Good thread. Possibly an urban myth, but there seems to be some truth to it:

SIL and BIL were on IVf for 8 years with male and female infertility, conceived twins on a double FET, concieved naturally 9 months after the birth - blighted ovum though. The fact that they conceived naturally at all is a miracle.

I wonder whether I'll ever conceive naturally - what a novel concept!