How are the criteria of quantity and quality combined in population policies? The fight against "social scourges" in France between 1900 and 1940 is a very interesting case in point, revealing the complexity of the arguments deployed in population policies. Among these scourges, the fight against venereal disease represents an extreme case linked to the representations of sexually transmitted infections. Shameful and therefore unmentionable, these diseases were rarely exposed to public attention, despite concern about depopulation. The questions of population quality and quantity became crystallized around the productivity of marriage. A network of physicians thus took it upon themselves to educate the population about venereal diseases and their adverse effects on the population and the family. The content of this propaganda, notably the anti-venereal films, leaves not doubt as to the role of pro-natalism in health education.