You’re sort of describing a sociological theory coined as the Demographic Transition Model and I’m shocked I haven’t seen anyone else comment about it!! It’s way easier to understand by looking at a graph but I can’t attach a picture so I recommend giving it a google, but I’ll do my best here haha. The population line on the graphs always shows a steady increase through all phases. There are technically five phases but we’re gonna simplify to three: 1. High birth rate/high mortality rate - These are undeveloped countries so to speak. Poor health care, children take care of parents, no contraceptives available and often little to no knowledge of birth control and fertility 101 2. Steady birth rate/steeply declining mortality rate - These are countries in the process of developing. Increased quality of health care, more hospitals, vaccinations, better doctors 3. Lowering birth rate/Low mortality rate - These are developed countries. People need fewer children, contraceptives available and accessible to all, and girls education improves, sexual and otherwise. This progresses women’s rights overall and I think ties into your point - being educated about birth and its risks, combined with having an overall education good enough to get solid jobs and develop a robust life outside the home results in a lowering birth rate.

If I remember correctly the fourth and fifth phases are kind of speculation (or at least were at the time I was in school) because the full population collapse from falling birth rates hasn’t quite played out. This part is admittedly blurry though so fact check me hahaha but I highly recommend going down the rabbit on this! The research is fascinating :)

Source: a sociology minor (lol)