What is rate of baby growth in utereo?

[lillymonster]

My last baby was 8 pounds and I had a biophysical profile at 37 weeks and she was 7 1/2 pounds. I just expected next baby to be larger, I just had a bio profile at 32 weeks and this baby is 4 1/2 pounds. I was told that was spot on where she was supposed to be. In fact, I saw the screen after the OB left and it said "gestational age: 32 weeks 3 days" which is actually when I ovulated, so that is even weirder it's that spot on.

But anyway, what are they using to judge this size? What is the "final" size they base that on? I read in a magazine right before I went in that the average size of a US baby was 8 pounds, and I can't imagine my baby will add 4 pounds in 8 weeks. I know the ultrasound can be off 2 pounds either way - I am just curious what the medical field bases this gestational age on.

[EllisH]

Actually, half a pound a week of weight gain is just what my pregnancy book says is the baby's growth rate for 32+ weeks.  So it all does add up :-)

[lillymonster]

Originally Posted by EllisH 

Actually, half a pound a week of weight gain is just what my pregnancy book says is the baby's growth rate for 32+ weeks.  So it all does add up :-)

oh wow, I didn't realize they grew that much! well that makes me feel better.

[~Adorkable~]

yeah my babies are 3.3 and 3.8 pounds at 30 weeks, and i was told they were spot on either side of the average, so that sounds perfectly in line to where yours is as well, i have also hear that at this point growth is faster and the .5 a weeks sounds right