Mine didn't, I'd say I was up around 33-35 BMI. He only encouraged me to lose weight. Same as Naomi, every bit counts. I lost 15kg, had success but mc-ed, did an FET and had my son. Then I went back again after gaining more and I was at least a 35BMI. It was an epic failure. One poor quality Day 4 that failed and no spares. I also had 2 natural pregs that mc-ed. I went away, lost 30kg and went back and am now 16wks with twins.

You don't have to lose weight, but its great if you can. It really makes so much of a difference in so many aspects of your life. I guess for me it came down to the fact that I wanted my babies more than anything in the world and I was prepared to do whatever it took to get them.