Clinical Practice Guidelines Antenatal care - Module I

9.4 Other considerations in screening for fetal chromosomal abnormalities

Page last updated: 02 April 2013

Availability and uptake of screening

The range of screening tests available, screening policies and uptake of screening by women vary regionally (O’Leary et al 2006). Overall, approximately 50% of pregnant women participated in nuchal translucency screening in 2007–08 (Nisbet et al 2010). Studies in Victoria and Queensland have shown higher uptake of screening in metropolitan areas and in private health care and lower rates of diagnosis of Down syndrome in urban areas and public health care (Muggli et al 2006; Coory et al 2007). Lower rates of access to screening in rural areas may reflect lack of transport, low levels of support and income in these areas and women’s attitudes. However, it has been suggested that low uptake of testing among women from low socioeconomic groups reflects lower rates of informed choice rather than women’s attitudes towards screening (Dormandy et al 2005).

No data have been reported on the uptake of Down syndrome screening among Aboriginal and Torres Strait Islander women. However, a study at Royal Darwin Hospital in 1999 suggested that screening or diagnostic tests were rarely offered to Aboriginal women, including those in older age groups (Hunt 2004). A recent study into screening for chromosomal abnormalities among Aboriginal and Torres Strait Islander women (MSHR 2010) has highlighted the importance of providing information about screening and identified a number of challenges involved in offering screening, particularly in remote areas. These included late presentation in pregnancy, difficulties establishing accurate gestational age, limited consultation time to discuss the testing process, competing priorities in antenatal care, confusion about what has to be done and when, and organisational logistics (eg patient travel, where to send blood, referral procedures).

Practice point

x. There is inadequate access to screening for chromosomal abnormalities in rural and remote areas. Every effort should be made to support women in these areas to access screening.

Education

Health professionals caring for pregnant women should undertake continuing education regarding options available for screening for chromosomal abnormalities (see Section 9.5) and be aware of current screening tests available and the settings in which they can be implemented (HGSA & RANZCOG 2007).

Accreditation of ultrasound operators

The ability to achieve a reliable measurement of nuchal translucency depends on appropriate training and adherence to a standard technique to achieve uniformity of results among different operators (Nicolaides 2004). Accreditation of ultrasound operators to conduct nuchal translucency measurement should be either through the Fetal Medicine Foundation UK or through the Nuchal Translucency – Ultrasound, Education and Monitoring Project (NT-UEMP) administered through the Royal Australian and New Zealand College of Obstetricians and Gynaecologists (see Section 9.5).

Quality assurance

All laboratories must be accredited by the National Association of Testing Authorities (NATA). External and internal quality control measures should be in place.