How accurate are ultrasound tech when measuring babys weight?
At this point, in the 2nd trimester, they’re relatively accurate. However, in the 3rd trimester, they’re notoriously unreliable for sizing! They won’t tell you that, but they tend to be off (toward the end) by as much as 25%! Docs frequently use ultrasound and the spectre of a “big” baby to scare women into inducing unnecessarily, even early!
The nearer to term, the less accurate. I went over with all my babies and had ultrasounds at 41 weeks to monitor fluid etc. all 3 times they said between 3 and 3.5 kg and my first was 4.8kg, my second 4.2 kg and my third 4.5 kg. Maybe they didn’t want to scare me:-)-lol! But I think at that point they’re done developing and pretty much just gaining weight.
