12wk combined screening 1 in 2 risk

[Geriatrixia]

Posting this in case anyone else has had a similar experience as my head is spinning right now.

I’m 14 weeks with our rainbow baby after stillborn twins in 2022, and I got a call from fetal medicine yesterday saying our combined screening came back HIGH for Patau’s and Edward’s, despite the fact the nuchal measurement itself was normal.

Normally the next step is NIPT but we already went privately at 10 weeks and everything came back low risk, less than 10,000 which is obviously a HUGE difference.

The fetal medicine consultant is on holiday this week and will call me next week to arrange further scans and testing. We’re trying to take comfort from the NIPT but obviously 1 in 2 is HIGH.

I stupidly started googling and apparently when the combined test is so high it can mean the NIPT is less reliable?

Not sure how we’re going to get through the next few days.

I live abroad and here they only offer NIPT from 12 weeks. When I was asked why Inwas told so that the level of DS’ DNA was higher in my blood to allow for a more accurate result. Did your NIPT result state the refraction percentage? If yes is it over 4%? If it’s over 4% it means there was enough fetal DNA fragments for analyses.

I am not sure where you have found on google that combined testing is more accurate than NIPT. Here they don’t even do combined testing you only get NIPT as it’s considered the gold standard. Measuring your serum levels of certain hormones can be an indication of chromosomal abnormality but not definitive. Normally the next step after high risk for combined is NIPT so I personally would look at the NIPT results. But I understand that’s easier said than done.

Thank you for your reply- our results said they got 5% so no concerns in that regard.

I’m 45 which will obviously bump up the probability with the combined screening, and my PAPP A was low at 0.17, but the NT was only 1.8 which feels like a real positive.

I think I’d feel more confident with the NIPT if fetal medicine weren’t still saying we need a more detailed anatomy scan and possibly more testing, but I’m assuming/hoping that the combination of my age and the loss
of our twins means they’re taking absolutely no chances.

Your age would definitely push up the result on your test results. Your NT was really good and your NIPT had enough fragmented DNA for analysis so those results are accurate. The NIPT is a very accurate test so I would put stock into them and try not panic till you speak to FM next week. Dif you provide the hospital with a copy of your NIPT results when you did it privately? It could be that FM wants to speak to you as all they have on file is your combined results.

First of all, I'm so sorry for the loss of your twins. My heart goes out to you ❤️

Combined screening is less accurate than NIPT but cheaper for the NHS to do, hence it's the normal practice. When combined comes high, people are either recommended NIPT or amnio. Lots of people will choose NIPT and if but comes back low, leave it at there. If NIPT comes back high, they to amnio.
In your case, I'd be trusting NIPT result a lot more than the combined screening result.
Like the previous poster said, your age will have had an impact on the combined.

See if you can speak about all if this to someone at hospital, take your NIPT result. They should reassure you ❤️
All the best

Sorry you’re going through this. With that level of risk, it is definitely really important to see and talk with Fetal Medicine and have a detailed scan. Although the low chance NIPT is really reassuring in terms of Down syndrome, T13 and T18, it is still not 100% accurate on those, and it doesn’t give useful information on rarer abnormalities, or on things like triploidy (for most NIPT types anyway) which can drive low serum results. I would be thinking about having a CVS or amnio anyway but of course it depends what you see on scan and your overall thoughts. Best of luck and fingers crossed it turns out to be a false alarm.

I wanted to update and thank everyone again for their replies.

we had our detailed scan with fetal medicine today: the consultant was great, spoke to us all the way through explaining what she was seeing - essentially everything was textbook, and although we have the option for amniocentesis, there’s nothing on the scan today that would make her urge us to get it done.

as I suspected, my age (45) and low PAPP-A is why I have such a high combined screening, but the low NIPT with the detailed scan today is looking a lot more positive. Fetal medicine will do our anomaly scan in three weeks time, which makes me feel better too.

Hi I wondered if there was any update on this? I have had a similar situation!

What a worry, I hope you get answers soon, and that our story helps calm you a little. Our baby boy was born on New Year’s Day, induced two weeks early because he was 8lb 8oz! A little jaundice but otherwise absolutely fine.

Fetal medicine gave us detailed scans around 16, 18 and 20 weeks and confirmed everything was looking good. Because this was a pregnancy after loss, we ended up with fortnightly scans, at first with fetal medicine and then alternating between them and a regular sonographer. We navigated a few extra potential issues (placenta previa risk that resolved itself as everything grew, then he was flagged three separate times for gestational diabetes because he was literally off the chart - no GD, just a massive baby) but everything was fine.