RESUMO
UNLABELLED: Pre-term childbirth is birth before 37 weeks. The incidence in Mexico is approximately between 5 and 10% of all pregnancies and it constitutes one of the primary causes of morbidity and perinatal mortality. OBJECTIVE: To determine the maternal risk factors associated with preterm childbirth in the General Regional Hospital 1 of the Instituto Mexicano del Seguro Social, Querétaro. MATERIAL AND METHODS: A study of cases (A) and controls (B) was made from September 1st, 2001, to June 30th, 2002; group A: 138 patients who finished their pregnancy before the 37th week, group B: 138 patients whose pregnancy came to term. Chi2, Student t test, and the momios method were used for statistical analysis. RESULTS: 8910 obstetric events were attended in the study period of which 600 patients (6.73%) were pre-term. There was no significant statistical difference in the age, the pregnancy interruption process and pre-eclampsia-eclampsia variables. The factors associated with pre-term childbirth with meaningful difference (p < or = 0.05) were weight and maternal height, premature rupture membrane, cervicovaginitis, gravidic hyperemesis, urinary infection, and anemia. CONCLUSION: The incidence of pre-term childbirth as well as its associated factors were similar to those found in literature except for the preeclampsia-eclampsia syndrome.