Beside selective abortion and embryo selection, it's already possible to derive gametes of both kinds from stem cells of arbitrary sex in mice, and it will most likely be possible to do the same with human cells soon.

Mice that descend from two males or two females have already been created in the lab.

You still need wombs, but they can be grafted and will probably be farmed from stem cells in the future too.

https://en.wikipedia.org/wiki/Uterus_transplantation#First_s...