Infected amniotic membranes, called chorioamnionitis, can cause fetal infection as a consequence of proximity. A retrospective cross–sectional study, 274 preterm infants born within a year were analyzed and placentas from each preterm infant were classified as positive or negative chorioamnionitis and in the records of preterm infants, those with early neonatal sepsis, perinatal asphyxia, respiratory failure, clinical and / or laboratory changes within the first 72 hours of life. The data showed that there was greater morbidity and mortality in preterm infants with positive chorioamnionitis.