OBJECTIVE To determine the relationship between a priori risk for fetal trisomy and the fraction of fetal cell-free DNA (cfDNA) in maternal blood. METHODS A comparative analysis on fetal cfDNA amounts was performed in subjects stratified into a priori risk groups based on maternal age, prenatal screening results, or nuchal translucency measurement. RESULTS Across the highest and lowest deci...

Purpose. To compare the measurements of fetal nuchal fold (NF) thickness by two-dimensional (2D) and three-dimensional (3D) ultrasonography using the three-dimensional extended imaging (3DXI). Methods. A cross-sectional study was performed with 60 healthy pregnant women with a gestational age between 16 and 20 weeks and 6 days. The 2D-NF measurements were made as the distance from the outer sku...

Chromosome 13 is one of the acrocentric chromosomes of the human karyotype. Acrocentric chromosomes are the most variable chromosomes in the human karyotype and these variations appear to have no clinical consequences. To the best of our knowledge, this is the first reported case of a first trimester presentation of a 13 short arm satellite deletion with markedly increased nuchal translucency (...

Nuchal translucency (NT) measurement between 11 and 14 weeks' gestation is an undisputed marker for aneuploidies. When conventional karyotyping is normal, enlarged NT is a strong marker for adverse pregnancy outcome, associated with miscarriage, intrauterine death, congenital heart defects, and numerous other structural defects and genetic syndromes. The risk of adverse outcome is proportional ...

We have studied changes in first trimester fetal nuchal translucency (NT) and maternal serum free beta-hCG and PAPP-A with gravidity and parity in 3252 singleton pregnancies unaffected by chromosomal abnormality or major pregnancy complications. We have shown that gravidity and parity is associated with a small but progressive decrease in fetal NT and a small but progressive increase in free be...

OBJECTIVE To determine whether in screening for trisomy 21 by measurement of fetal nuchal translucency (NT) thickness in monochorionic twin pregnancies it is preferable to use the higher, smaller or average NT. METHODS We retrospectively examined 769 monochorionic twin pregnancies that had undergone NT screening. The selection criteria were that first, in each pregnancy both fetuses were aliv...

OBJECTIVE To estimate intersonographer and intrasonographer variance components of fetal nuchal translucency (NT) thickness measurement using the traditional manual approach and a new semi-automated system. METHODS A semi-automated method was developed for measurement of the NT. In this method, the operator places an adjustable box over the relevant area at the back of the fetal neck. The sys...

We have studied maternal serum free beta-hCG and PAPP-A, and fetal nuchal translucency (NT) in a series of 46 cases of fetal Turner's syndrome, 13 cases of other sex chromosomal anomalies and compared these with 947 control pregnancies in the first trimester. In cases of Turner's syndrome (45,X) the median fetal NT was significantly higher than in controls (4.76 MoM), the median PAPP-A was sign...

BACKGROUND First-trimester nuchal translucency (NT) and second-trimester triple test (TT) are common screening programmes for trisomy 21. The aim of this study was to compare disclosure and non-disclosure approaches of combining those tests. METHODS Likelihood ratios of both NT and TT tests, among 508 normal and 23 trisomy 21-affected pregnancies, were used for calculating population-adjusted...

OBJECTIVE To update the likelihood ratio for trisomy 21 in fetuses with absent nasal bone at the 11-14-week scan. METHODS Ultrasound examination of the fetal profile was carried out and the presence or absence of the nasal bone was noted immediately before karyotyping in 5918 fetuses at 11 to 13+6 weeks. Logistic regression analysis was used to examine the effect of maternal ethnic origin and...