|Values are valid only on day of printing.|
Prenatal screening for Down syndrome and trisomy 18
Prenatal screening for neural tube defects (this is only applicable to Part 2 [second trimester] of the test)
Sequential maternal screening is a 2-part test, with first- and second-trimester components. It requires a nuchal translucency (NT) measurement and blood draw in the first trimester. If the result from Part 1 indicates a risk for Down syndrome that is higher than the screen cutoff, the screen is completed and a report is issued. If Part 1 results are negative, an additional blood draw in the second trimester is required (see SEQF / Sequential Maternal Screening, Part 2, Serum). If the second specimen is not received for sequential screening, the results are uninterpretable and no maternal risk will be provided.
See Sequential Maternal Serum Screening Testing Process in Special Instructions.
Two-Site Immunoenzymatic (Sandwich) Assay