Amniocentesis at 34 weeks because of large baby

[stefania]

I am 31 weeks pregnant with my thrid child and he has been declared large for his gestational age (about 3-4 ahead but doctors say due date is still correct). I have been told he is simply a big baby and will have to be delivered early but there is a miniscule chance that he could have a cromosome problem and that's why he's large (diabetes has been ruled out and size of parents is fine). i have 2 questions has anyone been diagnosed with a Large for Gestational Age baby and anyone had such a late amnio?

thank you so much for any help.

bumping for you

haven't heard of this stefania....well, not the late amnio ...

how large were your first 2 babies?

were there any markers at previous scans that might indicate a chromosomal defect?

Aren't there still risks from amnio at this age? Could it send you into premature labour? Would you be okay about that? If not, what is the benefit of knowing at this point?

I would just want to be sure that any risks were worth the possible benefits of finding out at this point.

agree flack....sounds very invasive...there is always a risk with amnio..and at a late stage where the baby is filling more of the uterus, there will surely be more of a risk....

Sometimes the needle from the amnio hits and damages the fetus. I mean it's extremely rare, but I think that's more likely if the baby is big and active (no?).

I am sorry if I upset anyone by saying this. Suppose the fetus has a really horrendous defect and mother knows she might want to terminate (if she could get 2 doctors to sign it off the late abortion for a terrible deformity). Then I could understand taking the risk.

But otherwise, the risk from amnio would have to be very small to create any worthwhile benefits from knowing about a chromosone defect only a few weeks early, I would have thought... (but maybe I'm terribly misinformed...?)

have to agree flack........that is why i asked about any markers showing up at 20 week scan...

i was measuring 3 weeks ahead at 34 weeks..had a growth scan..average sized baby..it's just the way i carry...LO born at term weighing 7 lb 8...

large for dates is not really an indicator of a chromosomal defect....IMHO....

Is he declared large by scan or by external palpation? External palpation is not very accurate. I hardly see the point in undergoing the risks of amnio at this late stage, other than so that you can be forewarned.

Are they predicting a birthweight? Or at least saying on what centile the baby's current size lies? And how big are you - wide child-bearing hips, or sylph-like?

FWIW my ds2's abdominal circumference was coming up as 95th centile at 35 and 37w, and I was being given dire threats of not being able to birth him normally, but, having birhted two previous babies who measured 75th and 91st centile by scan, I was confident that it would be all right, and it was - I had an 11lb baby without stitches. We expected large, but not quite so large! And he's fine, perfectly normal.

I had amnios at 34 weeks and 37 weeks with DS: my waters had broken many weeks before, my consultants were worried about infection and failing placenta, and needed to check the maturity of his lungs (apparently amnios can disclose this). The consultant was guided by the ultrasound pictures, and even though I had little fluid he found a nice isolated pocket so no harm to DS, and no danger of him waving something into the path of the needle. No ill effects at all (and less painful than earlier on).

Having said all this, I cannot guess whether the procedure is necessary or informative for a 'big for dates' baby, only that it went well in my case.

Have had a CVS and baby with an abnormality but not so alte and for different reasons. My thoughts would be what is the abnormality and what would I do if baby had it?

I am with west country lass - what do they think the chromosonal problem could be and what would you do if it turned out the baby has some sort of condition.

If the answer is nothing but go on and have the baby then why take the risk. Just my thoughts. I see you say there is a miniscule chance....

Dd was predicted to be a large baby after 2 growth scans. Her head was going to be large and her abdomen size was off the charts. Ds1 and ds2 were fairly big babies at 9lbs 8oz and 9lbs (at 38wks). When dd was born she weighed just 8lbs 4oz, with a small-average head and a long slim body. She bore absolutely no resemblance to the huge baby that had been predicted from the scans.

I was diagnosed with large baby (if that is the right way of describing it!). However this was by scan at 36 weeeks. Had one appointment with obs. She jsut let me get on with it. DS born at 41+4 weeks at over 11 lbs.

Agree if you would not termiante think there is little point in risking an amnio.

I have never seen an amnio be suggested for a suspected large baby at this gestation I have to say. Babies with chromosomal abnormalities usually tend to be smaller than larger. Where do you live Stefania? Is it in the UK?

Thank you so much for all your replies. They are only giving me an amnio because i insisted so much, i asked for it earlier in the pregnancy and they said no. The baby's weight is estimated to be 2.2kg (5lb) at 31 wks when it should be 1.5kg (3lb)and is on the 97th centile, they have found no markers but they still say they couldn't guarantee that they baby has no defects. i would terminate even at this late stage if there was a serious problem with the baby.

stefania...if there are no defects visible on the scan, and it is simply the size of baby you are concerned about....i 'm not sure i understand..,esp.if your health care providers are reluctant to do an amnio..

you seem really fearful that there is something very wrong...why?

how big were you first two children..?

if too personal, no need to answer...just seems that you are really concerned...

I think an amnio is a pretty risky thing to do unecessarily. I am really surprised your care providers are agreeing to it. Scanning for fetal size is notoriously unpredicatable. Some babies are just large. I delieverd a friends baby who was 12lb 2oz at birth. He was perfectly normal.

I suppose they could be looking for something like Beckwith Weidemann syndrome by amnio, but it is awfully late to be having an amnio for something that's not necessarily life-threatening.

Stefania, I was scanned about 4 times with my DS2, my DS1 was 8lb 13oz and I am 5ft 9" and big built...the midwives were more concerned than the Consultant and I delivered an extremely healthy and bouncing 10lb 11oz baby boy, we did need the ventouse but I did with DS1 too...every scan said that the baby would be about 8-9lb, my last one was at about 37weeks, DS2 was born at 39weeks.
My friedn was told her baby was abnormally small from scans and she was born at 35weeks weighing 7lb...scans are not always correct.
Please don't worry.

They will always say that they cannot guarantee no defects - it is impossible, even with anmio, to guarantee no defects.

Oh yes, PrettyCandles is absolutely right, I had missed that- they will only be able to detect a very limited number of conditions with an amnio, especially as it's unlikely to be anything very severe at the chromosomal level if the pregnancy has got this far.

I consistently measured 5 weeks ahead, had growth scan at 35 weeks that estimated DS would be 10.5 lb at full term, diabetes ruled out (they were really disappointed about that... kept springing new blood tests on me whenever I went within sticking distance of a needle in an attempt to catch my blood sugar levels doing anything other than stubbornly behaving themselves), they actually wanted to move my due date up by a month at one point () except that I was 100% certain of my dates and stood up for myself, but no one ever even remotely in passing suggested an amnio. I find that suggestion a bit odd TBH. I mean, there's a minuscule chance that any baby could have a chromosome problem, large or not, but they don't routinely amnio all late-pregnancy women.

Eventually DS was born at 39+5, 10lb 5.5oz (which is around 98th percentile I think), perfectly fine. By definition 3% of babies are going to be 97th percentile or above - that's about 1 in 33 or one child in every school class who'll have been that sort of size. It's not anything to worry about by itself.

Stefania like you I am 31wks and have been told baby is measuring 35wks. Also third child and my DS was 9lb1 born and DD was 6lb14. Not been offered anything at all apart from to go back at 38wks to discuss if we should be inducing then rather than waiting/letting me go over.

Stefania (nd also dueat44) are you in the States? I know over there it's (or at least was) common, also before Elective C-section (to see for lungripeness), even at almost full term like 39 weeks, they would want to do an Amnio at that late stage!
The risk of the Baby being hurt surely must be higher then at a smaller stage.
Unless you would consider late termination, I personally would not see the point at having an amnio done at this late stage!