To identify risk factors related to maternal ethnic origin. Retrospective review of 5808 cases of French, Maghrebian and Black African women who delivered between 1988 and 1994 at the Maternity of La Grave Hospital in Toulouse. Pathological pregnancies were more frequent (60% vs 45%), specifically anemia OR = 10.2[6.3-16.7] and OR = 5.7[4.0-8.3]) and genital infections (OR = 1.7[1.2-2.6] and OR = 1.7[1.4-2.1]) in African and Maghrebian respectively. than in French women. These differences cannot be referred to any classical risk factors but only to the mother's ethnic origin. Moreover, cesarean delivery occurred almost twice as much in African women 34% vs 19%) and no specific medical indication was found to explain this increase. Our data concluded that important risk factors were related to the mother's ethnic origin. This finding demonstrates that management of perinatal care and epidemiologic studies should take maternal ethnic origin into account.