Hi there,
I really don't know the answer to your question, but I wanted to share our experience with echogenic bowel. We found out that our youngest had echogenic and dilated bowel at around 30 weeks. I hade been getting monthly u/s starting at around 20 weeks since my oldest had MI, but nothing showed up until later. We then had an amnio to confirm the CF diagonsis, though it was a little silly to get it in retrospect. Our LO's bowel was hardly echogenic, though. Depending on which doctor I saw for the U/S, they would not even say it was echogenic. The main thing we saw was the dilated loop. That was very evident at around 30 weeks and continued to get worse until it perferated and I was induced at 37 weeks. So, I do have a point, and that is some times the echogenicity isn't the whole picture. And, depending on which doctor I saw, my LOs bowel wasn't echogenic. I think echogenicity is a very subjective thing and not always consistent between techs or even doctors.
Good luck and I hope all goes well.
Dara