[True primary prevention of premature birth]

The authors are interested in the social differences observed in rates of preterm births. Most of the published studies show a social gradient. Their hypothesis is that these differences are accessible to a simple preventive policy. The propositions are first a better information given to the pregnant women on the risks, and on the relationship of the way of living with uterine contractions and preterm labour and second a reduction in physical efforts, common triggers to uterine pains. The study deals with 11,017 singles pregnancies. It is shown that the social gradient disappears for the women following the program (80% of the pregnancies). The social gradients are those expected for the women followed by other means and referred during pregnancy.