people who struggle to concieve naturally choose to use IVF to have a baby, so why cant people who struggle to have twins naturally use IVF?
Just wanted to point out that if you can't conceive naturally, then IVF is not a choice, but likely your only option.

That's quite different to wanting IVF for the express purpose of having two babies at the same time, and therefore putting both you and your unborn children at exponentially more risk, just for vanity and convenience.