Sequential Screen: Overall Detection Rate: 94%. False Positive: 5.5%
for Down syndrome

Sequential Screen | Fß

Eurofins NTD, LLC. Sequential Screen | Fß test reliably assesses a mother's risk for having a baby with Down syndrome, trisomy 18, trisomy 13 and open neural tube defects (ONTDs) during the first and second trimesters of pregnancy. Performed between 11 weeks, 1 day and 13 weeks, 6 days, and then again between 15 weeks and 21 weeks, 6 days gestation, the Sequential Screen | Fß uses data from 2 blood tests (biochemistry) and an ultrasound examination (biophysical) which yield two risk assessments that physicians may present to their patients during the first trimester and the second trimester.

Part 1 of the Sequential Screen | Fß

A maternal blood sample is analyzed for three biochemical markers in the first trimester: alpha fetoprotein (AFP), free beta human chorionic gonadotropin (free beta hCG) and pregnancy associated plasma protein-A (PAPP-A).

The ultrasound examination in the first trimester confirms the fetus' gestational age and measures the nuchal translucency (NT), or the fluid accumulation behind the fetus' neck. These combined biochemical and biophysical markers yield the most sensitive screening results possible at the earliest point during the pregnancy, achieving a 93% detection rate at a 5% false positive rate for Down syndrome (and a 95% detection rate at a 0.3% false positive for trisomy 18 and 13). Part 1 of the Sequential Screen | Fß is essentially the same as the First Trimester Screen | Fß test.

Part 2 of the Sequential Screen | Fß

Part 2 of the Sequential Screen | Fß is performed in the second trimester of pregnancy, between 15 weeks and 21 weeks, 6 days gestation. This part of the test analyzes 4 biomarkers found in the mother's serum - alpha-fetoprotein (AFP), free beta hCG, unconjugated estriol, and inhibin-A. When the measurements from Part 2 are combined with those from Part 1, 95% of Down syndrome cases are detected at a 5.8% false positive rate and 95% of trisomy 18 and trisomy 13 cases are detected at a 0.3% false positive rate. Sequential Screen | Fß also screens for ONTDs, which can only be done in the second trimester. This test detects 90% of cases of open spina bifida and 98% of cases of anencephaly.

(References 13,26,31 Data on file, Eurofins NTD, LLC.)


DISCLAIMER: This test is a part of a lab service offering provided by Eurofins NTD, LLC. This test was developed and its performance characteristics determined by Eurofins NTD, LLC. It has not been cleared or approved by the U.S. Food and Drug Administration. The methods and performance characteristics have been reviewed and approved by the New York State Department of Health. The test results do not eliminate the possibility that this pregnancy may be associated with birth defects or pregnancy complications including preeclampsia, pre-term delivery and low birth weight. The multiple of the median and risk results provided in the test report are dependent on the accuracy of the demographic and ultrasound information provided. The ordering physician should ensure that the ultrasound information has been obtained from a sonographer who is credentialed by and participating in a uterine artery Doppler quality review program such as FMF. Eurofins NTD, LLC. assumes no responsibility for ensuring that the ultrasound information has been obtained by a properly credentialed sonographer, including verification or updates to credentialing status.