NSGC on Down syndrome prenatal testing: What’s essential (and what’s not)

Three other professional organizations have issued statements on the newest form of prenatal testing for Down syndrome. But, the National Society of Genetic Counselors make clear what is essential  information expectant mothers should receive.

I have covered in previous posts the statements of the professional medical societies for obstetricians, medical geneticists, and those engaged in prenatal testing. At the beginning of this year, the National Society of Genetic Counselors (NSGC) became the second organization, after ACOG, to issue its statement on non-invasive prenatal screening (NIPS). Issued initially on-line, it is now available in print. The NSGC’s statement is consistent with the other statements, but adds to the understanding of how NIPS should be administered by expressly recognizing what is essential and by what it does not say, as well.

Like the statements from ACOG, ACMG, and ISPD, the NSGC seeks to make clear that NIPS remains just that: a screening test, not a diagnostic test. And, like other statements, the NSGC recommends that patients should be offered diagnostic testing after a positive NIPS result for confirmation purposes, since false positives and false negatives have been reported with NIPS.

As the national society for genetic counselors, NSGC, not surprisingly, also emphasizes the need for counseling in the administration of NIPS.

NSGC, though, makes very clear in its word choice the significance of pre-test counseling. NSGC recognizes, as ACMG did, that patients need to be counseled about the nature of NIPS, i.e. what it tests for, what it does not, and that its results are not diagnostic. But, NSGC further recognizes that because NIPS test results are superior to other existing screening tests for aneuploidy that “it is imperative that patients understand the significant implications of a positive result prior to undergoing” NIPS. (emphasis added). With a recent report finding that many women are not following up with invasive testing after an NIPS result, this admonition of NSGC’s is all the more justified.

Further, while the NSGC does emphasize the need for counseling, it is fair in its statement in recognizing that genetic counseling may not be available to all women for pretest counseling. Therefore, NSGC instead calls on at least “a qualified healthcare provider” to provide nondirective pretest counseling, i.e. not office staff personnel going through routine paperwork during a prenatal care visit. In the event of an abnormal NIPS result, though, the NSGC recommends that these patients “should receive genetic counseling from a certified genetic counselor.” NSGC is not alone in this recommendation; ACOG also recommends referral to genetic counseling following a positive NIPS result.

Moreover, unlike the other professional statements, NSGC further notes that patients being offered NIPS still should receive genetic counseling regardless of NIPS results. Like ACOG and ISPD, NSGC’s statement recognizes the validity of NIPS only for those women considered “high risk,” e.g. advanced maternal age, prior aneuploidy gestation, history of pregnancy loss, suggestive ultrasound markers. Therefore, women being offered NIPS by those actually following the professional statements are still in a high-risk category and should still be offered genetic counseling and invasive diagnostic testing. In this regard, NSGC distinguishes itself from the other society statements. (Though, to be fair, ACOG and ACMG statements did not supersede their pre-existing guidelines on prenatal testing, which recommended all women be offered invasive testing regardless of age).

NSGC further distinguishes itself by expressly noting what is essential and by what NSGC’s statement does not say.

The NSGC statement makes clear that:

NSGC firmly believes that reproductive decisions should be made in the context of unbiased and comprehensive information, free from discrimination or coercion.

* * *

Both NSGC and disability advocacy groups deem it essential that pregnant women receive unbiased, value neutral information regarding prenatal genetic conditions. This information and support enables a pregnant woman and her family to determine an outcome that fits within their personal, cultural, religious, and social context.

None of the other statements deem what is essential in such a clear way.

Further, the NSGC statement is noteworthy for what it does not say. The NSGC statement uses phrases like “positive NIPS result” and “high risk” sparingly, since they can suggest an inaccurate meaning.

As ACOG Practice Bulletin No. 77 notes, screening results should not be referred to as “positive” or “negative.” Screening results are recalculations of probabilities of having the tested-for condition, and their results should be relayed in a probability fashion, not as “positive” or “negative.”

Similarly, the very word “risk” suggests something that should be avoided. Very few people describe a possibility of a good or desired thing as a “risk.” We do not “risk” winning the lottery; we take a chance at winning the lottery; or, we hope we will win the lottery. Particularly in the medical context, “risk” almost always is something to be avoided, e.g. “I got tested to find out my risk for heart attack or colon cancer.”

In its concluding recommendations, NSGC conscientiously describes women “who have other factors suggestive of a chromosome abnormality” to inform what it means by the use of the phrase “increased risk.”

The NSGC statement adds yet another perspective, which in turn, provides a fuller view of how to administer NIPS. Counseling is rightly emphasized, before accepting testing and regardless of test results, with a description of who should do the counseling and what it should consist of. And, the NSGC is clear on what is essential: unbiased, value neutral information about prenatal genetic conditions. If followed, the NSGC recommendations will result in a more ethical administration of prenatal genetic testing.