The campaign by the French Eugenics Society for a law requiring a physical examination before marriage was noteworthy in many respects. In the long run it produced the present French marriage law, which is the most obvious legacy of the eugenics movement's efforts to improve the population of France biologically. Although the present law requiring a blood test and tuberculosis x-ray is usually seen as a health measure, it was conceived and implemented in the name of eugenics and grew directly out of the legislation first proposed by Schreiber at the French Eugenics Society conference in 1920. Members of the society were central in proposing, lobbying, and keeping the idea of the premarital examination law before the French public between the wars. No other organization was as actively engaged in promoting the law.

In another sense, the premarital examination law was an important landmark in the history of the French eugenics movement because it represented the first major shift in emphasis of the society from positive to negative eugenics. Although critics argued with the law's effectiveness, there is no question that eugenicists saw the physical examination as part of a screening program whose ultimate purpose was to prevent procreation by the unfit. It is true that this point quickly became obscured (deliberately, one might argue, for political reasons) by related health diagnostic proposals aimed at detecting and treating certain diseases. But, as indicated by the history of the social hygiene movement in Chapter 5, ambiguity was typical of such measures.