What could cause very high hCG at 12 weeks?

[BettyBi0]

Does anyone know what might cause an unusually high free beta hCG at 12 weeks?

I had my NHS nuchal scan at 12+6 and came back as 1:44 risk of Down's due to having an hCG of 4.56 MoM. The NT was 2.6mm so not massive and the other PAPP A was normal.

I've since had my Harmony bloods back with a 1:10000 risk of the 3 main trisomies but I just can't relax. Why on earth is my hCG so so so high?

The Dr said that it could indicate other chromosomal issues but as my NT was in the normal range I would not be a candidate for full karyotyping via CVS or amnio but I was welcome to have a CVS to confirm no Down's.

In case it's relevant I'm 37, had ICSI and a single frozen embryo transfer. I had a big bleed at 5+3 and was diagnosed with a subchorionic hematoma. Continued to spot brown blood for first 6-9 weeks but nothing since and reassurance scans show the hematoma is absorbing.

I had 5.something (can't remember now!) bHCG with my DC4 who is now 19 months. Combined with a borderline NT, she was a 1 in 5 for T21. We also had a "clear" Harmony - false negatives are a lot less likely than false positives. We did no further tests as I did not want the risk.

This was all done through the FMC and they were not worried at all, they never mentioned other chromosomal issues and I never came across any significant mention of that in my research either unless things have changed in two years. They said it was almost certainly due to the bleeding I had in the first trimester that was the cause, sounds like it's the case for you too. I did take baby aspirin as I'd read research that suggested it might be beneficial; my consultant saw no problem with it.

DC4 was born a normal size at 36+6 - normal for me as I never get close to 40 weeks - and is completely typical with no medical issues whatsoever. The pregnancy was pretty much uneventful.

Good luck and congratulations!

Thank you! I'm so glad everything worked out well for you and it gives me hope that I can do the same.

I'm just going to hope that the early bleed is what has twisted the numbers and that all is well with the baby

We're you given your bHCG and PAPP A result because of your initial DS risk score?
I keep reading about mums getting these results and I haven't been given them in this pregnancy or my last, only my DS risk

'Were' not we're

I think they use the hcg and Papp a to calculate the risk score. So you have your background score by age, then the adjusted score based on your personal bloods and by measurement

Update from me... Had another chat with the speciality midwife and she has discharged me back to the standard maternity team. If my hcg had been higher then I would have been offered serial brain scans before 20 weeks apparently. But because everything looked structurally normal for stage, and NT of 2.6 was in their normal range, they have told me to wait for the standard 20 week scan.

That's great news bettyBio you must be thrilled :-)

@BettyBi0 your bHCg numbers and sub hematoma is similar to mine. I am wondering what was your outcome with baby ?