1T Aneuploidy Screen 1TANEU
Synonyms |
MFST1 |
Allscripts (AEHR) Order Name |
1T Aneuploidy Screen |
Sunrise Clinical Manager (SCM) Order Name |
1T Aneuploidy Screen |
EPIC Order Name |
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Clinical Info |
1T Aneuploidy Screen is a first trimester screening test for the three most common fetal aneuploidies, trisomies 21, 18 and 13. |
Specimen Type |
Blood |
Specimen Volume |
3 mL serum ( 0.5 mL min) |
Container |
Gold Top Tube |
Collection Instructions |
Container/Tube: Gold Top Tube |
Transport Instructions |
Room Temperature |
Specimen Stability |
6 days Room Temperature |
Methodology |
Time-Resolved Amplified Cryptate Emission (TRACE) |
Days Performed |
Monday - Friday TAT 1-2 Days |
Performing Laboratory |
Northwell Health Laboratories |
CPT |
82105- AFP |
PDM |
241467 |
Result InterpretationRisk Calculation: Each analyte level is converted into a multiple of the GA specific median (MoM) and is then adjusted based on the patient's race, weight, diabetic status, and smoking status. The likelihood ratio for each analyte is calculated as the ratio of the probability density function in affected pregnancies divided by the probability density function for unaffected pregnancies. Patient specific risks for Down syndrome and trisomy18/13 are calculated using Bayes’ rule. The prior risk, based on demographic factors, is multiplied by the likelihood ratios for each maker appropriate for the condition screened. An interpretive risk report including the patient's analyte levels, cut-off values and risks for trisomy 21 and trisomies 18/13 will be provided. Down’s Syndrome (trisomy 21) Interpretation: The risk cut-off is set equal to the first-trimester risk of a 35 year old (1/250). This test may detect 98% of cases with Down’s syndrome at an approximate 2% false positive rate. Edward Syndrome (trisomy 18)/Patau Syndrome (trisomy 13) Interpretation: The risk cut-off is set equal to 1/100. This cut-off is chosen to balance the detection and false positive rates. This test may detect 95% of cases with T18/13 at an approximate 0.5% false positive rate.
Test Follow Up: If the patient's risk is less than the cut-off risk the test is considered "Within Normal Range" and no further action is required. If the patient’s risk is greater than or equal to the cut-off risk the test is considered "Increased Risk". Patients at increased risk are offered detailed ultrasound, NIPT and/or diagnostic amniocentesis. Upon receiving maternal serum screening results, all information used in the risk calculation should be reviewed for accuracy (ie, weight, diabetic status, gestational dating). If any information is incorrect, the laboratory should be contacted for recalculation of the estimated risks. ‘Within Range’ risk results typically do not warrant further evaluation. Ultrasound is recommended to confirm dates for ‘Increased Risk’ results. If ultrasound yields new dates that differ by at least 7 days, a recalculation should be considered. The screen results are dependent on accurate information for gestation, race, IDD, and weight. Inaccurate information can lead to significant alterations in the estimated risk. In particular, erroneous assessment of gestational age can result in false-positive or false-negative screen results. Because of its increased accuracy, the determination of gestational age by ultrasound is recommended, when possible, rather than by last menstrual period. Disclaimers This is a screening test, not a diagnostic test. A ‘Within Range’ risk result indicates low risk for the conditions screened but does not guarantee the absence of those conditions or other abnormalities. An ‘Increased Risk’ result indicates an increased risk for the condition screened but does not infer a definitive diagnosis. Cautions Valid measurements of maternal serum markers cannot be made after CVS or amniocentesis. Triplet and higher order multiple pregnancies cannot be interpreted. In rare cases, some individuals can develop antibodies to mouse or other animal antibodies (often referred to as human anti-mouse antibodies [HAMA] or heterophile antibodies), which may cause interference in some immunoassays. Caution should be used in interpretation of results and the laboratory should be alerted if the result does not correlate with the clinical presentation. Each center offering maternal serum screening to patients should establish a standard screening protocol, which provides pre- and post-screening education and appropriate follow-up for ‘Increased Risk’ results.
Clinical References 1. ACOG Practice Bulletin 226 - Screening for Fetal Chromosomal Abnormalities. Obstet Gynecol VOL. 136, NO. 4, OCTOBER 2020. 2. NJ Wald, C Rodeck, AK Hackshaw, J Walters, L Chitty, AM Mackinson. First and second trimester antenatal screening for Down’s syndrome: the results of the Serum, Urine and Ultrasound Screening Study (SURUSS). (2003) Health Technology Assessment Vol. 7: No.11. 3. Fergal D. Malone, M.D., Jacob A. Canick, Ph.D., Robert H. Ball, M.D., David A. Nyberg, M.D., Christine H. Comstock, M.D., Radek Bukowski, M.D., Richard L. Berkowitz, M.D., Susan J. Gross, M.D., Lorraine Dugoff, M.D., Sabrina D. Craigo, M.D., Ilan E. Timor-Tritsch, M.D., Stephen R. Carr, M.D., Honor M. Wolfe, M.D., Kimberly Dukes, Ph.D., Diana W. Bianchi, M.D., Alicja R. Rudnicka, Ph.D., Allan K. Hackshaw, M.Sc., Geralyn Lambert-Messerlian, Ph.D., Nicholas J. Wald, F.R.C.P., and Mary E. D’Alton, M.D., for the First- and Second-Trimester Evaluation of Risk (FASTER) Research Consortium* (2005) First-Trimester or Second-Trimester Screening, or Both, for Down’s Syndrome. N Engl J Med 353;19 2001-2011. 4. Carmichael JB, Liu HP, Janik D, Hallahan TW, Nicolaides KH and Krantz DA. Expanded conventional first trimester screening. Prenatal Diagnosis 2017, 37, 802–807. This test was developed, and its performance characteristics determined by Northwell Health Laboratories. It has not been cleared or approved by the Food and Drug Administration. The methods and performance characteristics have been reviewed and approved by the New York State Department of Health |
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