It's a great question.
By way of an overarching answer, I would look at the declaration by the American Public Health Association on the top 100 public health interventions over the past century, from when we came to the year 2000. This is basically from 1900 to 2000. The number one public health intervention across the country—and this was during the time we developed penicillin, vaccines and all of these things—was the introduction of family planning to support the success and engagement of pregnancy-capable people throughout our society.