The role of informed consent in aneuploidy screening


  • M. C. Treadwell

    Corresponding author
    1. Department of Obstetrics and Gynecology, University of Michigan Medical School, F4835 Mott-0624, 1500 E. Medical Center Drive, Ann Arbor, MI 48109, USA
    • Department of Obstetrics and Gynecology, University of Michigan Medical School, F4835 Mott-0624, 1500 E. Medical Center Drive, Ann Arbor, MI 48109, USA
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In light of the increased reliance on non-invasive aneuploidy screening strategies it is important to define those factors related to the understanding of these tests by the women being screened. Previous studies have shown that patients' knowledge regarding maternal serum screening tests performed for trisomy 21 risk assessment is fragmentary1. The article by Khoshnood et al. in this issue attempts to better define both patients' cognitive knowledge base and those factors that influence the understanding of patients undergoing maternal serum screening and nuchal translucency (NT) screening in pregnancy2.

To improve patients' understanding of the clinical relevance of screening-test results, it is imperative that they be aware of the tests being performed. Implementing standardized informed consent for performing maternal serum screening appears to have improved the level of understanding for serum screening in France. Despite this improvement, a significant segment of the screened population still did not correctly interpret the results of the screening test. There appears to be even less understanding of the implications of first-trimester NT screening. The differences between understanding of the first- and second-trimester screening test results may reflect the lack of standardized informed consent required for the NT screening in this population, and provides support for instituting standardized informed consent.

Consistent with previous studies, women with more education seem to have a better understanding of the implications of the screening tests3. This appears to be especially true for women between the ages of 35 and 37. For women older than 38, the authors describe a tendency to undergo invasive testing and forego the screening tests entirely or to proceed with invasive testing despite reassuring results of non-invasive screening tests. Whether this preference for invasive testing is due to a lack of understanding, as suggested by the authors, or perhaps to other factors is uncertain. The preference for invasive testing in women attending private clinics, or over the age of 38 years, may reflect a different set of patient priorities in this population, with the risk of an invasive procedure being offset by the perceived impact of having an affected child, regardless of assigned risk. Ensuring that screened patients have pre-test information presented to them at an educationally-appropriate level may eliminate biases due to cognitive disparities. Obviously, any non-invasive aneuploidy screening strategy must be based upon clinically relevant patient knowledge (i.e. true informed consent) and must minimize patient ignorance related to the clinical implications of the test results. Ultimately, the patient should be able to determine the appropriate balance of risk and benefit for invasive testing, which may or may not be consistent with the arbitrary cut-offs we use to interpret test results.

Patient autonomy can be enhanced by the use of first-trimester aneuploidy risk assessment. Well-informed patients use this information to make decisions about subsequent invasive testing4. The availability of first-trimester screening is also associated with less patient anxiety when compared to groups not offered the opportunity for screening5. Maximizing the patient benefits of autonomy and decreased anxiety, independent of enhanced risk assessment, requires the dissemination of appropriate and accurate information. Khoshnood et al. highlight the importance of teaching our patients the rationale for and implications of the screening tests we are offering them. This example of true informed consent will allow them to make appropriate decisions for more definitive testing, will afford them enhanced autonomy and will relieve them of some of the anxiety potentially associated with pregnancy.