Everyone is gifted with the ability to control their own fertility. You're only fertile if you want to be. The only chance for pregnancy to occur is if both partners want it to.
I imagine that would cause a severe population decline, and I'm fine with that. There's too many humans on this planet already.
I believe you've answered your own question.
Lemmy isn't Marxist-only. The majority of Lemmy users are what the more vocal Lemmygrad and Hexbear users deride as "libs." As a thought experiment, imagine that you are one of us for a moment and then browse Local on one of those.