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PAPP-A (first trimester screening)

Fertility and pregnancy · also printed as PAPP-A, PAPP A, Pregnancy associated plasma protein A, PAPP-A MoM, Combined screening PAPP-A

Typical UK adult range0.4 MoM and above

Around 1.0 MoM is average; below 0.4 MoM is flagged by many units.

What this test measures

PAPP-A is a placental protein measured at 11 to 14 weeks as part of combined screening. It is reported as a multiple of the median (MoM) for the gestation.

Why doctors request it

Part of the combined screening test for Down's, Edwards' and Patau's syndromes, and a low value is also noted for placental function.

What commonly pushes it up

Nothing in particular

What commonly pushes it down

Some chromosomal conditions in the baby
Smaller placental function, which prompts extra growth scans in some units
Wrong dating

Everyday reasons for a value outside the range

It is only meaningful as a MoM for the exact gestation
The screening result is a combined probability calculated by the screening lab, not this number alone

About the sample

Reported by the antenatal screening programme.

Written by a UK consultant physician. Typical UK adult reference ranges; your laboratory's own printed range takes precedence.

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This is an educational summary of results you uploaded. It is not medical advice, a diagnosis or a treatment plan, and it does not replace the doctor who requested the test. If you are worried, or a result is marked outside range, discuss it with your doctor. Written and reviewed by a UK consultant physician. Reference ranges vary between laboratories.