The 3‑marker (triple) test is a second‑trimester maternal blood screen measuring alpha‑fetoprotein (AFP), human chorionic gonadotropin (hCG) and unconjugated estriol (uE3). It assesses risk for Down syndrome, trisomy 18 and neural tube defects, typically done around 15–20 weeks. Results indicate risk only; abnormal findings prompt further evaluation with ultrasound, noninvasive testing or diagnostic procedures.

The graph test plots serial quantitative (beta) hCG blood results over time to assess early pregnancy. In a normal intrauterine pregnancy hCG typically rises, roughly doubling every 48–72 hours in early weeks. Slower increases, plateaus, or falling levels suggest possible nonviable or ectopic pregnancy. Clinicians use repeated blood draws and the trend graph to diagnose viability and guide management.

The Triple Marker Test measures maternal serum hCG (usually the beta‑hCG subunit). Results are given as absolute concentration and as multiples of the median (MoM) for gestational age. Values around 0.5–2.0 MoM are generally typical. Elevated hCG (high MoM) raises suspicion for Down syndrome; low hCG can be seen with other chromosomal or placental issues and requires combined-marker interpretation.

A positive triple screen (maternal AFP, hCG, unconjugated estriol) indicates an increased risk for fetal conditions—most commonly Down syndrome (trisomy 21), Edwards syndrome (trisomy 18), or neural tube defects. It is a screening test, not diagnostic; false positives occur. Follow-up with ultrasound, cell-free DNA or diagnostic testing (CVS/amniocentesis) and review of gestational age and maternal factors is recommended.

A positive Triple Marker Test indicates an increased risk of chromosomal abnormalities (like Down or Edwards syndromes) or neural tube defects, but it is not diagnostic. Follow-up typically includes a detailed ultrasound, noninvasive prenatal testing (cell‑free DNA) and, if needed, diagnostic testing (CVS or amniocentesis) and genetic counseling. Results can be affected by gestational age, maternal weight, diabetes and multiple pregnancy.

Down syndrome in pregnancy is a genetic condition caused by an extra copy of chromosome 21 (trisomy 21) in the fetus. It commonly causes characteristic facial features, developmental and intellectual disability, and increased risk of congenital heart and gastrointestinal defects. Risk rises with maternal age. Prenatal care offers screening (first‑trimester combined, cell‑free DNA) and diagnostic tests (CVS, amniocentesis) and counseling for parents.