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MS WordPerinatologist Corner - C.E.U/C.M.E. Modules
Prenatal Genetic Screening – Serum and Ultrasound
Sponsored by The Indian Health Service Clinical Support Center
7. Quadruple marker screening
What about “quad
screening”? The use of four markers, “the quad screen”, should
be strongly considered. It is more sensitive, and has a lower false positive
rate (FPR), making it not only more “woman-friendly”, but also more
cost-effective. The best evidence for the quad screen comes from the SURUSS and FASTER
trials, which investigated first and second trimester “integrated” screening (see below). The quad screen has an overall detection rate of 85% for fetal DS. In younger women it has a FPR of 3%, and in women over age 35 it has a FPR of approximately 10%, considerably better than the “triple screen”. Many women want the highest detection rate possible, but for a majority of women, especially younger women, a lower FPR is very important. False positives generate considerable unnecessary anxiety, as well as more invasive testing, and the possibility of the loss of more normal fetuses. Likewise, the quad screen, despite an initial higher cost per individual test, may save resources because of the reduced need for referral, invasive testing, and travel. Laboratory cost analyses have demonstrated that, depending on population size, even performing four fewer amniocenteses a year will result in a cost saving because of the high cost of performing fetal karyotyping.
