Early IVF practices involved fresh embryo transfers, often resulting in multiple births due to the inability to freeze embryos.

“in a fresh Embryo transfer I'm going to take the eggs out of your body fertilize them in the lab and grow out embryos and then I'm going to put the best embryo back in your body 5 days later at the natural time of implantation and if we rewind the clock that's how IVF was done right when you couldn't freeze embryos very well and they didn't survive and you would put lots of embryos inside because they wouldn't survive and that's the early days of IVF when you saw a lot of multiples a lot of high order multiples”