225 women aged less than 18 years of age at the start of their pregnancies were seen in the Saint Antoine Hospital between July 1977 and December 1983 (1.2%). These pregnancies were studied using data-processing. From the sociological angle there were two main groups. There were on-dwelling French women (29.3%) and African women (27.1%). These groups could be compared according to the total number of women who were married (35% French girls and 95% in the Africans) and the age of the partner and his professional activity. 46 patients had already had one previous pregnancy of which 29 delivered at term. In 25% of the pregnancies there were fewer than 4 antenatal consultations. There was a rise in the numbers of premature labours (22.2%) and only a small number of cases of toxaemia (4.4%). The caesarean section rate was 9.3%. The average weight of the newborn was 3110 g. The perinatal mortality rate was 8 per 1000. The conclusions that can be drawn are that pregnancies in adolescents who attend the Saint Antoine Maternity Hospital are "at risk" pregnancies, but the percentage who are at risk is fewer than in many other countries.