The practice that I go to did a 3rd trimester ultrasound it's called a growth ultrasound i think they did mine at 32 weeks ... That is when they told me a estimate about the baby's weight

Feel, measuring your uterus and years of schooling.

I don't think most do. . I had no idea how much my LO weighted.. she ended up being 8 15 and 2 weeks early.

so how do they determine baby's weight then? @wiccanmommy

no not most people. lots of insurance companies don't cover extras unless it's a medical reason. I had one at the begining to determine gestation and then at 20 weeks. that's it.