Hi hun. When I got pg the first time I was already 38. I can't remember what my result was at the 12 week mark, but it was OK, but I do remember my OB saying that for my age, anything above 200 is good. He did say that there is a very small chance that I could miscarry a healthy pg if I went ahead with the amnio, so he said 'why risk it when you went to all the trouble with IVF alrerady' ? I trusted him and went ahead with the pg, and I had a healthy baby (although I lost my first LO to an unrelated problem). I guess your OB could be swaying on the 'cautious' side as risks rise when you've over 35, but it seems to me like he is overly cautious. I think 1:350 is pretty good hun. Weigh up everything you've been told so far, ask more questions if you need to, and then make an informed decision that feels 'right' for you. GL hun xox