Association between duration of exclusive breastfeeding and nursing mothers' self-efficacy for breastfeeding.

Objective: To verify the association of nursing mothers' self-efficacy for breastfeeding in the immediate postpartum period and six months after birth and obstetric and sociodemographic variables with the duration of exclusive breastfeeding.

Method: Observational, longitudinal, prospective study which followed nursing mothers from the immediate postpartum period to the sixth month postpartum in a municipality in Southern Brazil. For data collection, a questionnaire with sociodemographic and obstetric variables and the scale Breastfeeding Self-Efficacy Scale - short form - were employed in the maternity ward and six months after birth.