Down's test: US fine, but bloods indicate high risk

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We had our 12 week scan on Monday and although the US was fine, the bloods have given us a relatively high risk of DS.

This was a natural pregnancy (have read IVF can affect results) although I had a round of IVF in August last year (pre-chemo treatment I had in October). The chemo was only for 6 weeks and my oncologist was thrilled for me to fall pregnant: he says the only risk was that I wouldn't be able to get pregnant, and that there was no increased risk of abnormalities because of the chemo so that's not a factor (he's a worldclass expert so knows his stuff).

The US was fine - nuchal transparency of 2mm, strong heartbeat, correct growth. She didn't say she'd found a nasal bone, but she also didn't say that she couldn't so I'm not sure if she even looked.

The bloods have come back and given me a high risk of Down's. This is combined with my age and the US, but: I'm only 30 and my US was normal so neither of these would have affected the results...

So I'm confused.

Does this mean that if the baby does have DS then it's less affected than if something was showing on the US? How can the two show such different things?

We're not having further testing since we're Christians and would not abort but we'd like to be prepared to give a DS baby the best possible start.

Or, thinking about it, does having weird bloods indicate some other problem (not DS)??

Bump - anyone?

I had a high risk result that was attributed to blood test results. My NT was 2.6mm which is high but not alarmingly so, my bHCG was a bit high at 1.65 MoM (I'd had fertility drugs so wasn't that surprised) but my papp-a was very low at 0.39 MoM and it is the papp-a that made the biggest contribution to my risk of 1:15, aged 35. The scan was otherwise fine, no soft markers were found.

I did have a CVS, and we had the all clear, and my little boy is nearly 16 months old now.

Often, these results are just variations on the norm, and don't indicate anything else. Sometimes bHCG can be high because of fertility drugs, a lost twin, etc., but I don't think it indicates any other issues (but as my bHCG wasn't really really high I didn't really research it). Low papp-a can rarely be an indicator of a poorly performing placenta which in turn can lead to a small baby or IUGR, and possibly an early delivery. However, despite my low papp-a my son was born by planned c-section (unrelated reason) at 39 weeks weighing 8lb 6oz. So in our case, it was just that my results were a variant on the norm.

What is your actual risk in 1:x?

You will get more information at your 20 week scan, although a scan alone only identifies I believe about 50% of down syndrome pregnancies. So you may not be much wiser following that!

I hope that helps. Good luck with your pregnancy.

Thanks - that's helpful.

The actual risk is only 1:90 which I realise is actually still very low percentage wise. It was just a bit of a shock getting a phone call from the midwife, particularly when my first pregnancy was remarkably uneventful!!

I'm a bit more realistic about it today. 1.1% chance is tiny, and it's only about 0.4% higher than a 'low risk' pregnancy, so I'm trying not to worry: the risk of a 'normal' second tri miscarriage is pretty much that and I'm not worried about that...

Time will tell I guess, and I'm just focussing on the fact that the baby looked strong and healthy on the scan.

Mmmh, I do wish they would give the results in % terms, as it is much easier to understand rationally! If they'd said to me 7% risk, it would have resulted in a lot less knicker twisting than 1:15 did!

I agree - it sounds so so different.

I called the ARC about my situation and that was the first thing she said: think about it as a percentage. And wow - that was a real eye opener.

7% is very very small. If I had a 93% chance of winning the lottery, I'd put quite a lot of money on it I think...!

1.1% is pretty good, they may send you for extra scans to check for other soft markers which may give you a hint

Just an update.

After thinking about it, we went to the Fetal Medicine Centre on Harley Street for a repeat 12-week scan. If there was a problem, I'd rather know now and I was going mad with not understanding how the scan and bloods didn't match.

They were amazing. They did a detailed scan which looked at 6 (I think) markers for DS, all of which were normal (interestingly, the nuchal fold measured 1.5mm this time, 0.5mm smaller than on the NHS scan - not sure if it's normal for it to change or if it means one of the measurements is off: he repeated it lots though so we're pretty confident in the 1.5mm). They also did bloods, which were 'bad' again (think HCG was 3.4MoM ish and the other one was 0.5MoM ish).

However my overall risk came back as 1:2500 (compared to 1:90 based on just nuchal fold and bloods).

The doctor explained that a woman's bloods can be naturally 'bad' and that it doesn't signify anything in particular in relation to the baby or the pregnancy: it's just how her body reacts to the baby. So if you're only looking at nuchal fold and bloods (as in the NHS combined test), having 'bad' bloods can make a huge difference to the overall risk even though it could just be normal for you. Taking all the other markers into account gives a much more accurate view. He also said that having 'bad' bloods doesn't mean anything in particular in relation to the pregnancy and other risks/problems: it's just one of those things and nothing to worry about unless there are other signs (or the bloods were much worse).

I asked how my risk with DD 30 months ago could have been so much less (around 1:3000 after the combined test) and he reckoned that my bloods would still have been bad then but my risk was less due to me being younger and probably having an even smaller nuchal fold.

So we've already decided that if we have a third in a few years (!) we won't bother with the NHS combined test: my bloods are likely to still be 'bad' and combined with an increased risk due to my advanced age (ha!), the overall risk will come out higher than this around but give us no real indication of the health of the baby.

Sorry for the essay, but I hope that this can help reassure other women in a similar situation. The combined test is good and useful, but it's not the most accurate testing there is, and if you can afford it, a private scan like this seems to be a really sensible first step before opting for an amnio and the associated (albeit minimal) risks.

Phew.

Delighted to hear your good news, that's really reassuring isn't it?

Hope the rest of your pregnancy is peaceful and calm . Nice of you to update.

Thanks :) Yes - I left the clinic feeling that I could really start to enjoy the pregnancy and 'bond' with Bump: for a few days before I hadn't really dared to, just in case something was horribly wrong.