Multi‐centre first‐trimester screening for Down syndrome in the Netherlands in routine clinical practice

Abstract

Objectives This is the first report on the results of a first‐trimester combined‐test screening programme in the Netherlands in a multi‐centre routine clinical setting. Methods Between July 2002 and May 2004, blood samples were taken from subjects in 44 centres in the Netherlands and sent to our laboratory to assay for maternal serum concentrations of fβ‐hCG and PAPP‐A. Fetal nuchal translucency (NT) was measured in the participating centres at a gestational age (GA) of 10–14 weeks. Results of those pregnancies for which a combined biochemical and NT risk was calculated were included in the epidemiological analysis of this study. Results A total of 4033 singleton pregnancies were included in the analysis. The median maternal age of the analysed group was 36.5 years. The distribution of GA was biphasic, with median GA of 10.3 and 12.1 weeks, respectively. The detection rate using the combined ultrasound and serum screening at a cut‐off level of 1 in 250 was 71% (15/21), with a screen‐positive rate of 4.7%. Conclusion The results of this study show that the first‐trimester combined test is suitable as a prenatal screening test in a multi‐centre routine clinical setting in the Netherlands. Strict performance evaluation should identify weaknesses in the organisation that impair the performance of the test. Here, the performance of NT was especially identified as a candidate for improvement. Copyright © 2006 John Wiley & Sons, Ltd.

Quality of nuchal translucency measurements in The Netherlands: a quantitative analysis

“…For Dutch operators, the latter curve seemed to give a more accurate estimate of expected medians. Over the period July 2002 to May 2004 a mean median NT‐MoM of 0.83, based on the reference curve of Nicolaides et al , was described8. In the current study, the median NT‐MoM increased over time (Figure 2) and was 0.96 at the end of 2006.…”

“…Two types of quality assurance can be distinguished, both of which have been applied to the measurement of NT7–9. With qualitative assurance, aspects which contribute to adequate NT measurement, for example a correct sectional plane view of the fetus or caliper placement, are evaluated through the submission of ultrasound prints by the operator to an examining body; based on scores given by experts the quality of NT measurements can be determined10.…”

Quality assessment of routine nuchal translucency measurements: a North American laboratory perspective

“…This setting differs from most other reports on this topic, in that the NT measurements are being performed as part of routine practice and not as part of a research protocol. 5,6,16,17 Given the widely varying characteristics of our participating laboratories, the findings are likely to be representative of current practice in North America. Overall, 39% of the screened women had NT measured by a sonographer who submitted too few samples to that laboratory for adequate and timely quality assurance monitoring.…”

Comparison of risk calculation approaches in a screening programme for Down syndrome

“…For this retrospective dataset information on the pregnancy outcomes (e.g., child ' s birth date, birth weight and chromosomal abnormalities) was available (collected through self-reporting of the pregnant women, with a 70 % recall rate and considered to be an unbiased representation of the study population -see [9] -with a slight coincidental overrepresentation of missed Down syndrome cases). Serum concentrations of PAPP-A and f β -hCG were entered into the Astraia software to calculate MoMs and risks (calculations kindly provided with the help of Dr. R.J.M.…”

“…The reported gestational age was based on the fi rst day of the last menstrual period (LMP) or on the fetal crown-rump length (CRL) [9] .…”