I play with aging off, longest seasons available, and mod pregnancy to last at least 3 seasons. I like to keep babies in that stage for at least 4 seasons and toddlers for 12 seasons. I have different saves so I never get bored. One issue I have right now though is a Sim had an affair with the Cottage Living pub owners husband and I have to wait like 6 months irl to find out who the father of her baby is lol.
Edited to add: 2nd trimester in 12 days! >.<
https://i.imgur.com/CeldGIU.png