Page URL:

Reflections on the ethical debate surrounding non-invasive prenatal genetic diagnosis

12 September 2011
By Professor Vardit Ravitsky
Assistant Professor, Département de médecine sociale et preventive, Université de Montréal
Appeared in BioNews 624
An up-and-coming technology will soon allow genetic testing of a fetus with a simple maternal blood test early in the first trimester of the pregnancy by isolating cell-free fetal DNA in the mother's plasma (1). Currently, obtaining reliable diagnostic genetic information requires invasive testing with CVS or amniocentesis. Both carry a risk of miscarriage (2) and are performed between weeks 10 and 20 of the pregnancy.

Women considering invasive testing must weigh the risk of losing a healthy fetus against the risk of bringing a fetus affected by a genetic condition to term. By eliminating the risk of miscarriage, this new technology promises tremendous benefits. It is a long-awaited achievement with the potential to revolutionise prenatal care.

At the same time, this technology is igniting an ethical debate regarding both its medical and non-medical uses. In the non-medical context, there are concerns that testing will lead society down a dangerous eugenic slippery slope where parents choose early abortions for frivolous reasons and select babies for desired traits.

A recent publication (3) confirming the test's reliability for determining the fetus' sex as early as seven weeks raised concerns about its non-medical use together with early sex-selective abortion in societies with a strong cultural preference for males.

Regulating early abortion isn't the appropriate way to address these ethical and social concerns. First-trimester abortion is - and should remain - a woman's prerogative. Her freedom to choose it should not be called into question.

Rather, these concerns should be seen as an opportunity to promote a social debate emphasising values like human dignity, equality and solidarity in our reproductive decision-making. Prospective parents should be encouraged to consider why they're choosing to terminate an otherwise wanted pregnancy and the implications of their choices for themselves, for their potential future child, and for society.

The future medical use of this new technology has also raised concerns. A risk-free maternal blood test may become accessible enough to become an inherent part of prenatal care.

Current prenatal care involves a two-step approach. Women are offered non-invasive screening using a maternal blood test combined with ultrasound. If the results raise concerns, the screening is followed by counselling about and consent for invasive diagnostic testing.

This two-step approach provides women with some built-in protection from exposure to unwanted diagnostic information. Counselling ensures women fully understand the risks of choosing invasive testing and the implications of the information they will obtain by choosing to take this risk.

Once the need for screening is eliminated, we can assume clinical practice will adopt a one-step approach in which a diagnostic blood test is as routine as ultrasound is today. But diagnostic testing without appropriate counselling and consent threatens pregnant women's autonomy to make informed decisions about what they wish to know about the fetus they are carrying (4).

Even within today's two-step approach, consent procedures for prenatal genetic screening are not appropriate and need enhancing (5). The transition to a one-step approach is likely to exacerbate this problem, particularly in light of the growing tendency toward the 'medicalisation' of pregnancy and pressures created by a medical system that favours testing.

These concerns about non-invasive testing are legitimate and deserve close examination. However, considering its tremendous benefits, they do not justify delaying its integration into clinical practice.

Rather, this is an important opportunity for clinicians, bioethicists and regulators to consider in advance possible risks and identify counselling and consent mechanisms to protect and promote autonomous decision-making.

1) Lo, Y. M. D., Chan, C.A., et al Maternal Plasma DNA Sequencing Reveals the Genome-Wide Genetic and Mutational Profile of the Fetus
Sci. Transl. Med. 2: 61ra91 |  2010
2) Tabor, A., Vestergaard, C.H. and Lidegaard, O. Fetal loss rate after chorionic villus sampling and amniocentesis
Ultrasound Obstet Gynecol. 34 (1):19-24 |  2009
3) Devaney, S. T., et al. Noninvasive Fetal Sex Determination Using Cell-Free Fetal DNA
JAMA 306 (6): 627-636 |  2011
4) Schmitz, D., Netzer, C. and Henn, W An offer you can't refuse? Ethical implications of non-invasive prenatal diagnosis. A reply to Ravitsky, V., Non-invasive prenatal diagnosis: an ethical imperative Nature Reviews Genetics 10: 733 October 2009
Nature Reviews Genetics 10: 515 |  08/09
5) Seavilleklein, V. Challenging the Rhetoric of Choice in Prenatal Screening
Bioethics 23 (1): 68-77 |  2009
11 June 2012 - by Dr Daniel Grimes 
Researchers have sequenced the entire genome of an 18 and a half-week-old fetus using DNA samples from the blood of its mother and saliva samples from its father. These findings provide a proof of principle that a fetus can be examined for genetic defects using non-invasive technologies...
9 January 2012 - by Victoria Kay 
There has been a rise in the number of British women choosing to give birth to fewer children following multiple pregnancy, leading to renewed calls for restrictions on the number of embryos implanted during IVF....
15 August 2011 - by Rose Palmer 
A simple blood test for pregnant women can accurately predict the sex of a fetus at seven weeks, much earlier than conventional techniques, new research has found. A systematic review and meta-analysis examined the results of 57 earlier studies that included more than 6,500 pregnancies...
13 December 2010 - by Julianna Photopoulos 
Scientists have scanned the entire DNA of an unborn child from the mother's blood sample for the first time to safely check for genetic disorders...
8 December 2008 - by Evelyn Harvey 
By Evelyn Harvey: A new method for early detection of genetic diseases in unborn babies using a simple blood test can detect the inherited condition beta-thalassemia, according to a study published in Proceedings of the National Academy of Sciences. Although the technique, which analyses cell free fetal DNA (cffDNA) present...
to add a Comment.

By posting a comment you agree to abide by the BioNews terms and conditions

Syndicate this story - click here to enquire about using this story.