Multiple Marker Screening (MMS) measures specific substances in a pregnant woman’s blood originating from the fetus, the placental tissue, or a combination of both. MMS determines your risk for having a child with Down syndrome, trisomy 18 and neural tube defects
(spina bifida and anencephaly). The test detects approximately 80 percent of Down syndrome, 60% of cases of trisomy 18 and 80% of cases of open spina bifida.
What if the MMS screening test shows an increased risk?
If your test results show an increased risk, then you will be counseled by your doctor and/or one of our genetic counselors about the results. The first step may be to have an ultrasound examination. Sometimes the blood test results are higher or lower than we expect simply because your pregnancy is not quite as far along or is more advanced than we calculated by your last menstrual period. In this case, the expected date of your delivery and the interpretation of your test may be changed after the ultrasound scan. If your risk for Down syndrome is still increased, you may decide to have additional screening with cell-free DNA.