WHY are babies getting bigger?!

[mersmam]

I've heard a lot of midwives saying that babies are getting bigger, and anecdotal evidence seems to support this.I was speaking to a midwife last week who said that she thinks the average baby she delivers is about a pound bigger than the average baby of 10 years ago. I'm really interested to know why this is the case. I presume it's mainly beeter nutrition - but is nutrition really that much better now than it was 10 years ago???
I'm particularly interested to know because I'm expecting my 4th dc and my third was rather on the large side... I'd love to know if there's anything 'healthy' (ie. not starting smoking!) I can do to keep my baby a 'reasonable size' (anything under 9lbs would be good!)
I'm slim normally (only about 8- 8.5 stones and 5foot6) - I eat fairly normally during my pregnancies and have usually put on around 2- 2.5 stones (and normally lost it again within a few months of breastfeeding) - so I don't think that putting on too much weight through eating too much is what is making my babies big(in my case anyway!. My husband is not particularly tall...
Any other ideas or knowledge of research to show what makes a baby big??

Psycho, I remember when DS2 was born and H and I were cooing over him going "oh, isn't he tiny!" The midwives looked at us as if we were mad and told us that actually, he was rather big. We laughed at them. They did agree that he was comparatively tiny when we explained

I haven't a clue on this topic. My great Uncle (born just after WWII) was 12lb 9 my FIL (almost 60) was 13lb 10 so on both sides mine and hubby's there are big babies. My mum had 4 children i was 7lb 6, 3rd baby was 7lb 15 and her last was 6lb 5she was very overweight by her last child.

Then there's me my first born @38 weeks was 7lb 3oz, second @37 weeks was 7lb 15, they were both boys both average sizes if you take away when they were born. My last 2 have been girls, dd#1 @39 weeks was 9lb 12 and the one I've just had was @38 weeks a whopping 11lb 8oz.

I haven't a clue where that came from i was at my most healthiest, am 32, the mw's told me no sugar as soon as i started measuring big, so no treats for me no biscuits, crisps (not a big fan anyway), no cakes, choc or sweets no sugar drinks which isn't a problem as i only drink water. At 35 wks i measured 50cm :O I had to have a section with her as well as my 9lb 12er got stuck when i had her and this one was looking bigger and they didn't want to take the chance with the complications I had with her so i've heard people say you only have babies as big as you can get out but my pelvis isn't big enough to do this size i had massive problems getting out 9lb12

Lost track of what I was saying now as she needed a nappy change.

My old fashioned pregnancy book says a woman will have her heaviest baby when she is about 35.

In the old days that would have been her last baby. Nowadays that's likely to be her first.

I had a big baby at 35. The second and third I had at 37 and 43, and were both an (identical) small weight.

I saw the consultant when pg with baby 3 as I was worried he was too small. Consultant said, in that patronising consultanty manner, that first babies are always bigger as the mothers have the time to lie around eating mars bars all day, whereas with subsequent pregnancies they don't.

There doesn't seem to be much of a pattern to me from what has been said. I am quite small at 5'3" and usually weigh around 8 stone, and all of my babies have been nice and manageable (7lb3oz, 6lb8oz and 6lb10oz) so I am hoping my fourth (due in April) will be similar size. I always rationalised that it would come out at a size that your body can cope with although my sister had a couple of whoppers so I suppose there are exceptions! I have also heard that the baby tends to be the median of your birth weight and your husbands which rings quite true in my situation.

noty much of a pattern here either..I am 5ft8, very overweight DS was 9lb10z 15days past due date. I was told both DDs by 36wks were over 10lbs from scans etc and was induced at 39wks[dd1] and 38wks[dd2] yet dfespite scans and the oh your babies are huge converstations they were both 6lb14ozs but I had a LOT of water with them both where DS had dried out. Now expecting DD3 so am awaiting the whole your DD3 is huge converstations..

this is the article I was thinking of when I said overweight women were more likely to give birth to very big babies or very small babies.
'Obese women were nearly twice as likely to give birth to a low-weight baby, weighing less than 5lbs 8oz (2.5kg). '

I think it's to do with hight rates of preeclampsia and high blood pressure, which hinder the nutrition of the baby.

Hmmm... a lot of interesting posts. The fact that women are having babies later, and smoking less during pregnancy, does make sense as a cause of babies getting bigger I think.
It's very scary to read that your biggest baby will come when you're 35, as I'm 34 now and expecting my 4th - had my 3rd when I was 32 and he was 9lbs 4oz so this one is likely to be bigger!

I found this which indicates that babies ARE in fact getting bigger and that:

''Probably the key factor contributing to larger babies is not a woman?s weight gain during pregnancy but her weight before. A mother?s size has far more effect on how big her baby will be than a father?s. That means small women tend to have smaller babies and large women tend to have larger babies, irrespective of the father?s size. Overall, says Kramer, Canadian mothers? body mass index (BMI), a measure of weight to relative height, ?has gone up a lot and shows no signs of slowing down.?''

However, in my case that doesn't make sense as my normal non-pregnancy BMI is in the underweight category... so I guess the size of my babies must be due to not smoking and being nearly 35 (not much I can do about it then!)

Interesting to read that a baby is normally mid-way between the birthweights of the parents - but again not true in my case. Dh and me were both around 7 lbs but our babies have ranged from 8 lbs 3 to 9 lbs 4... However, dh's mother smoked during her pregnancy so perhaps if she hadn't he would have been an 11 pounder - that would explain it

As all babies are weighed at birth it would be realatively easy for to have study baby weights;if they are increaing, and by how much.

My babies got smaller as I got older.

I have to say that I'm not sure amount of weight put on during pg affected mine?

I gained 4 stone when pg with DD1 and she was 10lb4!

I only put on 19lbs with DD2 and she was 11lb1

DD3 was 9lb14oz and my diet was pretty strict as I was a late diagnosis of GD

I stopped smoking when I fell pregnant the first time - which I subsequently miscarried and never started again BUT I did put on weight and still carry it now

My personal opinion is diet. Sugar is in everything nowadays. I however had a 10lb 5 oz DS at 22, and followed a diabetic diet as much as I could as I am large. I stayed the same weight throughout but he was still massive I ate alot of junk with DS1 and he was 6lb 6oz - I put on 2.5 stone. There will always be exceptions but I do think , in general, it's diet.

I was 7 1/2 lbs and my sister was 8 1/2 lbs - I have produced babies of 8 1/2 lbs, 8 11 and 7 15 so I would have to say that my family experience suggests babies are the same size they've always been!

I suspect that the change in midwives scales could have something to do with this. They used to use the spring and sling type of scale a lot more. Now it's almost universally digital - who's to say that these different scales are actually weighing as accurately as the other?