p = 0.760) between the N-CHDs and control groups. There were no significant differences within the groups based on free β-hCG, except for a lower β-hCG in C-CHD group than in the control group (0.95 MoM vs. 1.11 MoM; p = 0.022). Conclusion Lower PAPP-A levels and increased NT thickness were associated with an increased risk of CHDs, especially the critical type of CHDs. Clinical significance Maternal serum PAPP-A, measured in the first trimester, is significantly lower in CHD. Foetal NT is significantly thicker in foetuses with CHD, especially those with critical CHD. Maternal serum β-hCG was only decreased among critical CHD group.

Outcome of the fetuses with severely increased nuchal translucency thickness in the first trimester.

To study the outcome of pregnancies with severely increased nuchal translucency (NT) thickness at the 11-13-week scan. This study included 162 singleton pregnancies whose fetuses had increased NT thickness ≥ 5.5 mm between September 2013 and August 2018. The cases were divided into two groups: NT ≥ 6.5 mm (n = 112) (group A); and 6.5 mm > NT ≥ 5.5 mm (n = 50) (group B). Fetal (amniotic fluid) or placental (chorionic villous) chromosome analyses were conducted. Subsequent ultrasound findings, pregnancy outcome and structural defects in the neonates were recorded and analyzed. Abnormal karyotype was found in 71% (60/84) (group A) and 57% (21/37) (group B) of the cases respectively. In group A, 15 cases out of 24 with normal karyotype were born. Among these 15 cases, one case died soon after birth and 5 cases had associated abnormalities. In group B, 13 cases out of 18 with normal karyotype or negative noninvasive prenatal testing results and 1 case out of 2 cases with 47,XXY were born. All of them survived with no major anomaly. Incidence of chromosomal aberrations was high in the cases with severely increased NT thickness. But favorable outcome could be expected if the fetus had no chromosomal abnormality and no abnormal findings were found in second trimester ultrasound scan especially in a fetus with increased NT < 6.5 mm.

Pregnancy outcome in foetuses with increased nuchal translucency – 10-years’ experience in a prenatal medical practice

This retrospective study describes pregnancy outcome for foetuses with increased nuchal translucency (NT) in relation to the degree of increase in a local specialised medical practice. Data from 7352 first trimester pregnancies examined by a single observer between 10/07 and 07/17 were screened. Three hundred and ninety-three foetuses (5.3%) that had an increased NT ≥ 95th percentile and available pregnancy outcome were identified. For this population, the frequencies of chromosomal abnormality, foetal malformation, intrauterine death (IUD) and termination of pregnancy (TOP) were determined in relation to the degree of NT thickness. Favourable pregnancy outcome decreased from 77.8% (lowest NT group, 95th percentile–3.5 mm) to 5% (highest NT ≥ 6.5 mm), whereas chromosomal abnormalities rose from 18.1% to 70%. An abnormal karyotype occurred in 39.2% of foetuses with increased NT. In euploid foetuses, cardiac defects were the most common structural abnormalities. The data largely matches with earlier studies conducted in large hospital-based settings. However, a rather high proportion of foetuses with abnormal karyotype was observed.IMPACT STATEMENTWhat is already known on this subject? Increased NT is associated with chromosomal abnormalities as well as an adverse perinatal outcome also in foetuses with a normal karyotype. The prevalence of an adverse outcome increases with NT thickness. These studies were conducted more than 10 years ago mainly in academic settings.What do the results of this study add? This study describes pregnancy outcome of a population of foetuses with increased NT that were examined in a medical practice by a single observer over a period of 10 years with state of the art ultrasound equipment. We observed a relatively large proportion of foetuses with abnormal karyotype. In euploid foetuses, increased NT was associated with a wide range of foetal malformations and genetic syndromes.What are the implications of these findings for clinical practice and/or further research? Even mildly increased NT thickness is associated with an adverse pregnancy outcome, underlining the importance of thorough ultrasound examinations. Specialised prenatal medical practices can provide state-of the art technology and provide improve parental counselling.

Diagnostic value of ultrasound scan at 16 to 18 gestational weeks in euploid fetuses with increased nuchal translucency

Objective To investigate the diagnostic value of ultrasound scan at 16 to 18 gestational weeks in euploid fetuses with increased nuchal translucency (NT). Methods From January 2015 to June 2017, 214 fetuses diagnosed with increased NT thickness (NT ≥3.0 mm) during early pregnancy in Guangzhou Panyu Central Hospital were enrolled. Fetal chromosome karyotype analysis was carried out prenatally. Those cases with normal karyotype underwent ultrasound scan at 16-18 and 20-24 gestational weeks and their outcomes were followed up via telephone. Descriptive statistics was used for statistical analysis. Results There were 198 out of the 214 cases undergoing chromosome karyotype analysis and among them, 78 (39%) pregnancies were terminated due to chromosomal abnormalities. Out of the 107 cases with normal karyotype and successful follow-ups, 35%(37/107) had structural malformations. There were 19, 11 and 6 cases of fetal structural malformations diagnosed at 11-13+6, 16-18 and 20-24 weeks of gestational age, respectively, and the rest one was at 28 weeks. Structural deformities detected at 16-18 weeks included cleft lip and palate (n=2), cardiac malformations (n=2), spinal deformities (n=2), body deformities (n=2), diaphragmatic hernia (n=1), encephalocele (n=1) and left multicystic dysplastic kidney (n=1). About 91% (70/77) of the fetuses with normal karyotype but without abnormal ultrasound findings at 16-18 weeks were free of structural malformations and achieved good pregnant outcomes. Conclusions Ultrasound screening at 16 to 18 weeks of pregnancy can be used to detect multiple structural malformations in fetuses with increased NT and normal karyotype, which may contribute to early detection of fetal structural malformations and help gravidas and their families make timely decisions. Key words: Ultrasonography, prenatal; Nuchal translucency measurement; Pregnancy outcome

First-trimester ultrasound screening for prenatal diagnosis of fetal congenital heart disease

Objective To investigate the value of standardized ultrasound screening in diagnosis of fetal congenital heart disease (CHD) during the first trimester. Methods This study retrospectively analyzed the clinical data of 8 383 fetuses who received ultrasound screening during the first trimester in the Dongguan Maternal and Child Health Hospital from September 2015 to December 2016. Standardized ultrasound was performed to observe fetal heart position, apical direction, apical four-chamber view, three vessels and trachea view and the thickness of nuchal translucency (NT). Fetuses with thickened NT or fetal CHD observed during the first and second trimester were followed up. Pregnancy outcomes and the growth of newborns within one year after birth were recorded and analyzed. Pathological results after the termination of pregnancy were compared with the results of routine karyotyping and chromosome microarray analysis (CMA). Results (1) A total of 27 cases of fetal CHD were identified during the first trimester giving a detection rate of 0.32% (27/8 383). These included ten (37.0%) of single atrium and/or single ventricle, seven (25.9%) of endocardial cushion defect (including two complicated by persistent arterial trunk), three (11.1%) of hypoplastic right heart syndrome, three (11.1%) of interventricular septal defect, two (7.4%) of hypoplastic left heart syndrome, one (3.7%) of mirror-image dextrocardia and one (3.7%) of right atrial enlargement and severe tricuspid regurgitation. Nineteen out of the 27 cases had NT thickening (NT≥3.0 mm) and 17 of them had a cystic hygroma (NT≥6.0 mm). Among the 27 cases, 22 were terminated in the first trimester which autopsy results were consistent with ultrasound and the other five were rescreened during the second trimester. Thirteen out of the 27 cases received chorionic villus sampling, and seven of them were found to have chromosomal abnormalities by karyotyping and CMA, among whom one was microdeletion of 22q11. (2) Twenty-one cases of CHD were detected in the second-trimester ultrasound screening, including five initially identified in the first trimester. These cases included four (19.0%) of complex cardiac malformations (with three or more malformations), four (19.0%) of interventricular septal defect, three (14.3%) of dextroaortic arch, left subclavian artery vagus and 'U' shaped vascular ring, three (14.3%) of hypoplastic right heart syndrome (including one complicated by coronary artery-right ventricular fistula and one by interventricular septal defect), two (9.5%) of transposition of the great arteries, two (9.5%) of tetralogy of Fallot, one (4.8%) of hypoplastic left heart syndrome, one (4.8%) of Taussig-Bing anomaly and one (4.8%) of coarctation of the aorta. Among the 16 cases first identified in the second trimester, eight had NT thickening, including one with cystic hygroma. Among the 21 cases, two were lost to follow-up after being transferred to another hospital; four with negative results in karyotype analysis and CMA were delivered vaginally at term (37-40 gestational weeks) with 1-min Apgar scores of ten points and postpartum ultrasound of the baby was consistent with the second-trimester ultrasound screening; 15 were terminated and the autopsy confirmed those findings in the second-trimester ultrasound screening. Eleven out of the 21 cases received amniocentesis and five of them were found to be abnormal according to karyotype analysis and CMA, including one of microdeletion of 22q11. Conclusions Standardized first-trimester ultrasound screening is important and of great clinical value in the diagnosis of fetal CHD. Increased NT thickness could be a key indicator of fetal CHD and chromosomal abnormalities in early pregnancy. CMA may facilitate detecting the abnormality of genetic material in fetuses with normal chromosome karyotype. Key words: Heart defects, congenital; Ultrasonography, prenatal; Pregnancy trimester, first; Microarray analysis

Analysis for the pregnancy outcome of cystic hygroma fetuses and correlation with increased nuchal translucency in first trimester

Objective: To analyze prognosis-related risk factors of first trimester cystic hygroma (CH) fetuses in which nuchal translucency (NT) was found to be thickened. Methods: Tolly 216 singleton pregnancies in which fetal NT≥3.0 mm at the 11~13+6 weeks scan accepted invasive prenatal diagnosis in Beijing Gynecology and Obstetrics Hospital, Capital Medical University, from January 2014 to December 2015 were collected. A total of 164 (75.9%, 164/216) single fetuses with complete data were included, they were classified into two groups, namely 'CH' and 'increased NT' which without CH. And 40 pregnancies (24.4%, 40/164) presented with CH group, 124 pregnancies (75.6%, 124/164) were with increased NT group. The chromosome karyotype abnormality, major organ structure malformation and adverse outcome were compared between the two groups. Logistic regression analysis was used to investigate the effect of increased NT thickness, the presence of septa in CH on abnormal karyotype, major congenital anomaly and adverse outcome. Results: (1) The incidence of fetal abnormal karyotype [55.0% (22/40) vs 29.0% (36/124) ], major organ anomalies [45.0% (18/40) vs 25.8% (32/124) ], and adverse outcome [92.5% (37/40) vs 50.8% (63/124) ] were significantly different (all P<0.05) between the CH group and the increased NT group. (2) NT measurement was significantly higher in the CH group than that in the increased NT group (8.32 vs 5.06 mm, P<0.01) . (3) Logistic analysis revealed that NT thickness was the significant risk factor in the prediction of adverse outcome for CH fetuses in first trimester. The risks of chromosomal defect, major congenital anomaly and adverse outcome increased 1.171, 1.192 and 1.913-fold (all P<0.05) with 1.0 mm increased NT thickness, while the presence of septa in CH didn't increase the risks of above (all P>0.05) . Conclusions: The perinatal outcome of CH is poor. The poor outcome of CH is closely attributed to thickened NT, and the presence of septa in CH does not increase the risk of adverse outcome for CH fetuses.

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English

Prenatal detection of congenital heart disease in a low risk population undergoing first and second trimester screening.

The prenatal detection rate of congenital heart disease (CHD) is low compared with other fetal malformations. Our aim was to evaluate the prenatal detection of CHD in Eastern Denmark. Fetuses and infants diagnosed with CHD in the period 01.01.2008-31.12.2010 were assessed regarding prenatal detection rate and accuracy, as well as correlation with nuchal translucency (NT) thickness. Out of 86 121 infants, 831 were born with CHD (0.96%). The prenatal detection rate of 'all CHD' was 21.3%, of 'Major CHD' 47.4%. Full agreement between prenatal and postnatal/autopsy findings was found in 96% of prenatally detected diagnoses. An NT thickness >95(th) percentile was found in 15.0% fetuses with 'Major CHD'. Of 'Major CHDs' detected prenatally, 77% were picked up at the time of the malformation scan at weeks 18-21. Nearly half of 'Major CHDs' were detected prenatally. The prenatal cardiac diagnoses showed a high degree of accuracy. Increased NT thickness as a screening tool for CHD performed moderately but is an important high risk group for specialist examination. A minority of the prenatally detected CHDs was identified because of extra scans performed in high risk pregnancies. © 2014 John Wiley & Sons, Ltd.

Normal reference range of fetal nuchal translucency thickness in pregnant women in the first trimester, one center study.

Background:Considering that establishment of reference value of nuchal translucency (NT)-related to the crown rump length (CRL) during the first trimester will be helpful for determining an appropriate cutoff level for screening of increased NT thickness-related abnormalities, we determined the NT thickness and investigated its relation with different chromosomal and nonchromosomal abnormalities among a large sample size of pregnant Iranian women.Materials and Methods:In this analytic cross-sectional study, pregnant women who were in their first trimester were enrolled at their antenatal visit. Using an abdominal ultrasonography, the fetal NT thickness of the studied population was measured. Those with increased NT thickness were determined. The reference value of NT thickness (5th, 25th, 50th, 75th, and 95th percentiles) within each 5-mm range of CRL and during the 11th, 12th, and 13th gestational weeks were determined. The presences of the different chromosomal and nonchromosomal abnormalities were compared in women with different percentiles of NT thickness who underwent amniocentesis and those who did not.Results:1,614 pregnant women were evaluated. The mean NT thickness was 1.30 ± 0.54 mm. Increased NT thickness >2 mm and >95th percentile according to their gestational age (GA) was detected in 89 (5.5%) and 58 (3.6%) pregnant women. The reference 95th percentile value range for NT was 1.8-2.35 and increased NT thickness according to our obtained values was associated significantly with chromosomal abnormalities.Conclusion:The obtained reference range in our studied population was different from that reported for other ethnic groups and it is suggested that using this values are more favorable for screening of chromosomal abnormalities during the first trimester of pregnancy than the recommended single cutoff value.

Increased nuchal translucency and short femur length as possible early signs of osteogenesis imperfecta type III

this paper reports an association between an increased Nuchal Translucency (NT) and Osteogenesis Imperfecta (OI), a type of skeletal dysplasia. Measurement of fetal NT at 10-14 weeks of gestation is a sensitive and effective screening method for chromosomal abnormalities. a 35-year- old Caucasian woman in her fourth pregnancy was referred to our clinic for an ultrasound scan at 12 weeks of gestation, that confirmed increased Nuchal Translucency. Chorionic villi sampling was performed, showing a normal karyotype. The patient was evaluated by a team of experienced ultra sonographers for pregnancy follow-up at our Department, that is a tertiary center. in our case the ultrasound scan at 12 week of gestation revealed only an increased NT (3 mm). Cytogenetic analysis on chorionic villi demonstrated a normal male karyotype. US follow-up, performed every 3-4 weeks, confirmed normal anthropometric parameters except for shortening of both femurs, but at 23 weeks an incorrect attitude of the feet was revealed. A clinical and radiographic diagnosis of OI type III was made only at birth, and through follow-up continuing to date. NT screening was successful for chromosomal abnormalities at 11-14 weeks of gestation. An increased NT thickness is also associated with numerous fetal anomalies and genetic syndromes in a chromosomally normal fetus. In our case there were no sonographic signs of imperfect osteogenesis in the first trimester, although there was an increased NT with a normal karyotype. currently, in literature, there are not other cases of OI type III associated with an increased NT. Our report is the first to suggest an association between an increased nuchal translucency, short femur length and osteogenesis imperfecta type III.

Partial monosomy 13q (13q21.32→qter) and partial trisomy 8p (8p12→pter) presenting with anencephaly and increased nuchal translucency: array comparative genomic hybridization characterization

Objective To present array comparative genomic hybridization (aCGH) characterization of partial monosomy 13q (13q21.32→qter) and partial trisomy 8p (8p12→pter) presenting with anencephaly and increased nuchal translucency (NT). Case Report A 34-year-old primigravid woman was referred to the hospital at 12 weeks of gestation for termination of the pregnancy because of major structural abnormalities of the fetus. Prenatal ultrasound revealed a malformed fetus with anencephaly and an increased NT thickness of 5 mm at 12 weeks of gestation. Cytogenetic analysis of the fetus revealed a derivative chromosome 13. The mother was subsequently found to carry a balanced reciprocal translocation between 8p12 and 13q21. Bacterial artificial chromosome-based aCGH using fetal DNA demonstrated partial trisomy 8p and partial monosomy 13q [arr cgh 8p23.3p12 (RP11-1150M5→RP11-1145H12)×3, 13q21.32q34 (RP11-326B4→RP11-450H16)×1]. Oligonucleotide-based aCGH showed a 36.7-Mb duplication of distal 8p and a 48.4-Mb deletion of distal 13q. The fetal karyotype was 46,XY,der(13) t(8;13)(p12;q21.32)mat. The maternal karyotype was 46,XX,t(8;13)(p12;q21.32). Conclusion The 13q deletion syndrome can be associated with neural tube defects and increased NT in the first trimester. Prenatal sonographic detection of neural tube defects should alert chromosomal abnormalities and prompt cytogenetic investigation, which may lead to the identification of an unexpected parental translocation involving chromosomal segments associated with neural tube development.

P17.12: Nuchal translucency for detection of chromosomal abnormalities: a single center experience of 10 years in Brazil

To study the value of nuchal translucency (NT) measurement in the screening for chromosomal abnormalities at 11–14 weeks of gestation. A total of 5077 fetuses were studied consecutively at Vitoria MedifetUS, Vitoria, Brazil. In 370 cases a cytogenetic study was performed on material obtained from a biopsy of the chorionic villus, and in 4707 cases the result was based on the postnatal phenotype. In addition to the routine ultrasonographic examination, all fetuses were submitted to measurement of the NT thickness. For statistical analysis Student's t test and ANOVA were used. Sensitivity, specificity, positive and negative predictive values, false-positive rate and likelihood ratio were calculated. Seventy-nine cases of chromosomal abnormalities occurred. Of these abnormal cases, NT measurement was above the 95th percentile in 60 (sensitivity of 75.9%) and specificity was 98.0%, positive and negative predictive values were 38.0% and 99.6%, respectively, false-positive rate was 2.0% and likelihood ratio was 38.7. Our results suggest that the presence of chromosomal abnormalities may be strongly suspected when there is an increased NT thickness. Screening for aneuploidy in Brazil presents comparable results to those in other countries. It is a method of clinical applicability in any part of the world.

Nuchal translucency and nasal bone in first‐trimester ultrasound screening for aneuploidy in multiple pregnancies

To review our experience with first-trimester screening of chromosomal abnormalities in multiple pregnancies using nuchal translucency (NT) thickness measurement and nasal bone assessment. Cases of multiple pregnancy presenting for first-trimester ultrasound evaluation and with viable fetuses measuring between 45 and 84 mm were recruited for this study. Crown-rump length, NT thickness, the presence or absence of the nasal bone and chorionicity were determined and the information prospectively collected in a dedicated database. There were 206 twin pregnancies, eight sets of triplets, and one set of quadruplets, totalling 440 screened fetuses. Information on perinatal outcome was available in all cases. The NT thickness was measured in all cases and was found to be greater than the 95(th) percentile in six (8.6%) of the 70 monochorionic fetuses and in 10 (2.7%) of the 370 dichorionic fetuses (P < 0.05, Fisher's exact test). The nasal bone was successfully assessed in 421 of the 440 (95.7%) fetuses and found to be absent in only four cases, three of which were found to have aneuploidy. Chromosomal abnormalities were diagnosed in six fetuses from one monochorionic and four dichorionic twin pregnancies. Five of the six affected cases were associated with increased NT thickness (sensitivity 83.3%), whereas the nasal bone was absent in only three of the aneuploid fetuses (sensitivity 50%). First-trimester ultrasound screening for chromosomal abnormalities using NT thickness in multiple pregnancies is highly sensitive. However, nasal bone assessment is not only limited in sensitivity but also more challenging in multiple than in singleton pregnancies owing to difficulties in obtaining adequate views of the fetal face.

Nuchal Translucency Thickness in Monochorionic Multiple Pregnancies

The purpose of this study was to investigate the value of first-trimester nuchal translucency (NT) thickness in predicting the pregnancy outcome in monochorionic multiple pregnancies. Thirty monochorionic multiple pregnancies were evaluated for NT thickness at a median gestational age of 12 weeks (range, 11-14 weeks). Information on pregnancy outcome was obtained from all cases. A poor pregnancy outcome was defined as fetal death or miscarriage before 24 weeks, development of twin-twin transfusion syndrome (TTTS), or preterm delivery before 32 weeks. The NT thickness was above the 95th percentile for gestational age in at least 1 fetus in 5 (17%) pregnancies, and a poor pregnancy outcome was recorded in 14 (47%) pregnancies. The overall sensitivity was 36% (5/14); specificity, 100% (16/16); positive predictive value, 100% (5/5); and negative predictive value, 64% (16/25). In pregnancies with increased compared with normal NT thickness, no significant correlation was found with the subsequent development of TTTS (1/5 [20%] versus 5/25 [20%]) and miscarriage or fetal death before 24 weeks (1/5 [20%] versus 3/25 [12%]). However, among the 20 pregnancies not complicated by TTTS or loss before 24 weeks, there was a significantly increased rate of delivery before 32 weeks in the former group (3/4 [75%] versus 1/16 [6.3%]; P = .01). In monochorionic multiple pregnancies, an increased NT thickness measurement had a high specificity and positive predictive value for adverse perinatal outcomes. However, the sensitivity and negative predictive value were low, with a normal NT thickness measurement poorly predicting development of complications; therefore, close sonographic follow-up should be carried out in all cases, irrespective of NT thickness.

Relationship Between Nuchal Translucency Thickness and Prevalence of Major Cardiac Defects in Fetuses With Normal Karyotype

Measuring the thickness of the fetal nuchal translucency (NT) at 11 to 13 + 6 weeks is an effective way to screen for chromosomal defects. Increased NT has also been associated with major cardiac defects as well as numerous fetal malformations and genetic syndromes. In this study, the prevalence of major cardiac defects was determined by fetal echocardiography in 6921 fetuses with a normalor presumably normal-karyotype. The study was done at a median gestational age of 20 weeks. The most common indications were increased NT thickness on the 11 to 13 + 6 scan, a perceived need to estimate the risk of chromosomal abnormality, and a history or family history of fetal defects. Most often, the echo study was done transabdominally. Either chorionic villus sampling or amniocentesis demonstrated a normal fetal karyotype, or a phenotypically normal infant was born alive. Cases with other than cardiac fetal abnormalities were excluded. Major cardiac defects were found in 132 fetuses, a prevalence of 19.1 per 1000. The prevalence increased with fetal NT thickness. It was 4.9 per 1000 when NT thickness was below the median; 8.7 per 1000 with an NT thickness between the median and less than the 95th percentile; 18.2 per 1000 for an NT thickness between the 95th and 99th centiles; and then exponentially to 35.2, 64.4, and 126.7 mm, respectfully, for NT measurements of 3.5-4.4 mm, 4.5-5.4 mm, and 5.5 mm or greater. There was no apparent difference in the distribution of NT thickness values for different types of cardiac defects. The authors believe that combining a first-trimester NT thickness measurement with a second-trimester four-chamber echocardiographic view will promote the antenatal detection of major cardiac defects in fetuses with a normal karyotype.