12 wk combined screening – just for Downs, or Edwards and Patau too?

[firsttime4everything]

I've just had my results back from the combined screening (bloods and NT) and they're low risk for Downs, which I'm obviously really happy about.

However I was under the impression – mainly from reading other MN threads I think – that this screening can also give your risk for Edwards and Patau syndrome.

No mention of these on my letter, so I rang the midwife helpline at the hospital and was told these were only looked for at the 20 week scan, and the 12 week combined screening was for Downs only.

Is that normal? Is this just one of those things were different hospitals do it differently and you have to lump it?

I know both Edwards and Patau are rare, but I still feel bothered that maybe something could have been checked out sooner than it's going to be. (Which does seem relevant, given that a termination would I guess be recommended if Edwards or Patau were eventually confirmed, and once you get to 20 weeks that's a different prospect from earlier).

In my first pregnancy I was given separate risk factors for Downs, Edwards and Pataus. In my second pregnancy (different county) it was just Downs, so I assumed that they don't test for Edwards and Pataus at this particular Trust. I also assumed that if my bloods of nuchal measurement had been outside of the normal range, further testing could have been done, but there was evidently no need.

The combined bloods give you a risk for ds. They will also look at hormone levels for T13 and T18 but will only report if your risk is more than 1:100.

Have you been given a breakdown of your blood hormone levels? A very low Papp a combined with a very low hcg (both less than 1 mom) are pointers for T13 and T18. Low Papp a with a high hcg will give you a higher risk for T21.

If you're worried call your midwife.

Saying that my bloods came back as a less than 1:100 chance of chromosomal defectso nothing was reported to me. We found soft markers at the 20 weeks scan.

However, I did have a very low Papp a level.

The baseline for edwards and Patau are around 1:3000 and 1:500 so very low risks.

There's regional variation which I didn't realise. My hospital does all 3. I think though that soft markers for Edwards and Pataus are quite obvious at 12 weeks.

Soft markers for T13 and T18 are not clear at the 12 week scan.

Our baby had some quite 'obvious' defects that weren't picked up until the 20 week scan, then some were only picked up by kings specialist scanning. Not the fault of the hospital at all.

Honestly early on your blood tests are going to be the main pointer. Ask to look at the results, if both Papp a and hcg are low then ask someone to look at them.

The problem we have in our trust is that you only consent to the risk of Down's syndrome being reported to you.

I know it's is a worry once you have it in your head but please try not to, it is highly unlikely that you will have a baby with a serious or incompatible with life defect.

Oops, sorry to spread misinformation.

Sorry, I hope that didn't sound snappy.

Having been through it all recently I've learnt a lot about it (edwards anyway although Patau seems to show itself almost identically in blood work and soft markers) very quickly :)

Honestly though, I don't mean to sound patronising but unless someone has told you that you are at a higher risk then please don't spend your time worrying. It is such a low baseline risk it really isn't worth worrying about.

Thank you all for your help on this. Since posting I've come to accept that it's obviously just different in different places. It's not that I'm especially worried that these things could be a problem – more just getting my head round not being given some information I was expecting!

Having said that about differences in different places, it does appear it's now been recommended that everyone screens for all three at the same time, see:
www.screening.nhs.uk/t18andt13

But seemingly it will take some time for this to actually be implemented...

I hope they do screen for them all soon. I may save some heartache later on when problems start getting picked up.

I guess the reason they don't do it routinely is that they are so unusual.

My understanding is that they do looks at the bloods in relation to all trisomies and will report to you if your results give a higher than 1:100 risk (so classed as high risk)