Adding pregnancy in sandbox games is normally a bad idea.
Every reachable scene must be rendered again.
Then all the different outfits, they blow up the work exponentially, and that won't go well for a long time.
Just think of a scene with 3 different girls, that can have 4 different outfits each and be pregnant or not.
That alone would be 24 possibilities to render.
Of course, if you have a strong render rig like a modern threadripper with some RTX2080ti or even Quadro cards and automate this process, it wouldn't be a big problem and some freedom and changes are great, but in doubt I prefer more story/events over another outfit or pregnant versions.
Every reachable scene must be rendered again.
Then all the different outfits, they blow up the work exponentially, and that won't go well for a long time.
Just think of a scene with 3 different girls, that can have 4 different outfits each and be pregnant or not.
That alone would be 24 possibilities to render.
Of course, if you have a strong render rig like a modern threadripper with some RTX2080ti or even Quadro cards and automate this process, it wouldn't be a big problem and some freedom and changes are great, but in doubt I prefer more story/events over another outfit or pregnant versions.