I just had an interview with a prospective client and she mentioned that she had a low reading on the PAPP-A test.  Since this is a relatively new test, none of her providers seemed to have any idea what that really meant and are proposing a late 3rd trimester ultrasound.  She is hoping to avoid the u/s, especially since she has a good understanding of the slippery slope that could ensue as a result. 

I feel comfortable with discussing the pros and cons of testing, informed consent, etc., but this test specifically, I have no knowledge of.   Would you please share your thoughts and any info you may have?  How specific is it?  What does a low reading really mean?  What would an ultrasound tell them?

Thanks!

So I ran a search on Yahoo and turned up this article and on Medline Plus, Pub Med's site for the public, and turned up this one. The gist is that the test screens for Down's syndrome, and a low reading means a higher risk of having it. Keep in mind that screening tests are NOT diagnostic. Most positive screening tests turn out to be false positives. Screening tests are only intended to separate out a segment of the population for further testing. If your client wants to pursue this--and I say "if" because if she would take no action if she found out that the fetus had Down's syndrome, she may not wish to pursue further testing --she will want to find out what her testing options are, how accurate their results are in ruling in or ruling out Downs syndrome, and what their risks are.

I'm still scratching my head over your saying that her care providers ordered a test without knowing how to interpret its results, not to mention that they could have obtained this information from the internet with a few clicks of a mouse or, if they wanted to do it the old fashioned way, a phone call to more expert colleagues. If I were her, I would seek out a genetic counselor or some expert of this type to discuss the test's implications and her options because if what you say is true, she is unlikely to get what she needs to make an informed choice from them.

-- Henci