In the future, because of bad things we did to the atmosphere and stuff, miscarriages are the common ending of a pregnancy, instead of being the exception. One evil company finds a way to accelerate the process by using 10 women, lowering the chances of miscarriage simply by reducing the time in womb.

I thought, something like a medication helping the women develop the baby in 30 days, but seriously damages the host in a couple of days, so the fetus gets transferred from host to host. Some die, but the evil rich don't care. Your idea could also work though.

I realize that this is totally the wrong corner of the internet to post this but I guess today I'll just go with it.

I'm too bad of a writer to be scared of giving my ideas away, but I'd explore a pupae stage, where (layman disclaimer, if it isn't abundantly clear from my incoming butchering of the science) the butterfly is basically melted down into a goop with no "brain part" or "feet part" of the goop existing until reformed, yet retain their memories. If you divided that goop up and imagined there was a gestation time reduction, before combining it for the final stage of formation, you'd have some "plausible" (loose definition here) venue for it.