Obstetric Groups Still Don’t Endorse Universal Use of NIPT, But Expand Access

Conventional screening for common aneuploidies remain the “most appropriate” choice for first-line screening for most women in the general obstetric population, according to a committee opinion published online June 26 by the American College of Obstetricians and Gynecologists (ACOG) and the Society for Maternal-Fetal Medicine. However, the groups say that noninvasive prenatal screening (NIPT) using cell-free DNA (cfDNA) methodologies offers “tremendous potential” as a screening method for fetal aneuploidy and that any patient, regardless of her risk status, may choose cfDNA analysis as a screening strategy for common aneuploidies (trisomies 13, 18, and 21).

NIPT has been hailed as a major breakthrough in bringing sequencing-based testing into routine care, given the speed it has been adopted into practice since its commercial introduction.

The new statement expands the use of NIPT, compared to a 2011 ACOG recommendation, which stated that cfDNA testing should not be offered to low-risk women and only used in high-risk women. Yet, the new statement still falls short of universally endorsing the test, citing the limitations of cfDNA screening performance and limited data on cost-effectiveness in the low-risk obstetric population. The groups say that more recent data shows the tests’ sensitivity and specificity in the general obstetric population are similar to the levels previously published for the aforementioned high-risk population, but that more false-positive test results are reported owing to the lower prevalence of aneuploidy in the general obstetric population.

The recommendation recognizes that patient choice is paramount to screening method choice, and that to make an informed choice women should be counseled regarding the limitations and benefits of NIPT. Patient-clinician discussion should include alternative methods of testing, as well as the option to not test at all.

The recommendations acknowledge that cfDNA testing only screens for the common trisomies (not neural tube defects or ventral wall defects, which should be tested using maternal serum alpha-fetoprotein screening and ultrasound). It also calls for further counseling and diagnostic testing for women with positive results, as well as women with indeterminate results.

The groups recommend against cfDNA testing in patients with multiple gestations and against cfDNA testing for microdeletion syndromes, due to a lack of clinical validation.

Takeaway: While falling short of universal recommendation of cfDNA-based NIPT, professional groups say that regardless of individual risk, any informed woman can choose to have the test.