Agree re Stella Browne. My own parents were technically pro contraception but also had one oops after another (as to timing, anyway). I have a bunch of theories about why/how, but who knows if I am right. I think it is relevant that they both came from two-child families themselves, and I have letters my dad wrote as a young man where he's clearly been reading some Jukes/Kallikaks sort of nonsense about dumb people outbreeding smart ones.