Low fetal DNA - NIPT test

[CakeSchmake]

Has anyone else experienced this?

Had bloods taken for a private NIPT at 10+5 and found out today they will need to be redrawn due to low fetal DNA.

I'm feeling really anxious now. Googling (stupid, I know!) tells me that only two thirds of repeat bloods are successful, and also that low fetal DNA is more commonly found in cases of chromosomal abnormality. I know that BMI can have an effect, so hoping that it's my BMI of 27 which has led to this rather than problems with the baby.

Has anyone else ever had this happen? Would love to hear your experiences if so.

Hi, not an expert but sometimes it's just too early for enough fetal DNA. I wouldn't think anything is wrong. When i did my test i prepared for this to happen just in case.
You should wait until 12 weeks and get your bloods done again.
Good luck!

The same thing happened to me. I first tested about 10 ish weeks and had a no result. I was advised to re test about 4 week later and it was fine. I was really stressed too and thinking it meant something was wrong. My bmi is fine so I have no idea why mine was low.

Thanks so much for your replies - they've really helped calm me down. My redraw will be at 12+1, so hopefully that will work. Glad to hear everything worked out ok for you LillyLeaf.

Same thing happened to me - only got a result 4th time (at around 14 weeks!) and everything was totally fine

Good luck for your retest!

I had 3 fail with low fetal dna - harmony tests, I have higher bmi so believe this was the reason.
Strangely I did an Iona test which is similar the same day as my 3rd harmony which works with a lower fetal factor - and came back saying mine was 10% - so no idea why the last harmony didn’t work.

Hi there, I'm a genetic counsellor and we don't really know why this happens a lot of the time. Some women just seem to have a lower fetal fraction (the amount of genetic material from the baby) in their blood stream than others. The amount usually continues to increase through pregnancy but rarely it continues to be low. To my knowledge it doesn't mean anything is wrong. I hope it works for you next time... To my knowledge it's rare that it repeatedly fails but i am basing this on the test that's available on the NHS.

Thanks everyone for your responses. My redraw failed too. I'm feeling really worried still. I actually wish I could have CVS to find out for certain if there are issues, but the NHS won't offer it as my screening was low-risk and I'm struggling to find a reputable private specialist in my city. Also DH thinks I'm insane. I know I'm letting my anxiety get the better of me, but I've read several studies now showing links between low fetal fraction and fetal abnormalities.

Can they offer you the SAFE test? I failed twice for harmony and safe was clear.

Hello, I had two failed harmony tests due to low DNA fetal fraction. I read everything about it, read all the blogs etc and I was very worried that something was wrong. At the end I decided to try a different test, the prenatalsafe in a clinic in London and the results came back negative! I strongly advise to do this test if the problem was the low DNA fetal fraction

I also had 2 failed Harmony tests, it caused me so much stress and anxiety. I wish I'd never done it. We were offered another redraw at 20wks but declined and did the NHS screening. It came back extremely low risk (especially considering my age - 42) and all scans have been perfect. I was happy with that.

Sorry you’re feeling so anxious because of this! Some good advice/info already here but just wondered whether you’ve been referred to an obstetrician for discussion? It’s helpful to talk things through with a specialist. As others have suggested you could consider a retest with a different type of NIPT - I’m not UK based so I don’t know the companies sorry - and I also don’t know the NHS referral criteria but seems like you deserve an appointment at least!

I'm really sorry to hear this. I would consider a different company if you're financially able to. I believe another factor can be how long the samples are stored for. I can recommend the west Midlands genetics lab (accessed through the antenatal screening coordinator at Birmingham women's) depending where you're based. As others have said it would also be important to let your midwife know how you're feeling if you haven't already.

Update: I had a third NIPT at 17 weeks. It worked and came back low risk.

I also had my anomaly scan with a doctor at the fetal medicine unit, who looked thoroughly for any issues but had no concerns.

They did offer me an amnio too. I've been seriously considering it, but finding it hard to justify the risk of miscarriage after the low risk NIPT, clear anomaly scan, and the fact that my NHS screening came back 1 in 100,000 risk for Edwards and Pataus.

It's just that the amnio is the only definite answer and all the screening tests are only 90-97% accurate!

I suppose I'm looking for some reassurance that after all these clear screenings I can stop worrying?!?

OP, that's great your results have been clear. Why would you risk an amnio when there is no clinical indication that you need one? Do you usually struggle with anxiety or has it been since becoming pregnant?

Hi Op, I had a similar issue. First draw at 13 weeks had insufficient dna. Second at 15 weeks worked and I was told low risk. I’ve also got a high BMI.

I decided to rely on the harmony test result. In my view, there’s no need to do any more tests. You most likely had the first two draws too early! 10 and 12 weeks is very early really. 17 weeks is a good gestation to check for anomalies and you’ve had a thorough scan too which came back fine.