Big baby at 20 wk scan: should I be worried (I am!)?

[Catz]

I've just got back from the 20 wk scan and am a bit concerned at the huge baby that I seem to be expecting... I'd be really grateful if anyone has any advice or experience.

It's a boy and I am 20+4 (or 20+5 by my dates) today. The measurements for biparietal diameter (54mm) and abdominal circumference (174mm) are way off the scale which is worrying as I read they are the most accurate predictors of foetal weight. The estimated weight is already 1lb which is pretty much at the top of the scale. All the other measurements are at the high end too. I know that scan measurements aren't always accurate but these are all large and considerably larger that would be expected.

I had DD 2 yrs ago and she was fairly average at 7lb 5oz at birth (40+5). I'm usually a size 8, 5ft 4 with narrow hips so not tiny but certainly not large. I'm quite worried about the delivery as DD got fairly stuck last time and needed ventouse and large episiotomy and I still tore a bit. I'm seeing my midwife on Friday anyway. Is there anything I should be asking at this stage...

Thanks for advice/experience.

[Scorps]

If they were worried, they would have said. You may have an 8-9lber, but that is do-able at your weight and height. I know several friends who are similar to you in build (myself included - i had 6lb 11, 8lb 1 and 8lb 9)and it was all fine.

If MW suspects big baby at 35ish weeks you coulkd request a growth scan to see if you have pelvic disproportion, but it is rare for your body to make a baby bigger than it can birth (if you're healthy). Well done on your lovely boy (saw on our AN thread)

[Scorps]

Also, for the majority of women, second births are alot easier, and your first baby may have been awkward iyswim

[suwoo]

I've just had a look at my scan notes to compare and those are indeed mahoosive .

My baby is predicted to be about 8lb when he is delivered at 38 weeks (8 days) and his measurements were

BPD 43mm and AC 151mm.

My other two were 8.13 and 8.8 (39 weeks) but I have no idea of their measurements at scan.

Good luck

[Catz]

HI Scorps, thanks for the quick replies. The sonographer did say that they'd probably have to do further scans to check growth but to talk to midwife as midwife/GP will refer if needed.

Looks like he'd be on the 99th percentile for weight at the moment and is way of the scale for the other 2 so I'm guessing that if he kept on the curve (which I know they don't always) then it'd be way above 9lb (can't find the charts at the moment hmm where is DD's red book)

Am going to stop eating...

[Catz]

Thanks suwoo!
If your baby being delivered early because of weight or other reasons? Good luck for the delivery.

[Catz]

Just bumping as panicking a bit!
From what I can see online he is measuring abut 2 weeks ahead of where he should be and is off the charts on the measurements for dates.

[Scorps]

Are you very certain of your dates?

[suwoo]

No, I'm being delivered early for convenience but I am having an elective for genuine medical reasons.

My baby certainly feels really big to me, but who knows. I don't think your eating habits have much of a bearing on it, so don't stress about that. Gestational diabetes can cause big babies though, so maybe they'll check you for that?

[Catz]

Hi Scorps, yes completely sure. Had 28-30 day cycle and was using ov sticks, 12 wk scan matched my dates (well put it at one day earlier). It's certainly not any further on than my estimated date.

I'm sure my mw will just say, don't worry about it but my mum also had a roughly 10lb boy and had a complete nightmare with the delivery so that combined with my 2 day, assisted delivery last time means I am going to worry about it for the next 5 months! From what I can see online they don't recommend induction or c/section for large baby anyway unless there are other problems so I guess I will just be left to get on with it.

[mumbot]

I read recently that head size has more to do with delivery difficulties than weight. Not sure if that helps or not but thought I would mention it.

Try not to worry about the things that are outside of your control x

[Catz]

Thanks Mumbot - unfortunately biparietal diameter (which is of the graph) is the diameter of (one particular part of) the head and the head circumference is also large (though not off the graph).

I am trying to make sure that I know any potential issues no so I can raise any queries with mw now, given I won't see her again for months. I want to be fully informed, if, for example, they recommended early induction above a certain weight (which I don't think they actually will) I'd want to make sure that I'd read about it to see whether I wanted to consent to that plan. I also want to make sure that I know whether it's worth pushing to be scanned again at a later date to see what's happening. I strongly suspect that she will just say get on with it and if there is a problem in labour we'll deal with it then but at the moment I'm not comfortable with that. That's why I am worrying about it now.

[suwoo]

Catz, you sound like me, I overthink everything. I'd be doing the same as you, but I suspect there is not much that will be said or done to alleviate your concerns.

[ErikaMaye]

My little boy's head circ. (am 23+2) was right on the end of the scale and I was really worried, but when I spoke to my MW she said it was normal, and that things grow differently in different babies. If they were worried they'd have said something, and I'm sure its the same for you

Congrats on your little boy!!