NEW YORK (GenomeWeb) – The European Society of Human Genetics and the American Society of Human Genetics have issued a joint statement with recommendations regarding the implementation and innovation of noninvasive prenatal screening in clinical practice.
The groups published their statement, including 10 recommendations, this week in the European Journal of Human Genetics, in order to discuss the "emerging and future scenarios for NIPT-based prenatal screening from an ethical perspective," the authors wrote.
Since the first sequencing-based noninvasive prenatal test was launched in 2011, there has been significant adoption of such tests and they have expanded to screen not just for trisomies 21, 18, and 13, but also sex chromosome aneuploidies and microdeletion syndromes.
"NIPT has the potential of helping the practice better achieve its aim of facilitating autonomous reproductive choices, provided that balanced pretest information and non-directive counseling are available as part of the screening offer," the authors wrote.
First and foremost, the authors said, it is necessary to clarify the aim of NIPT as providing reproductive choice to women and their partners, rather than on preventing the birth of children with the conditions for which NIPT screens, which would "send a discriminatory message about the worth of the lives of people living with the relevant condition."
Similar to other recommendations on the use of NIPT, the authors suggest that a positive NIPT result always be confirmed with diagnostic invasive testing. In addition, they recommend that genetic counseling still be offered, including counseling for the possibility of identifying other abnormalities that the test is not specifically looking for.
However, while a number of commercial providers already include screening for sex chromosome aneuploidies and microdeletion syndromes, the authors do not recommend using NIPT for those purposes, which they say "not only raises ethical concerns related to information and counseling challenges but also risks reversing the important reduction in invasive testing achieved with implementation of NIPT for aneuploidy."
Another important factor, the authors said, is determining the framework in which NIPT is offered. There are a number of different scenarios in which NIPT is offered, each with its pros and cons. Currently, most professional organizations recommend offering NIPT only to women at a higher risk due to age or a positive combined first trimester screen, and as such NIPT is most frequently offered as second screening test after the first trimester screen. However, a number of publications have suggested that NIPT is as good, if not better, than existing first trimester screening tests, and could replace such tests.
Last year, for instance, researchers from the University of California, San Francisco and Columbia University presented data from over 15,000 pregnancies, showing that NIPT outperformed standard first trimester screening. A smaller study of over 2,000 women published in the New England Journal of Medicine yielded similar results.
However, the authors acknowledge that using NIPT as a replacement to standard first trimester screening has drawbacks in that it could potentially miss other abnormalities such as congenital cardiovascular defects and genetic syndromes like Noonan syndrome, and so suggest keeping nuchal translucency screening as a separate test.
The tradeoffs for the various scenarios of implementation should be evaluated as to how they "enable or impede meaningful reproductive choices and how they affect both the balance of benefits and burdens for pregnant women," the authors wrote.
As sequencing becomes cheaper and more accurate, there will be an increased need for a discussion about the scope of future prenatal screening. Currently, "there are strong ethical reasons for not expanding the scope of prenatal screening beyond serious congenital and childhood disorders," they wrote.
In countries where prenatal screening is offered as a public health program, governments should take an active role to ensure the responsible introduction of NIPT, the authors wrote.
And finally, in the future, it is possible that prenatal screening may lead to the possibility of fetal therapy, which will raise questions about "the relation between reproductive autonomy and parental responsibility."