PATIENT CONSULTATION AND COUNSELLING IN NUCHAL TRANSLUCENCY ASSESSMENT

Margo Harkness DMU FIR MAppSc MBA, Senior Lecturer in Medical Ultrasound, Centre for Medical, Health and Environmental Physics, Queensland University of Technology (QUT) and Senior Sonographer, Brisbane Ultrasound for Women, Spring Hill, Queensland; Dr Gary Pritchard MBBS FRACOG DDU, Obstetric and Gynecologic Sonologist, Brisbane Ultrasound for Women, Spring Hill, Queensland.

Introduction
Chromosomal abnormalities are thought to be present in approximately 6% of zygotes with many of the affected cells either never implanting or spontaneously aborting. Of the pregnancies that progress, the most common chromosomal defects result in a range of phenotypic expressions and structural abnormalities (1).
A number of screening and diagnostic tests are available that can be applied in pregnancy in an attempt to identify the chromosomally abnormal (aneuploid) fetus (2). Trisomy 21, or Down Syndrome, is the most common chromosomal abnormality and represents approximately 50% of aneuploid fetuses. It is widely known about in the general population and the cause of considerable anxiety in many pregnant women. Much of the antenatal chromosome testing performed is primarily for the detection of Trisomy 21. The reported accuracy of the screening tests vary considerably and the invasive diagnostic tests carry a risk of pregnancy loss. In order for the tests to be used in the most appropriate and cost-effective way, the relationships between the tests needs to be understood by ultrasound practitioners, patients and clinicians.
This paper presents a flow chart of possible decision paths, combining both screening and diagnostic tests to aid in the consultation of patients considering investigation for chromosomal defects. The flow chart was developed initially as a guide for the personnel at Brisbane Ultrasound for Women (MH and GP) to discuss the role of nuchal translucency assessment in the detection of aneuploidy. It soon became apparent that patients gained increased insight and understanding from its use and it is used as the basis for discussion of results with the patient. They are given a copy to take away for further consideration and are encouraged to call the practice if they have further questions. The flow chart is not given to patients as a “stand alone” information sheet, as this is not its purpose. It is designed to be used as a discussion tool and it is inappropriate for it to be used in any other way.

Citation
Harkness M and Pritchard G. Patient consultation and counselling in nuchal translucency assessment. ASUM Bulletin 2001.2:17-20.