Penta Screen
Also known as: Maternal Serum Screen, Alpha-Fetoprotein, Maternal Serum
Use
Penta Screen is a maternal serum screening panel performed in pregnancy to assess risk for chromosomal abnormalities including Down syndrome (trisomy 21), trisomy 18, neural tube defects, and other adverse outcomes such as preeclampsia. This test combines five analytes—AFP, unconjugated estriol, human chorionic gonadotropin, dimeric inhibin A, and hyperglycosylated hCG (ITA)—along with maternal risk interpretation, to provide a comprehensive risk assessment. It is used to guide decisions regarding further diagnostic testing.
Special Instructions
Ordering requires use of the “Maternal Serum Screen Requisition” form and must be performed between 14.0 and 22.9 weeks gestational age; optimal collection window is 15.0–16.9 weeks. Specimens outside this window cannot be properly evaluated for neural tube defects, Down syndrome, or trisomy 18.
Limitations
Specimens collected before 14.0 weeks or after 22.9 weeks gestation are not properly evaluable for key anomalies like open neural tube defects, Down syndrome, or trisomy 18, limiting test interpretability. Moreover, maternal serum screening provides risk assessment only and is not diagnostic; false positives and false negatives may occur, and results should be confirmed with diagnostic testing when indicated.
Methodology
Immunoassay (Unknown)
Biomarkers
Result Turnaround Time
Not provided.
Related Documents
For more information, please review the documents below
Specimen
Serum
Volume
Not provided
Minimum Volume
Not provided
Collection Instructions
Performed between 14.0–22.9 weeks gestational age; optimal 15.0–16.9 weeks; must be ordered via Maternal Serum Screen Requisition.
Other tests from different labs that may be relevant