A penta marker test is a prenatal screening blood test that measures five maternal serum markers—typically AFP, hCG, unconjugated estriol, inhibin A and PAPP‑A—to estimate the risk of chromosomal abnormalities (like Down and Edwards syndromes) and neural tube defects. It indicates risk, not a diagnosis; abnormal results prompt further diagnostic testing and specialist counseling.

A 3‑marker (triple) test is a second‑trimester maternal blood screen measuring AFP, hCG and unconjugated estriol. Done about 15–20 weeks, it estimates risk for neural tube defects and chromosomal conditions (e.g., Down or Edwards syndrome). It’s a screening—not diagnostic—so abnormal results prompt ultrasound and definitive testing (cell‑free DNA or amniocentesis) for confirmation.

The double‑marker is a first‑trimester screen (about 9–14 weeks) measuring two blood markers—PAPP‑A and free β‑hCG—often combined with nuchal translucency ultrasound to gauge risk of Down syndrome and trisomy 18. The penta‑marker is a later maternal serum screen measuring five biochemical markers (including AFP, hCG, uE3 and inhibin‑A) to assess risks for neural‑tube defects and chromosomal abnormalities. Both are screening, not diagnostic.

A maternal serum alpha‑fetoprotein (MSAFP) level of about 2.0 to 2.5 multiples of the median (MoM) or higher is considered elevated and raises concern for open neural tube defects such as spina bifida. When MSAFP is ≥2.5 MoM, clinicians usually pursue targeted fetal ultrasound and, if indicated, amniocentesis to measure amniotic fluid AFP and acetylcholinesterase for confirmation.

PAPP‑A (pregnancy‑associated plasma protein A) is reported as an absolute value and as MoM (multiple of median) for gestational age. In the first‑trimester double marker, low PAPP‑A MoM (commonly <0.4–0.5) with high free β‑hCG raises the calculated Down syndrome risk; the lab will show a combined risk number. This is a screening result, not diagnostic—discuss with your clinician to consider NIPT or diagnostic testing and placental monitoring.

The cost of a Non-Invasive Prenatal Test (NIPT) varies by country and provider: roughly $800–$2,000 in the United States, about £400–£900 for private testing in the UK (NHS may provide it free for high-risk pregnancies), and around ₹12,000–₹30,000 in India. Insurance coverage and test panels differ, so final out-of-pocket costs depend on location, lab, and selected screen.