NT testing and HCG

[Itscurtainsforyou]

Hi there - I'm 9 weeks pregnant and due to have my NT testing done in a few weeks (all being well...). I've been reading up on the blood test, which looks for high levels of HCG (for downs) and low levels of papp-a (for T13 and T18).

My concern is that I'm currently having high doses of HCG twice a week under the recurrent miscarriage clinic and will continue to have these until 16 weeks. Will the high doses have an impact on the results? My head is telling me that they must do, but I can't find out anything on the web.

Also if I'm considered high risk, how long does it take to find out for sure through amnio/CVS/harmony?

Many thanks

You're taking additional hcg? Is that right? (Sorry my heads not reading very well atm)

If so I imagine they will be able to adjust your blood levels when they get your results.

It may well mask some issues looking solely on hormone levels. Are you under a consultant who is giving you the additional hcg? Could you ask them?

Personally I'd be tempted to request or pay privately for a harmony/nifty test if the hcg is likely to skew your 12 week blood results.

Sorry didn't answer you question.

Amnio and cvs can fast track results for main 3 trisomies so between 3-5 days. Harmony results take about 2 weeks afaik.

Thanks! Yes that's right, regular hcg injections. I was going to ask the consultant but I don't see her for a few weeks now (at the point of the test) so was trying to gather info so I can discuss it with my OH before I go...
I guessing ultimately if the hcg levels detect downs and the Papp-a level detect likelihood of t13 & t18 then even if the hcg is skewed the test should still detect the info I need (given that t13 & and t18 are less compatible with life than t21 - if that makes sense?)

As far as I know it's not just the papp a that indicates t13 and t18 but low papp a combined with low hcg. T21 bloods generally are low papp a with high hcg.

What I'm saying is the hcg could artificially inflate your hcg levels masking a low papp a combined with a low hcg.

I would be very surprised if they couldn't do something to take the hcg injections into account or offer a different test.

I know bloods aren't the only factor in the combined screening but I came back with dodgy bloods but a perfect nt measurement. It wasn't further investigated until soft marker were found at my anomaly scan and T18 was diagnosed after an amnio.

No ones fault at all but in your position I would call the consultant and ask how your combined screening will be adjusted or what other tests they will do.

That's really interesting, thank you. And really sorry that you have first hand experience of this.