# What factors will determine your baby's birth weight?



## vikster

Quite a few people I know have had babies recently, all 8 pounds something. When speaking about this in work the other day some reactions to the birth weights was that 8 pounds something was big which got me thinking - what factors affect or impact the weight of your babyat birth? 

I was 6lb 1, my brother was 6lb 2 at birth. Both parents, grand parents, aunties and uncles are slim and there is no history of being overweight in our family. I am 5ft 4 and a size 10 and hubby is 6ft 2 and average weight for his height but large build (broad shoulders), I think he was 8lb something at birth but mum and nan are both overweight. We both exercise a few times a week and try to eat healthily but we do like the odd glass of wine and take away.

Is genetics solely what makes up your baby birth weight or is it outside factors? Some of my friends have been bigger girls, piled on weight during pregnancy and been huge with massive bumps but only had teeny babies.


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## OmiOmen

8lbs something it more average than big. My husband and his sister were both 10lbs 1oz, my friends son who was born the same day as mine was 10lbs 4oz, that is big! 

How much you eat, if you drink (too much) caffeine, smoke or drink are also factors that can affect birth weight. 

My son is tall (although slim/muscular) but was 6lbs 14oz when born. He was on the 25th centile and about 3 weeks later was 99.9th for hight and 95th for weight. I was told he would be larger side of average on the scans the weeks before he was born too. I know a lot of people would call me silly but my husband is 6'4" and bulky and I am sure my son takes after him and my little belly just was not going to grow a 10lbs+ baby. :shrug: I was 5lbs 12oz and my too sisters were around the 6lbs mark but my mum smoked while pregnant.


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## sequeena

From what I've been told the mother deyermines the weight. Not sure how true that is.

I was 5lbs 1oz born at 34 weeks. I'd have been 7-8lbs if I made it to term. My OH was 8lbs 12oz.

Thomas was 6lbs 8.5oz but I had low amniotic fluid which hampered his weight.

ETA: My son was born at 40+3


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## calliebaby

My husband was 8lbs 5oz and I was 6lbs 13oz. Our son was almost 3 weeks early and was 6lbs 9oz. He probably would have been around 7 and a half pounds if I went the full 40 weeks.


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## goddess25

My son was 8.10 at birth and he was very long...he still is going to be tall and a reasonable build. My daughter was 7.10 at birth and quite long too but she is quite little now for being 1. I am overweight but I eat healthily and I do a tonne of exercise. I was 4lb at birth but was premature and my hubby was around 8.10 at birth.

8lb something is pretty average I would not say they are big babies at all.


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## lepaskilf

I don't think your birthweight has any impact on your size when you're older, unless ofcourse you were really small like 3lb, then you might be naturally small!

My lo was 6lb8oz when he was born, 4 weeks early. The midwife commented on how tall he was but my OH is 6'2 so that was expected but you could never tell he was early or anything now!

My friend's lo was 5lb2oz at full term and again 2 years later you could never tell! He looks like any other average weight toddler x


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## I Love Lucy

My sister and I were both around 6-7 lbs when we were born. And I believe that was the same for OH's side of the family. I always though genetics for the most part would determine the birth weight along with whether or not the baby came early or late.


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## sun

I was 8.5lbs and my OH was 12lbs at birth so I was really concerned about having a 10+lb baby. Genetics plays a decent role in weight (as well as maternal health, etc) so I was expecting a giant baby. And my kiddos were both very large for their gestation - my son was 6lbs 11oz at 35+6 weeks and my daughter was 7lbs4oz at 36+5 weeks. They estimate both would have been around 9-10lbs if they made it to my due date lol! I'm quite small so I think my body knew they had to get out early or not at all :rofl:


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## Pearls18

When your born your weight is charted and they are called centiles- an average centile is 50, up to 98th is above average (it is seen as if you are bigger than 98% of babies your age) and then lower (my bubba was always big so I don't know what they are below 50!) What you are at birth does not necessarily impact your centile as a baby, toddler and beyond. The factors that I am aware of for birth weight is genetics (both myself, my mum and DH were small to average babies 6-7lb ish) -Elliot was 7lb 11.5 oz- I believe eating A LOT or not enough can have an affect, and of course smoking, drinking, and caffeine can make your baby smaller. So Elliot was on the 50th when he was born, by 8 weeks he was on the 75th centile, and by the time he was 6 months he was on the 91st centile (20lb having only ever had breast milk not even solids...I was very impressed with that haha) so I was naturally worried it would mean he'd be a fat child haha -even though he doesn't look at all fat because he is tall for his age also- but the HV has assured me that genetics do play a big part and because DH and I aren't big Elliot isn't likely to be, unless I completely over feed him obviously lol. Last time I weighed him he was on the 75th, since becoming more active he is regulating himself.

Bare in mind how long you carry your child can affect the weight (I do know a woman who went 2 weeks over and had a 5lb baby mind!) because after so many weeks of pregnancy (can't remember what point) your baby is putting on average about 1/2 a pound a week so going over could naturally mean you have a bigger baby.

And whatever you do, don't panic about the size of your baby when pregnant, even in 2012 they don't have an accurate way to measure your baby's size, I was told I was on track for a 10lb baby!! Even the growth scans are rubbish!

Oh and one more thing- it is common for the next baby to be bigger than previous children, no idea why, but bare in mind how long a baby is gestating for as well because later babies tend to be born earlier also so in that case the baby might not be bigger- not always!


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## cj28

My little girl was only 5lb 15oz and born on her due date. I only put on 1.5 stone during my whole pregnancy despite eating non stop - I think pregnancy must have speeded up my metabolism as usually I put on weight fairly easily.

My DD is still petite now - she is still in some 9-12 month clothes at nearly 20 months - but neither me or OH are very petite so not sure where its come from :shrug: She never stops eating either!!

Its another thing I can't wait to see - if I'll be bigger this time and if baby #2 will be another teenie one or a big chunk?! :happydance:


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## vikster

Marine wag, thanks for the info, it has explained a lot. The thought of pushing out a baby makes me wince a little let alone a big baby! The episode of OBEM when the baby got stuck was awful but when they revealed that she was over 10lbs I wasn't surprised lol. Oh well, as long as baba is healthy that is all that matters xx


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## Pearls18

vikster said:


> Marine wag, thanks for the info, it has explained a lot. The thought of pushing out a baby makes me wince a little let alone a big baby! The episode of OBEM when the baby got stuck was awful but when they revealed that she was over 10lbs I wasn't surprised lol. Oh well, as long as baba is healthy that is all that matters xx

Some midwives claim that bigger babies are no different to push out that smaller babies, it's not the weight that matters so much but the bone structure- a bigger head will cause more difficulty than an extra pound of fat, and the woman's body itself obviously. Bigger babies are meant to be healthier and better behaved babies than smaller babies....don't know if that's true or just some consilation for the mum lol, but I know it made me less stressed in that first week of BF when you panic about weight loss that Elliot already had some good weight to him- as it happened he gained 2 oz!x


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## calliebaby

The day I went into labor, my obgyn felt my stomach and estimated my baby to be around 7lbs. She was sooo close! He was 6lbs 9oz. :haha:


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## knobby

I don't think the parents' weight, whether they are skinny or obese, has a lot to do with the baby's weight. Babies are so close in weight anyway no matter how big the mother is... all around 7-8lbs give or take - it mostly has to do with gestational age. But of course, sometimes there is no explanation for a baby that is really big or really small at birth.

Smaller babies that are considered underweight for their gestational age are underweight for reasons like drugs or the mother did not eat well during pregnancy. Hyperemesis gravidarum also can cause the baby to be underweight.

Gestational diabetes can cause babies to be larger. The medical term for this is macrosomia and is very common in babies whose mothers had gestational diabetes.


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## bathbabe

Personally i think its all bull :D

H was 5lb 12oz 4weeks early. EVERYBODY told me i was going to have a huge baby a midwife (who only saw me at a glance and didnt know me from adam) told me that i looked like i was about to pop and after i told her that i was only 32 weeks her exact words were "Have they told you your gunna have a big baby, coz it is" I had a growth scan where everything was normal but they still said they thought he was gunna be big :dohh: Even if id gone full term he wouldnt of been any bigger than 7.5lbs ish :shrug:


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## MindUtopia

Also, being on inhaled steroids (like those in asthma inhalers) can cause birth weight to be smaller. Supposedly, if you are on inhalers, it's less risk to stay on them than to stop and have problems getting enough oxygen for the baby, but I've personally thought about trying to wean myself off of mine in advance so that I wouldn't have to worry about it. I was a small baby (I just found my baby book the other day and I was 6 lb 1 oz), so it does make me think a bit about it all.


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## OliviaRae

Not sure.... I am petite (5' 1" and 120 lbs) and I'd like to think that I won't have a giant baby! :dohh: My friend is smaller than me, very slim, and she had a 10 lb baby and they had to break his collarbone to get him out :nope:


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