ACOG Guidelines Recommend NIPT for All Pregnancies Regardless of Risk
25.08.2020NEW YORK - The American College of Obstetricians and Gynecologists has issued a new set of guidelines, recommending that prenatal aneuploidy screening be offered to all pregnant people regardless of their age or other risk factors.
Although the document endorses multiple methods — both the traditional serum protein screen with or without nuchal translucency ultrasound and the newer generation of cell-free DNA-based non-invasive tests — ACOG specifically stated in the new guidelines that cfDNA assays, known as non-invasive prenatal tests, offer superior sensitivity and specificity.
Previously, the organization had only recommended the use of NIPT in individuals 35 and older or with other known risk factors. Currently marketed cfDNA-based NIPT options include Natera's Panorama test, Roche's Harmony assay, Progenity's Innatal, the MaterniT21 Plus test originally developed by Sequenom and now marketed by Laboratory Corporation of America, and Myriad Genetics' Prequel, among others.
Natera, which has become a leader in the market, saw its share price rise 15 percent in Monday trading following the news of the new ACOG guidelines, which were published by the college as Practice Bulletin 226.
In an note to investors on Monday, analyst Alexander Nowak from investment bank Craig-Hallum wrote that he expects the new guidelines to help increase adoption of Panorama among average-risk women and to push insurers that have held back from covering the test in this population to come around.
According to Nowak, ACOG's previous guideline endorsing cfDNA tests for high-risk pregnancies led to an increase in market penetration to between 60 and 80 percent for Natera in this population.
Nowak estimated that Natera's penetration among average-risk pregnancies is currently about 30 percent and said that with the new guidelines now in place, this should now increase to similar levels as the firm has seen in high-risk women.
Natera initially began offering its test to average-risk women several years ago and published a large study showing high performance last year. Nevertheless, the company and its competitors have struggled to persuade private payors to cover tests in this broader population.
"This new bulletin changes everything. It should make the payers fall in line and lead to physicians actively recommending NIPT to all patients," Nowak wrote.
Steven Mah of investment bank Piper Sandler echoed the same takeaway for the larger NIPT field, calling the ACOG decision the "long-anticipated endorsement" that Natera, Progenity, Myriad, Illumina, and others have been waiting many years for. "We expect that … payers will [come to] regularly reimburse average-risk NIPT, however, exact timing may vary," he added.
Hesitation around the use of NIPT in average-risk pregnancies has hinged on concern around the predictive value of these tests in a population where chromosomal abnormalities are so rare. Although the false-positive rate of NIPT is significantly lower than the alternative serum screening option, there was also worry that individuals might falsely interpret positive NIPT aneuploidy results as diagnostic, making decisions about their pregnancy without follow-up confirmatory tests like amniocentesis.
In its new recommendations, ACOG specified that if a patient offered prenatal screening opts to go forward, they should be given one test — either NIPT or a serum screen — and should not have multiple tests performed simultaneously.
Although the guidelines describe cell-free DNA as "the most sensitive and specific screening test for the common fetal aneuploidies," ACOG also stressed that physicians should be aware that NIPT has the potential for false-positive and false-negative results and is "not equivalent to diagnostic testing."
"Patients with a positive screening test result for fetal aneuploidy should undergo genetic counseling and a comprehensive ultrasound evaluation with an opportunity for diagnostic testing to confirm results," ACOG recommended.
The authors acknowledged that individuals unwilling to undergo invasive diagnostic tests after a positive serum screen might want to use cell-free DNA screening as follow-up. In such cases, patients "should be informed that this approach may delay definitive diagnosis and will fail to identify some fetuses with chromosomal abnormalities," the group wrote.
According to the authors, the residual risk of having a chromosomal abnormality after an abnormal screening test and a normal NIPT follow-up has been reported to be about 2 percent.
Finally, ACOG stated that patients with a negative screening test result should be made aware that this "substantially decreases their risk of the targeted aneuploidy but does not ensure that the fetus is unaffected." Those whose results can't be reported because of a laboratory test failure or are or are uninterpretable should be informed that such failures can be associated with elevated risk of aneuploidy and be offered comprehensive follow-up and diagnostic testing.
