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DS risk much higher with 2nd pregnancy - anyone else?

(30 Posts)
KittyTN Sun 02-Aug-09 15:12:29

I have a gorgeous ds1 aged 19 months who had a private combined test risk of 12,444. I've just had the result back for my current pregnancy done via the NHS this time. The risk was quoted as 1 in 850 - unfortunately the results were generated based on a wrong ethnic origin. I phoned the screening service on Friday and got a recalculated risk verbally of 1 in 1700. Certainly not nearly as worrying as some of OPs on similar threads. My risk this time is high due to high bHCG and low PAPP-A, NT thickness was good. I am worried my results may be statistically low risk at population level but in fact represent a high risk to me as an individual - apparently protein levels in any given woman tend to follow in subsequent pregnancies. Has anyone else had vastly different risks quoted for different pregnancies? Any other thoughts?

angel1976 Sun 02-Aug-09 20:28:34

Hi kittyTN, I won't say don't worry as it's impossible to do anything but worry in a situation like yours. How old are you? 1 in 1700 is extremely good! Based on age alone, a girl aged 15-19 has 1 in 1250 risk of having a baby with DS, your figure is even better than that! My first pregnancy, I had a 1 in 63 risk of having a baby with DS (based on nuchal alone) and my DS is perfectly healthy. This pregnancy, I had the combined test and has a risk of 1 in 21,000 of having a baby with DS but baby is due in November so I am not out of the woods yet.

KittyTN Sun 02-Aug-09 22:21:23

Hi Angel - thanks for replying. I will have recently turned 33 when this new baby is born. I know that 1 in 1700 doesnt sound bad. It's the vast difference between my two pregnancies that most concerns me. Thank goodness for you that everything turned out well with your ds - you must have been so worried. Did you have a CVS/amnio? Your current DS risk sounds incredibly good and presumably no soft signs at the anomaly scan. Good luck!

angel1976 Sun 02-Aug-09 22:35:20

I had two CVS with DS... The first one failed as they took too much of my cells instead of baby's so they redid it 5 days later! The one good thing that came out of that was I thought we have had our share of bad luck, surely it's time things work out for us and it did! grin You know what though? After the first pregnancy and the traumas associated with it (my blood also showed elevated level of PAPP-A (this we found out only because we consented to having bloods taken for academic purposes, and it apparently could mean fetal growth issues!), I don't take anything for granted anymore. I just hope that after bring through the mill with DS1 during the pregnancy, someone's decided to give us a break with our second! I will have just turned 33 when DS2 is born (in Nov) as well. Just imagine how things would have looked for me if my risks for both pregnancies were reversed... 1 in 21,000 to 1 in 63 (definitely a million times worse than yours!). Good luck! I am sure everything is fine.

Millarkie Sun 02-Aug-09 22:51:11

Where are you getting the idea that the levels are similar in subsequent pregnancies? The chemical markers measured are produced by the placenta not the mum, different pregnancy - different placenta.

Millarkie Sun 02-Aug-09 22:53:50

The difference in your age at last pregnancy and your age now must also be taken into account - it is incredible how the risk calculated by age alone increases with each year.

KittyTN Sun 02-Aug-09 23:35:13

Hi Millarkie. Women who have a false positive result have a statistical adjustment to their risk calculation in subsequent pregnancies to take account of the tendency for protein levels to follow a trend. I cant remeber which of the numerous sites I read mentioned this. It may have been the wolfson institute site or the alpha model details. I can look at my search histories and try to find it if you're interested.

KittyTN Sun 02-Aug-09 23:39:14

Angel - 2xCVS, what a nightmare! You 'deserve' your good score this time!

Millarkie Mon 03-Aug-09 18:38:37

KittyTN - I would be interested if you can find where you read it, thanks.

KittyTN Wed 05-Aug-09 11:01:12

Hi Millarkie - sorry for slow reply, as you can imagine I'm rather preoccupied at the moment. There are several sources of info but this one is particularly accessible - 'Taking account of screening in a previous pregnancy'.

Are you dealing with a similar situation at the moment?

It's a shame no MNers have responded to say that they had vastly different combined test scores between pregnancies with a good outcome. I'll keep checking in the hope that there are some happy stories out there!

PortAndLemon Wed 05-Aug-09 11:17:06

Would they tell you what your odds would be if you had the same results but were two years younger (i.e. a more accurate comparison of bHCG and PAPP-A levels)? Another thing to bear in mind is that the private test last time may have taken more factors into account than the NHS test did this time (e.g. measurements of nasal bone and blood flow through the heart) which would enable them to give you a lower-risk result two years ago than you would have got from nuchal thickness and blood tests combined.

If you're still within the nuchal testing window, could you return to the same place you went last time for another private test? Then you'd be comparing more directly (and there would be someone qualified and experienced to talk through the results and your concerns about individual protein levels with you).

PortAndLemon Wed 05-Aug-09 11:21:55

Have checked and, for example, the FMC base their Down's syndrome odds on

# Nuchal translucency
# Presence or absence of the fetal nasal bone
# Fetal heart rate
# Blood flow through the tricuspid valve of the fetal heart
# Blood flow through the ductus venosus in the fetal liver
# Presence or absence of any physical abnormalities
# Levels of free ß-hCG and PAPP-A

whereas I'm reasonably sure that in my area at least the NHS odds are just based on nuchal translucency and ß-hCG and PAPP-A levels. That would enable the FMC to potentially give much lower odds for a specific pregnancy than the NHS could provide.

(What I'm getting at, in case I'm just rambling too much, is that if all of those factors were considered in your 1 in 12,444 result last time, then potentially if they were all considered this time your odds would be much closer to 1 in 12,444 than 1 in 1700)

KittyTN Wed 05-Aug-09 12:27:17

Hi PaL
That's a really lovely thought! The NHS result only included NT and bHCG, PAPP-A levels. The nasal bone was present but not included in score. NHS took so long to send results through that I'm too late to repeat. FMC have said they would only offer 2nd trimester screening in the absence of a combined test.

I've checked my previous private scan report (done at our local Nuffield by one of the NHS ultrasonographers moonlighting!) and unfortunately it appears to only factor in bloods and NT. Would def consider FMC in next pregnancy. I've booked for a detailed anomaly scan at FMC at 21/40 which will hopefully be reassurring.

Obviously my background risk has gone up abit in the last 2 years but the larger factor is that both bloods are worse this time. They were bHCG 1.7 MoM, PAPP-A 1.5 MoM. This time bHCG 2.3 MoM, PAPP-A 0.91

Have you used the FMC in the past? Any feedback?

PortAndLemon Wed 05-Aug-09 12:57:29

Only for viability scan, and they were lovely -- I was having some bleeding on the Friday of a Bank Holiday weekend, called them and even though they were fully booked they rejigged to get me a same day appointment as otherwise I'd have had to wait until the Tuesday. Everyone very lovely -- professional yet reassuring -- and the scanning facilities themselves were top-notch.

I've since heard very good things about them for nuchal scanning as well, and I think they take the bloods first and do the analysis immediately so that the results are available to combine with the scan measurements the same day with no hanging around (not sure whether that's normal for private scans, but AFAICS definitely not normal for NHS scans). If we do have a third child (still undecided, but if we did then I'd be at least 38) then I've said I would have my nuchal scan done there rather than rely on the NHS one.

Just vaguely thinking through (given that your main concern is the change in ß-hCG and PAPP-A levels between the two pregnancies rather than your headlne risk level), are you the same weight now that you were with your first pregnancy? I think PAPP-A levels are affected by maternal weight (although I don't know in which direction). And how sure are you that the dates they have you on are correct? If you are slightly less pregnant than they calculated then you'd get relatively higher ß-hCG and relatively lower PAPP-A values.

eidsvold Wed 05-Aug-09 13:10:46

Your chance of having a child with down syndrome increases with maternal age. With each of my three pregnancies - just based on pure chart of general info - the chance became greater the older I was. I was 33 turning 34 when I had dd1, 36 when I had dd2 and I was 38 when I had dd3. Dd1 my chance turned out to be roughly 1 in 5 - although we were told if she were born without down syndrome it would be very very rare - she displayed a hard marker at 20 week scan. With dd2 my chance was increased because of age and because of the fact I already had a child with down syndrome. Compared with the general population I again had a greater chance.

With dd3 we had a nuchal translucency screening given that it can indicate far more than down syndrome - and fwiw - far more serious and life limiting conditions than down syndrome. In fact we had our NTS because we learned of a congenital heart condition my dh had that was not diagnosed until after dd2 was born. My three children have a greater chance of being born with my husband's heart defect than they did of being born with down syndrome.

A raised nuchal measurement can indicate that a heart defect is present - so down syndrome is only one thing that can be indicated. With dd3 - my general chance was 1 in 52. Post NTS it was 1 in 962 - about the same as a woman 10 years younger than me.

DS was not something we were overly concerned about. In fact I was more worried about dd1's heart defect than I was about the fact that she had down syndrome.

I do find it odd that you would accept that personally a ratio of 1 in 1700 is high risk.

PortAndLemon Wed 05-Aug-09 13:26:21

I think OP's issue, eidsvold, is that the 1 in 1700 is based on "an average woman of this age and ethnicity with this NF measurement and these ß-hCG and PAPP-A levels", whereas the research she has read suggests that the risk level, if calculated for "a woman of this age and ethnicity with this NF measurement and these ß-hCG and PAPP-A levels, who had substantially lower ß-hCG and substantially higher PAPP-A levels at the same point in her previous pregnancy" would be higher than 1:1700.

Therefore (given she did have substantially lower ß-hCG and substantially higher PAPP-A levels in her previous pregnancy) she is concerned that her actual personal risk level is probably higher than 1:1700, possibly (although she doesn't know) quite a lot higher, and that is what she is concerned about.

I'm probably not explaining that very well.

angel1976 Wed 05-Aug-09 14:04:21

KittyTN - I had a 32-week scan at the FMC with my first pregnancy. Because of all the 'problems' we had with our first pregnancy, I wasn't convinced even after a 28-week scan with the NHS showed that DS had no growth issues. They took almost an hour to do the scan and was very thoroughly in measuring everything. They even switched the machine to 4D for a bit so I could see DS's face! They are really, really lovely there and I am sure you will feel very re-assured there.

P.S. The nasal bone present is a very good sign. Before I had my CVS, they told me they could see the nasal bone and that was a great sign but they weren't allowed to adjust my risk.

KittyTN Wed 05-Aug-09 15:32:20

Great to hear such positive feedback about FMC. I'm really hoping that the 21/40 scan will be encouraging. I feel as though this pregnancy is on hold until then. Given that I'm not classed as high risk, I don't really have any other options. V good news about nasal bone - I wonder how predictive that is?

linspins Wed 05-Aug-09 20:03:54

My odds with this pregnancy were 1:230 after a nuchal scan (low reading) and combined bloods (where one reading was a weeny bit high and the other a weeny bit low). The odds took my age into account too (37).
These odds are only just in the high risk catagory, cut off was 1:250. But we have previous history with two babies with severe heart defects and chromosomal abnormalities (different ones to each other).
So we were sent to the Harris Birthright centre at Kings hosp, for more scans and with a CVS in mind.
This is where prof Nicolaides works/teaches some of the time, and they are very good.
After detailed scanning, checking nasal bone, blood flow, heart etc, and more blood tests which were processed immediately, my odds went down to 1:1732 for downs and 1:21000 for the other two.

So it can change quite dramatically after more scans. We didn't have the CVS.

I have never heard that your readings are personal to you and follow a trend? Interesting stuff if true.

Any way, GOOD LUCK!

angel1976 Wed 05-Aug-09 20:24:44

KittyTN - Don't quote me on this but I read somewhere (if I remember the stats correctly) that 70% of babies with DS DON'T have a nasal bone while only 20% or 30% of babies with no chromosonal defects don't have one.

If you are really interested in the details of the nuchal scan, check out this online course from the FMC presented by Prof Nicolaides. It might be a bit hard to understand in parts but it is very good at telling you all about the risks and how each marker matters.

peanut08 Wed 05-Aug-09 20:36:48

Hi have been reading this thread with interest as have recently been trying to make sense of my own results for all 3 pegnancies (all in the past but interesting as have been very high risk and very low risk) this page shows 73% of babies with DS had no nasal bone at 12 weeks. There may also be some other useful info haven't read it all myself yet.

KittyTN Fri 07-Aug-09 16:33:26

Hi everyone thanks for replying
Linspins - Prof Nicolaides runs the FMC too (private) we may be lucky enough to get him for our 21/40 scan. Are you still pregnant with number 3? If so, good luck to you too!

I did the online course yesterday. Peanut's Lancet article was interesting - I wonder if they have gone on to show that absence of nasal bone is independent of blood marker levels since it doesnt seem to be included in most screening models yet. Perhaps this is more of a ultrasonographer training issue?
Peanut - if you don't mind me asking what were the risks and outcomes of your pregnancies? Do you know what made you high and low risk?

peanut08 Fri 07-Aug-09 19:17:25

Hi kittyTN,
Glad you found the article useful. I have become quite interested in screening and trying to make sense of how it works since having my 3rd child who was born with DS last year (diagnosed prenatally after 1 in 3 combined risk result) incidently he did have a nasal bone at 12 weeks but my consultant didn't regard the nasal bone screening as reliable anyway for some reason.

My first 2 pregnancies showed very different triple test results (nuchal test wasn't offered and I was in my mid twenties so didn't consider having it) one in the high thousands the other was about 1 in 200 although I declined any further tests and both babies were born with no chromosomal abnormalities.
I'm sorry I can be of no further help with regards to how testing works, statistics etc but this is definitely the best place for advice, there are some very knowledgable ladies on here willing to share their experiences of testing.
Good luck in yor pregnancy smile

linspins Fri 07-Aug-09 21:11:13

Kitty, yes I'm still pregnant, 16 weeks tomorrow (and it's pregnancy number 4 cos we had a lovely girl too, almost 3 years ago, all healthy).
Off for more scans tues at Kings. Deep breath.
Good luck at the FMC, they'll be able to check so much, not just nasal bone.
I think your odds are brilliant, so should be all good.

KittyTN Mon 10-Aug-09 21:32:13

Peanut - screening certainly seems to be an emotional roller coaster. I suppose if ds hadnt had such a low risk, then perhaps I wouldnt be quite so unhinged by my current 1 in 1700 - assuming I even trust this result! Perhaps you would have felt the same with your vastly different risks with dc1 and 2.

Linspins- good luck at King's tomorrow. We are due at roughly the same time. I have seen you on another thread - what a tough time you have had - I really hope you get some reassurance tomorrow. Are you booked at Pembury? I am in Kent too - either Pembury or home delivery for me! I will update this thread after my anomaly scan. Thanks to everyone for their input.

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