Changes in the relationship over time between marriage and the first child in France are explored. The author first notes that, in the 1970s, the growing practice of modern contraceptive methods led to a decrease in the rate of conceptions outside marriage. However, since 1978, a new increase in ex-nuptial conceptions has occurred, many more of which result in births outside marriage. The links between first births and marriage have also loosened within marriage, as births are now almost as frequent in the two or three years following marriage as in the first year. Differences by socioeconomic and educational status are analyzed.