If they're so inaccurate, what's the point in growth scans??

[Rato]

My daughter was supposedly 6lb6 at 36 weeks. Expected to be born over 8 lb. she was 6lb6 at 38+5 weeks lol

 

[mod19]

You ladies seem to know a lot about percentile, so I have a question (sorry for hijacking someone else's thread).

I've been having scans at every appt for low amniotic fluid levels. 6 weeks ago they said she was measuring in the 30th percentile, but 2 weeks after that she was in the 50th. Can they really grow that fast in there? It was the same sonographer both times if I remember correctly.

 

[Amythyst]

Yes, they can have growth spurts like that. It also depends on the day that you have your scan... perhaps the baby wasn't "due" to get bigger till the next day or something after you get scanned and so they measure "behind". But then the next time you catch it on the right day and now suddenly they are "ahead". It could balance out depending on the timing and how your baby grows.

I had monthly growth scans starting at around 20 weeks or so. My stuff was usually all over the place. He was always "ahead" but the amount ahead varied greatly from month to month. One month he was 90th percentile measuring 2 weeks ahead and the next month he was 80th percentile and only 1 week ahead. Then he shot back up again a month later.

I was also very skeptical about their "estimations" cause I don't feel one formula fits all. At my 38 week appointment, baby was estimated to be 9 pounds 15 oz and in the 97th percentile. The only reason he wasn't in a higher percentile is because his femur bone was measuring 2 weeks behind. So, this brought his averages down. If you only looked at his head and stomach measurements, he was at like 42 weeks.

When I had my c-section last week, he was 9 pounds 3 oz instead of 9 pounds 15 oz ... so, it was fairly spot on.

 

[lam_76]

I had growth scans because im diabetic, i asked for an estimated weight at one but she said they don't give an estimated weight as it can be so inaccurate. I only got the abdominal circumference at my last scan at 38 weeks so i looked up the percentile for that then i played about with the calculators and worked out the weight for that percentile which was 7lb 8oz and he was born 3 days later weighing exactly that! Im not sure if it was a fluke though!

 

[SarahBear]

(Only read first post)

Unless there's a medical reason to be doing them, I say they're pointless! I haven't had an ultrasound with either of my pregnancies. Besides, a good midwife is better at estimating baby size than an ultrasound anyway.