Factors associated with the interruption of exclusive breastfeeding in infants up to 30 days old. / Fatores associados à interrupção do aleitamento materno exclusivo em lactentes com até 30 dias.

OBJECTIVE: To identify factors associated with the interruption of exclusive breastfeeding (EBF) in infants up to 30 days old. METHOD: A cross-sectional study conducted at a university hospital in southern Brazil, from December 2014 to September 2015, with 341 infants up to 30 days old and their mothers. A semi-structured questionnaire was applied consisting of variables related to sociodemographic characteristics, obstetric history of the mother, companion's education, and data of the infant and of breastfeeding. Collected data were subjected to bivariate and multivariate analysis with the estimation of Prevalence Ratios (PR). RESULTS: The prevalence of EBF was 79.5%. The factors associated with the interruption of EBF were babies ≥ 21 days, who received formula supplementation at the hospital, women with difficulties breastfeeding after hospital discharge, and non-white. CONCLUSION: the factors associated with EBF interruption can help health workers create actions for mothers with difficulties and prevent interruption of EBF.