PrenatalObstetrics & Gynecology

Triple Screen Marker Test

Normal Range
Screen Negative (Risk below cutoff)
Sample Type
Serum
Fasting
No
Unit
MoM

Function

The Triple Screen, also known as the Kettering test or Bart's test, is a prenatal blood test performed during the second trimester (usually between weeks 15 and 20). It measures three substances in the mother's blood: Alpha-fetoprotein (AFP), Human Chorionic Gonadotropin (hCG), and Unconjugated Estriol (uE3).

Why it is Ordered

This is a screening test (not a diagnostic test) used to evaluate the statistical risk that the fetus may have certain chromosomal abnormalities or neural tube defects. It is offered to all pregnant women but is particularly relevant for those over age 35 or with a family history of birth defects.

Associated Conditions

  • Neural Tube Defects (NTDs): Such as spina bifida or anencephaly (associated with high AFP).
  • Trisomy 21 (Down Syndrome): Often associated with low AFP, high hCG, and low uE3.
  • Trisomy 18 (Edwards Syndrome): Often associated with low levels of all three markers.
  • Multiple Gestation: Carrying twins or triplets can naturally elevate these levels.

Check Your Result

Check Your Result

Interactive
MoM

Enter your lab result to see where you stand compared to the standard reference range.

Why Context Matters

The Triple Screen has a significant false-positive rate. Results are heavily dependent on the accurate calculation of gestational age. If the pregnancy is even a few days further along or behind than estimated, the results will be skewed. A 'positive' screen should always be followed by a second opinion involving a high-resolution ultrasound or a diagnostic test like Amniocentesis.

Lab ranges are statistical averages, not biological laws. "Normal" for a 20-year-old male isn't normal for a 60-year-old female.

Clinical References

Source-of-truth databases and clinical guidelines for Triple Screen Marker Test:

Research & Guidelines

Related Indicators

DR

Medically Reviewed by Dr. Binoy Babu, MBBS

Board Certified Doctor • 10+ Years Clinical Experience

Dr. Babu is a practicing physician dedicated to empowering patients with clear, actionable medical information. He founded 2opi to bridge the gap between complex lab reports and patient understanding, ensuring everyone has access to a reliable second opinion.

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