Anyone understand the impact of gestational again on blood tests in the combined test?

[PenguinsDontEatPancakes]

I have been told I am high risk (1/100, which I realise means that there is a 99% chance all is fine) for Down's syndrome.

I don't have my full blood test results, but the NT measurement is within normal (2.4) and it is the bloods that are pushing up my risk.

However, I keep reading that the blood tests are very affected by gestational age. I am almost certain that the gestational age determined by my scan is at least 6 days further along than the actual gestational age (for various reasons which are really TMI).

I have an amnio booked for Thursday and plan to ask the consultant about my bloods in detail (neither of the mw's I spoke to knew anything about them), but in advance of that I wondered if people on here had any insight into what impact it would have had on my bloods if they were calculated based on being just over 13 weeks instead of just over 12.

Hey PenguinsDontEatPancakes,

I asked a Consultant about this a little bit when we had high risk results and the age was determined differently on our scan (but it was only 1 day).

Yes - the blood results are dependent on gestational age. We were told that a day wouldn't make much difference, but that they trust the age from the scan always.

However, 6 days is quite a bit and without know the TMI I'd trust that. However, it seems possible if the dates are off then it could lead to an increased risk assessment.

With your NT and 1/100 on the blood I'm confident you are likely ok. Fingers crossed for you.

Have you tried calling the Antenatal Results and Choices charity helpline? I had a 1:10 risk and found their advice and knowledge invaluable.

Do you know what MoM measurements your blood results gave? The MoM takes account of gestational age.

Hey again,

To answer your question from the other thread about my male perspective on the amnio/CVS procedure.

It is hard with childcare (we have a 2 year old girl) but we told a white lie and got my Mum to look after her. I'm glad we did as we had the NT scan at the FMC, got the 1:2 assessment and had the CVS immediately at the FMC. Because we got the bad news right away I was glad it was just the two of us, whereas the CVS results (good) take time. Given that you won't receive any results on the day there is less need maybe to be just the two of you.

As I understand it CVS is normally a bit more uncomfortable than amnio, taking a piece of placenta instead of amniotic fluid. However, the procedure was very quick, with the needly being in for less than a minute. It was quite uncomfortable for my gf, but nothing terrible at all. I focused on her to try and distract her from the discomfort.

Otherwise, from my male point of view it was just good that we were doing something. When there were things to do or research then I found that easier than just waiting.

You sound tough - I think your plan will be fine. My gf was uncomfortable after the CVS but for your arrangement your husband and DD can be with you after etc.

Not sure if any of that was useful! If you have more specific questions, then let me know!

Thanks for the comments.

The reason I'm pretty sure that their dates are wrong are twofold. Firstly, it would be borderline immaculate conception (we'd been staying with the in-laws. I apparently conceived on a date when we hadn't had sex for at least 10 days, possibly a fortnight). Also, they think I conceived on day 7 of my cycle, and I had really clear ovulation symptoms around day 12. Taken together, I'm fairly confident that their date is far less likely than mine. Scans apparently have a margin of error of 5-7 days anyway at this stage, so it's not outside clinical norms that they could have got it about 6 days or so wrong.

The always trusting the scan date thing is giving me the rage. I've already had a battle about it because my previous babies were both over a week late. Now that they've moved my due date, if this baby is a 'real' week late, they will think it is two weeks and want to induce me. (Which I realise I can refuse, but still...)

You were right what you said though about never changing anything. They won't re-scan, they won't discuss. One MW actually said to me "I'm afraid in the NHS it is 'computer says no'".

I am definitely going to try and get the consultant to tell me what changing the date would have done to the results though.

Arrt - Nope. I know nothing about the bloods. They haven't given the results to me yet. I am assuming someone will have them to hand tomorrow.

Thank you for the second post Dad (or perhaps I should shorten it to Tom). I've been doing a fair bit of online research too and keep finding dad's who have found it very traumatic to watch (I guess a bit like the way some men find it traumatic watching their partner in labour).

I think from my perspective I just want to close my eyes during the procedure and try and use my old natal hypnotherapy techniques to remove myself from the situation. But at the same time I don't want my DH to feel excluded. I might see whether, if all has gone smoothly, he can pop in when they check the heartbeat afterwards.

To be honest - he may feel excluded (I maybe would a bit), but in these situations you really need to prioritise. I think you're idea is a good middle ground.

I didn't find it distressing to watch, but rather found the whole situation distressing. I wanted to be there to support my girlfriend.

I'm sorry you're going through this. I just wanted to give you a small thing to consider. I underwent cvs in both my pregnancies for a 1:4 risk of a genetic condition. We wanted to keep everything a secret too. I had good news both times, but it was pointed out that if we had not received good news, we would then have had to explained to at least one person what was happening, in order to arrange childcare in order to undergo a TOP, or I would have had to be on my own.
If you can trust just one person now, and you have to undergo further tests, all you'll need to do is say 'help please' that may be easier than having to provide explanations at a very distressing time.
I hope you won't need this advice, and that everything works out for you.

Sunshine - I can totally understand that. The problem is the only people we really have who could look after DD2 (DD1 would be easy) are my parents, who are both religious and wouldn't understand TOP for any reason other than a condition incompatible with life. God knows what we will do if we get to that point, but at the moment I really don't want them to know.

Well, I went today. It was ok. I couldn't get any sense on the gestational age thing, but what was skewing my results was HCG of 4 times standard.

The procedure itself was fine. The worst bit was the needle coming out. Apparently the uterus (being a very strong muscle indeed) clamps down on it and doesn't want to let it go. That felt like the consultant was fighting with it. But other than that it was fine. Deep breaths and closed eyes.

Penguin I hope all goes well for you, I just wanted to share my experience. I had a Quadruple test done (in Northern Ireland that is all you get) I was so shocked when my risk of DS came back as 1:5 my age related risk was 1:540. it was the most difficult time of my life, I paid for a private scan and no soft markers were found but the Consultant said that 1/3 of babies with DS have a normal profile. HAd my NHS appointment and Amino booked for Wednesday, scan was again good and the Consultant recommended we pay privately for the Harmony. Had that done and am now day 4 in to the longest wait of my life. I was obsessively trying to make sense of my results and combed my notes, discovered to my horror that the hospital had entered my gestational age at time of blood test as 19 weeks and 6 days. I was only 15 weeks and 6 days at the time of blood test. COntacted the hospital the next day and got the results re-calculated and my risk came back as 1:1400, even better than my age related risk, so gestational age is important but am not sure how much difference 6 days will made. I am still anxious about my results. Hope we both have good outcomes x

Gosh, that is shocking Everything. 1:1,400 is about what I've had the last twice I think.

Results in early. All clear on the fast results.

That is great news Penguin congrats! x

Early results, and good ones! Congratulations