C.H.
Hi C.!
I can't answer the guarantee question. However, I've been through countless unsuccessful IUIs, 3 IVFS and 3 rounds of frozen transfers from which I have 2 beautiful children. My advice if you do decide to go forward is to start a low carb diet immediately (the Protein Power book was recommended by my docs). I won't go into why it seems to help buy I am absolutely convinced it was what allowed the successful IVF cycles. I know several other women who have had the same experience (thin or not at the onset). The diet stinks but it is short term and well worth it. The second thing is that if you go through it, it is all about attitude. Know that it will work for you because it is your turn and it will!
Best of luck to you!
C.