I think I'm drawing the distinction between "active population control" and "passive population control". I define "active population control" as anything where the goal is to control population and active steps are taken in that direction, typically with the effect of reducing freedom of individuals (e.g. a simple control would be "no more than 2 children per couple", which means an individual cannot decide to have 3 children). Whereas "passive population control" is basically where population growth ends up controlled as a side-effect of other changes, generally without any limits on the freedoms of individuals (for example, eliminating unwanted pregnancies would be a form of passive population control; the goal isn't to control the population but rather to eliminate an undesired situation, and no individual's freedom is curtailed, but the overall effect would be fewer children across the entire population).