How does percentile translate into birth weight?

[Unicorn007]

Hi! Currently 34 weeks, baby has been measuring at 97th percentile for past 8 weeks. Consultant took measurements from head circumference, stomach and thigh bone. Think this means (from google) that our little girl will be bigger than 97% of babies at same stage?
So of course now I am terrified that I'm going to have to push out a whopper baby!
Can anyone who has been in the same position offer any insight into what her final birth weight could be? I am imagining 10-11 pounds and now really scared!

[BonaDea]

They can tell you more specifically what the projected birth weight is - in fact on your scan notes, is there not a graph where it tracks birth weight? I simply asked the last time I was there, and they were able to project forward the estimated weight.

I would also say that I have heard so many people say that these scans can be quite inaccurate. For example, things like femur length can be off depending on the angle of the baby's leg to the screen (this is what my consultant told me on Tuesday!) and with head size they base the growth not on circumferance but from ear to ear - that measurement can be affected by the shape of baby's head. If your baby has a round shaped head, the ear to ear measurement is obviously larger than if that have an oval shaped head which is narrower from ear to ear.

I'm also on the 97th percentile by the way, and also pannicking, but just trying to provide some assurance that 11lb baby is unlikely! And if they are really really worried about size or something is amiss, they will potentially induce you a week or so early...

[shelly81]

Ladies these scans are so unreliable & very rarely correct with DS 2 I was told he was 8lb & not an ounce bigger ..... He was 10lb 2oz 4 hour labour easy peasy no stitches home in 6 hours just hoping dc3 is the same haha xx

[WillowB]

My DS was measuring on 75th centile all the way through my pg. Was born on the 9th!! A teeny tiny 6lb 3oz. Must have been all the water!

[TerracottaPie]

My growth scans showed a 97th centile baby too...11lb exactly when he came out

But mostly the scans are just used as a guide and not wholly accurate.

[MrsMiniversCharlady]

My serial growth scans showed a 50th centile baby - he was a smidge under 11bz (Was a v easy labour btw)