OBJECTIVES: to evaluate the role of some factors in the genesis of preterm deliveries in Southeast Brazil. METHODS: a cohort hospital-based study of 589 mothers who delivered in Taubaté, a middle-size city in the state of São Paulo, Brazil, between May 1, and October 31, 1999. The statistical approach was Risk Ratio with statistical significance established at alpha: 5%. RESULTS: 70 preterm newborns were identified representing 11,9% of the total birth rate. The variables holding statistical significance were: previous history of stillbirth delivery, smoking during pregnancy, poor weight gain, arterial hypertension, vaginal bleeding, genitourinary tract infection and five or less medical visits for prenatal care. CONCLUSIONS: this study indicates that good quality prenatal care has a great value in preventing preterm births, for poor weight gain, arterial hypertension, vaginal bleeding, genitourinary tract infection and smoking are conditions that can be controlled in the course of pregnancy.
Infant premature; Cohort studies; Risk factors