Nicolas Fries1, Laurent J Salomon2,3, Françoise Muller4,5, Sophie Dreux4,5, Véronique Houfflin-Debarge6,7, Philippe Coquel3, Pascale Kleinfinger8, Marc Dommergues9,10. 1. Collège Français d'Echographie Foetale (CFEF), Montpellier, France. 2. Maternité, Hôpital Necker-Enfants Malades, AP-HP, Université Paris-Descartes, Paris, France. 3. Collège d'Evaluation des Pratiques Professionnelles en Imagerie Médicale (CEPPIM), Paris, France. 4. Biochimie-Hormonologie, Hôpital Robert Debré, AP-HP, Paris, France. 5. Association des Biologistes Agréés (ABA), Paris, France. 6. Département d'Obstétrique, CHU Lille, Lille, France. 7. Collège National des Gynécologues Obstétriciens Français (CNGOF), Paris, France. 8. Association des Cytogénéticiens de Langue Française (ACLF), Paris, France. 9. Gynécologie-Obstétrique, Hôpital Pitié-Salpétrière AP-HP, Paris, France. 10. Université Pierre et Marie Curie Paris 6, Paris, France.
Abstract
OBJECTIVE: To assess the distribution of nuchal translucency (NT) measurements following a national policy without credentialing and its impact on first-trimester Down syndrome screening (DSS) detection rate. METHOD: All first-trimester DSS data recorded in France (2010-2014) were collected by the laboratories in charge via an Internet database (https://www.bionuqual.org/echo.php). There was no minimal requirement for image quality to allow sonographers to enter the screening process. A subgroup of DSS with complete DS follow-up corresponded to 1614 sonographers. Based on the distribution of maternal age, DS detection rate was calculated and split as a function of the distribution of NT multiple of the median (MoM). RESULTS: Four thousand nine hundred forty-three sonographers performed 2,337,372 NT measurements. Median NT expressed in MoM was 0.83. Screenings with complete follow-up consisted of 197,417 screenings, in which DSS detection rates were respectively 70.4%, 70.9%, 79.4%, 87.7%, and 79.5% for the following median NT MoM ranges: <0.7, 0.70 to 0.79, 0.80 to 0.89, 0.90 to 0.99, and >0.99 (trend χ = 12.21; P = .0158). CONCLUSION: In France, following a policy of quality assessment without standardized credentialing, the distribution of NT measurements did not fit the expected distribution. Down syndrome detection rate was 10% lower in screenings by sonographers with a median NT < 0.80 MoM.
OBJECTIVE: To assess the distribution of nuchal translucency (NT) measurements following a national policy without credentialing and its impact on first-trimester Down syndrome screening (DSS) detection rate. METHOD: All first-trimester DSS data recorded in France (2010-2014) were collected by the laboratories in charge via an Internet database (https://www.bionuqual.org/echo.php). There was no minimal requirement for image quality to allow sonographers to enter the screening process. A subgroup of DSS with complete DS follow-up corresponded to 1614 sonographers. Based on the distribution of maternal age, DS detection rate was calculated and split as a function of the distribution of NT multiple of the median (MoM). RESULTS: Four thousand nine hundred forty-three sonographers performed 2,337,372 NT measurements. Median NT expressed in MoM was 0.83. Screenings with complete follow-up consisted of 197,417 screenings, in which DSS detection rates were respectively 70.4%, 70.9%, 79.4%, 87.7%, and 79.5% for the following median NT MoM ranges: <0.7, 0.70 to 0.79, 0.80 to 0.89, 0.90 to 0.99, and >0.99 (trend χ = 12.21; P = .0158). CONCLUSION: In France, following a policy of quality assessment without standardized credentialing, the distribution of NT measurements did not fit the expected distribution. Down syndrome detection rate was 10% lower in screenings by sonographers with a median NT < 0.80 MoM.