I think the guys have given great advice there. Have a look of the two threads Dutchie posted over there.

From my personal experience, I've had 5 failed IVF cycles (bar one missed m/c) until I found out that my NK level is very high, which hinder the implantation and cause m/c. I wish I'd know earlier especially I am not at the spring chicken age either , so I haven't wasted those perfect embies in the past. So I do want to let all the ladies out there who have done more than 3 failed cycles to have these tests done before embark on another cycle. The tests are not expensive and you will get the result quite quickly.

Good luck.