Way back in the Twenties and Thirties, social and biological scientists were looking at fertility rates and noting that the "lesser" ethnic and racial groups reproduced more than the "better" ones. In the words of one respected scientist, "Fertility decreases as one rises the hierarchy of being." (Translation: non-whites reproduce like rabbits because they haven't evolved quite so far away from their animal roots as have whites.)
It was, obviously, a convenient way of marking class, social worth, and intellectual responsibility, as well as encouraging certain behaviors in the respective populations. So, one could encourage immigrants, blacks, and Catholics to reproduce less in order to attain better social status; and one could also encourage limited, planned reproduction among the well off, both so that their "better" genetic stock would be maintained and so that they would not descend into rabbit-like production. The two-child family was both a status marker and a social responsibility.
Today's social scientists are a little more subtle in their efforts to manage reproduction, but there is still a certain social program implicit in various apparently scientific or merely demographic "news" items.
Case in point: The Liberal Baby Bust.
Note the markers of scientific rigor: these comments are based on (cue reverent music) statistics.
Note the lack of even a pretense of charity towards difference: conservatism, patriarchy, Mormonism, and religious fundamentalism are as good as identical, and are highly correlated with high fertility, while progressivism, secularism, feminism, and freedom are all of a piece, and all in danger of extinction-by-reproductive-attrition.
Note the unstated implication: two-children families are once again affirmed to be the most progressive, most intelligent choice.
Foucault was right: the modern nation-state has no need of force. Social programming can be achieved far more effectively and efficiently by the judicious use of a little gentle propaganda.