Prevalence of pacifier among breastfed and not breastfed infants attending a university hospital ABSTRACTObjective: To evaluate the prevalence of pacifier use in relation to breastfeeding, to find out the reasons why mothers planned or not to introduce this habit and the arguments for changing their minds about the pacifier used.Methods: Cross sectional study comprising 642 motherinfant pairs (0-12months) at a University Hospital, in Campinas, São Paulo, Brazil. The mother was questioned about her original intention regarding the pacifier, the current outcome and the explanation for changing or not her mind. After a descriptive analysis, the logistic regression was applied to verify the association between the pacifier and breastfeeding.Results: The prevalence of pacifier use was 48% (95%CI 44-52), being greater among non-breastfeed infants (70%) compared those breastfed (36%; p=0.029). Among the infants exclusively breastfed, 29% used pacifier (p<0.001). The chance to be breastfed was smaller when the infant used a pacifier (OR=0.22; 95%CI 0.15-0.33). Among the mothers, 60% changed their minds regarding their previous intention about pacifier use. The main reasons for changing plans were: infant rejection (95% -for those who wanted to use the pacifier), and to soothe the baby (72% -for those who initially did not want to use the pacifier). Conclusions:The prevalence of pacifier use is high. This habit is more frequent among non-breastfed infants; among the breastfed ones, it is less frequent for those exclusivelybreastfed. The majority of mothers changed their minds regarding their initial plans about pacifier use. Few worried about the possibility that the pacifier could interfere on breastfeeding.Key-words: pacifiers; breast feeding; weaning. RESUMOObjetivo: Avaliar a prevalência do uso da chupeta em relação ao tipo de aleitamento, as razões das mães para introduzi-la ou não e os fatores associados à mudança de opinião quanto à sua intenção inicial a esse respeito.Métodos: Estudo transversal que avaliou 642 crianças (0-12 meses) atendidas no Hospital da Pontifícia Universidade Católica de Campinas quanto ao tipo de alimentação e uso de chupeta. A mãe foi questionada sobre sua intenção inicial quanto à chupeta, quanto ao seu uso e, se utilizada, porquê. Após análise descritiva, aplicou-se a regressão logística para verificar a associação da chupeta com a amamentação.Resultados: A prevalência de uso de chupeta foi de 48% (IC95% 44-52), sendo maior entre as crianças não amamentadas (70%) comparadas às amamentadas (36%; p=0,029).