I know this seems like a basic question, but having searched online, all I can find is information on moving a family into the bin and the posts are from 2005, and don't address if it affects the sim's pregnancy.

Basically my favorite family is about to expand and needs a bigger house, and I'd like to move them instead of destroying their home and having to build a new one on the same lot. If one of the sims in the family is pregnant, can I safely move that family to the bin and subsequently a new home without it affecting the pregnancy? Thank you!

Yes. I do that sort of thing all the time.

The only difficulties that arise with moving pregnant sims arise from merging households. If you decide to move a pregnant sim back in with her birth family, for instance, the game counts the baby when it's calculating whether the merger will work, so if she's carrying twins, or if someone in the household she's going to is pregnant, you may miscount, the total may rise too high and the merger will be refused. This happens when moving from the family bin even with a bigger household mod, but in that case it can be bypassed by moving her onto an empty lot with a telephone and having the family she's to be merged with invite her over and propose a move-in.

Thank you so much! I hadn't been able to find a clear answer on this, it's very much appreciated!