Web: | mayocliniclabs.com |
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Email: | mcl@mayo.edu |
Telephone: | 800-533-1710 |
International: | +1 855-379-3115 |
Values are valid only on day of printing. |
First-trimester prenatal screening for Down syndrome (trisomy 21) and trisomy 18
Sequential maternal screening is a 2-step test, with first- and second-trimester components. It requires a nuchal translucency (NT) measurement and blood collection 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 the results from part 1 are negative, an additional blood collection in the second trimester is required (see SEQB / 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.
The following are available in Special Instructions:
-Sequential Maternal Serum Screening Testing Process
-Prenatal Aneuploidy Screening and Diagnostic Testing Options Algorithm
Immunoenzymatic Assay