Auditing ultrasound assessment of fetal nuchal translucency thickness: a review of Australian National Data 2002-2008

Abstract

Background: Nuchal translucency (NT) measurement is the ultrasound component of first trimester combined screening for Down syndrome. In 2002, a NT ultrasound education and monitoring program was established in Australia. Between 2002 and 2008, a total of 728,502 NT scans were audited through this process. OVERALL AIM: To audit the availability and performance of certified operators measuring NT following implementation of the Australian education and monitoring program in 2002.

Methods: Retrospective review of the central database that is used to monitor performance of individuals and practices performing NT scans in both public and private practice settings throughout Australia between 2002 and 2008. The performance of operators was assessed by a widely used international standard - that 40-60% of NT measurements should be above the median value for gestational age.

Results: The number of certified operators has increased (from 184 in 2002 to 477 in 2008). There is wide variation between states in the number of operators per birth. The percentage of certified operators with a measurement distribution meeting the international standard has increased from 40% in 2002 to 55% in 2008. Greatest improvement has been seen in operators performing 30-199 scans per year. There has been no overall improvement in performance over the last three audit cycles.

Conclusions: The number of operators certified to perform the NT scan has increased since 2002, although availability in some states remains low. An initial improvement in performance of operators appears to have reached a plateau. It is time to become more proactive in engaging operators in the audit cycle.