Fetal weight

Lusitano8 · December 2015

Hi all, at our 20 week ultrasound the tech said baby is about 13 oz based on their measurements. I was wondering what the avereage is and at 20 weeks this chart says about 11 oz, so is 2 oz a big discrepency at this age? https://www.babycenter.com/average-fetal-length-weight-chart

STM's or anyone know how accurate these predictions are? Will a big baby at 20 weeks mean a big baby at delivery?
Anyone else want to share what their baby's size is? Thanks!

cortney626 · December 2015

They're estimates and it fluctuates so much. At 19 weeks I had my A/S and they said she was 12 oz. But they're not considering her a big baby.

kbrands7 · December 2015

They're not too accurate-- both because it's hard to estimate weigh as opposed to length/width which are more exact, and also because babies go through growth spurts in the womb just like during their first year. DS had been estimated to be nearly 9lbs by birth...he was tall, but not quite 7.5lbs at birth.

Bluejay3030 · December 2015

As others said, the weight measurements aren't terribly accurate. Our MFM estimated our DD would be 6 lbs at birth and she was exactly right, but that's the only time I've ever heard of the weight being right.

This LO was estimated to be 10 oz at 19 weeks, but who knows. I wouldn't worry about having a big baby just because it's measuring ahead right now.

JessicaB0627 · December 2015

Like PPs said, babies can go through growth spurts at different times. I definitely wouldn't worry about how big your baby will be based on the 20 weeks weight estimate.

Bltbear82 · December 2015

If I remember correctly I think the fetal weight calculation is +/- 1 lb so that gives a fairly big swing, so I don't think a few ounces even at this stage should be any cause for concern. DS was projected to be over 7lbs and was born 6.13.

LadySamLady · December 2015

We had our A/S at 20 weeks and my LO weighed in at 1lb. According to my OB this puts her in the 98th percentile and she will likely be over 8lbs at birth. She said its all about genetics at this stage and nothing to do with what I'm eating etc. My H was 10lbs when he was born and I was nearly 9 so I expect she may be as big as they predict but hoping PPs are right...

Eta: and you thought 13oz was big...

AdorkablePixie · December 2015

@LadySamLady My husband was 10lbs too, actually just over. I think I was close to 8. I am so scared I'm going to have a huge baby!

AdorkablePixie · December 2015

My doctor hasn't even given me a weight. We had out A/S on Monday and they said nothing about it.

proudparent2b · December 2015

I have no idea what my baby's weight is either- had sonograph today. My kid was curled up and uncooperative so the tech had difficulty getting certain measurements.

I'm sure things have changed since I was born, but because my mom's doctor thought I'd be 14 pounds and I was only around eight, I don't put a ton of stock in the weight estimates.

artteacher19 · December 2015

We had our AS at 20 weeks on Monday, and measured exactly the same at 13oz. They said it was totally normal, so I wouldn't worry!

lalala2004 · December 2015

I hear more about these predictions being off than not. Plus, in order for there to be an average, you have to have babies on the bigger and smaller ends!

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