Sequential Maternal Screening, Part 2, Serum
Method Description Describes how the test is performed and provides a method-specific reference
Sequential Maternal Screening, Part 1, Serum includes measuring the nuchal translucency (NT) and pregnancy-associated plasma protein A (PAPP-A). The NT and PAPP-A are compared to median values for a given gestational age and a multiple-of-the-median (MoM) is calculated for each. The MoM results are entered into a multivariate algorithm that includes the mother's age to derive risk factors for Down syndrome and trisomy 18. If the results from Part 1 fall below the screen cutoff, the results are held (not reported) until the sample from Part 2 is analyzed.
Sequential Maternal Screening, Part 2, Serum includes measuring alpha-fetoprotein (AFP), unconjugated estriol (uE3), human chorionic gonadotropin (hCG), and inhibin A. These measurements are compared to median values for a given gestational age and a MoM is calculated for each. Then, results from both trimesters (Part 1 and Part 2) are entered into a multivariate algorithm that includes the mother's age to derive risk factors for Down syndrome, trisomy 18, and neural tube defects. An interpretive report is provided.
PAPP-A, AFP, total beta hCG, uE3, and inhibin A assays are performed on the Beckman Access using an automated immunoenzymatic assays with paramagnetic separation and chemiluminescent detection (Package inserts: PAPP-A, AFP, total beta hCG, unconjugated estriol, and inhibin A. Beckman-Coulter Access, 2007)
Day(s) and Time(s) Test Performed Outlines the days and times the test is performed. This field reflects the day and time the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time required before the test is performed. Some tests are listed as continuously performed, which means assays are performed several times during the day.
Monday through Friday; 5 a.m.-5 p.m., Saturday; 6 a.m.-1 p.m.
Analytic Time Defines the amount of time it takes the laboratory to setup and perform the test. This is defined in number of days. The shortest interval of time expressed is "same day/1 day," which means the results may be available the same day that the sample is received in the testing laboratory. One day means results are available 1 day after the sample is received in the laboratory.
Maximum Laboratory Time Defines the maximum time from specimen receipt at Mayo Medical Laboratories until the release of the test result
Specimen Retention Time Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded
Performing Laboratory Location The location of the laboratory that performs the test