Congenital lymphedema presenting with increased nuchal translucency at 13 weeks of gestation

Congenital lymphedema is an autosomal dominant condition characterized by chronic tissue swelling caused by deficient lymphatic drainage due to hypoplastic/aplastic lymphatic vessels and usually affecting the lower limbs. The locus of the gene has been identified in the long arm of chromosome 15. We report one case of congenital lymphedema presenting with increased nuchal translucency at 13 weeks of gestation. Copyright © 2002 John Wiley & Sons, Ltd.     

Congenital nephrotic syndrome presenting with increased nuchal translucency in the first trimester

Congenital nephrotic syndrome of the Finnish type (CNF) and diffuse mesangial sclerosis (DMS) are rare causes of renal failure in infants. We report two cases, one of each condition, presenting with increased nuchal translucency at the 11–14-week scan, and review the literature. Copyright © 2002 John Wiley & Sons, Ltd.     

Optimising the timing for nuchal translucency measurement

It appears from current evidence that the most effective screening strategy for Down syndrome will involve a combination of first trimester nuchal translucency and serum biochemistry, whether performed in the first or second trimester. The aim of this study was to determine the optimum gestation based upon menstrual dates at which to schedule nuchal translucency (NT) measurement for the evaluation of fetal Down syndrome risk. Five thousand eight hundred and thirty-five pregnancies had an ultrasound scan scheduled between 11 and 14 completed weeks of gestation based upon either the last menstrual period (n = 3199) or a prior ultrasound scan (n = 2636). For last menstrual period-based ultrasound scans, with advancing gestation the frequency of missed miscarriage significantly decreased (p = 0.009, chi squared test), as did the need to reschedule a further scan because the gestation of the scheduled scan was too early to measure NT (p < 0.0001, Chi-squared test). In contrast, with advancing gestation the rate of unsuccessful NT measurement because the crown–rump length (CRL) was greater than 84 mm significantly increased (p < 0.0001, Chi-squared test). Of the women who had had an earlier ultrasound, 42 (1.6%) had a missed miscarriage and 9 (0.3%) were over gestation at the time of the NT scan. These data suggest that when only the last menstrual period is known the optimum time to schedule a nuchal translucency measurement is at 12 to 13 weeks' gestation. Copyright © 2002 John Wiley & Sons, Ltd.     

Early amniocentesis and fetal nuchal translucency in women requesting karyotyping for advanced maternal age

Fetal nuchal translucency was measured at 11–14 weeks' gestation in 97 pregnancies referred for early amniocentesis for advanced maternal age. The nuchal translucency was abnormal in 11 fetuses and the fetal karyotype was abnormal in five of these 11 cases. The karyotype was normal in 86 cases with normal nuchal translucency. The culture failure and miscarriage rates associated with early amniocentesis were 3·3 per cent and 2·2 per cent respectively. Amniotic fluid leakage occurred in 6 per cent of cases. In women requesting fetal karyotyping for advanced maternal age without additional biochemical screening, fetal nuchal translucency should be measured at 11–14 weeks. If the nuchal thickness is ≥ 3 mm, a first-trimester diagnostic procedure is indicated; however, if it is <3 mm, amniocentesis should be delayed until 16 weeks' gestation.     

The effect of fetal gender on nuchal translucency at 10–14 weeks of gestation

Recent data have suggested that fetal nuchal translucency (NT) is affected by fetal gender. We investigated the size of this effect in 12 189 unselected pregnancies with known normal outcomes that had undergone NT measurements between 10 and 14 weeks of gestation. NT increased with gestation and was converted to multiples of the median (MoM) for the gestational day. The median NT MoM (95% CI) for female fetuses was 0.98 (0.97–0.99). This was significantly lower than that of the male fetuses (1.03; range1.02–1.04) (p<0.0005; Wilcoxon rank-sum test). The gender difference was not observed at 10 weeks but was observed from 11 weeks onwards. There is no obvious explanation for the above findings. Copyright © 2001 John Wiley & Sons, Ltd.     

Three- versus two-dimensional ultrasound for nuchal translucency thickness measurements: comparison of feasibility and levels of agreement

We have determined feasibility and levels of agreement for visualizing the nuchal translucency within a time limit with three-dimensional (3D) and two-dimensional (2D) transvaginal ultrasound. A total of 213 women of median gestational age 13 weeks (range 11–14 weeks) undergoing first-trimester nuchal translucency (NT) thickness measurements with 2D transabdominal ultrasound were included in the study. Additionally all women underwent 2D and 3D transvaginal NT examination within a time limit of 90 s. These two methods were compared with each other and with our standard method (2D transabdominal ultrasound) with respect to visualization of fetal nuchal fold and to the levels of agreement. The nuchal fold was visualized by 3D and 2D transvaginal ultrasound in 85.9% (95% CI: 80.5%, 90.3%) and 25.8% (95% CI: 20.1%, 32.2%), respectively (p<0.001). There was a statistically significant underestimation of the NT by 2D transabdominal as compared with 3D transvaginal ultrasound of 0.1 mm (p<0.001), and by 3D transvaginal as compared with 2D transvaginal ultrasound of even 0.1 mm (p<0.001). 3D transvaginal ultrasound of the nuchal fold has increased feasibility to 2D transvaginal ultrasound within a short examination time and with minimal, but significant, measurement differences. Copyright © 2001 John Wiley & Sons, Ltd.     

Combining nuchal translucency and serum markers in prenatal screening for Down syndrome in twin pregnancies

A method is described to combine the ultrasound marker nuchal translucency (NT) with serum markers so that they can be used together in prenatal screening for Down syndrome in twin pregnancies. For monochorionic twin pregnancies (taken as monozygous), the two fetus-specific NT measurements are averaged before risk is calculated and before the contribution of the serum markers is incorporated. For dichorionic twin pregnancies (taken as dizygous), the risk for each fetus based on the individual NT measurements is calculated, the two fetus-specific risks are added together, and then the contribution of the serum markers is incorporated. In this way, all the screening markers can be used in combination to produce a pregnancy-specific ‘pseudo-risk’, rather than a fetus-specific pseudo-risk. We refer to pseudo-risk because in the absence of sufficient data on the screening markers in affected twin pregnancies, a true risk estimate cannot be calculated. Tentative estimates are given of screening performance in twins using NT, the combined test (NT with first-trimester serum markers), and the integrated test (NT with first- and second-trimester serum markers), all interpreted with maternal age. Copyright © 2003 John Wiley & Sons, Ltd.