Breastfeeding provides numerous benefits to infants, mothers, and society. Exclusive breastfeeding (EBF) can improve these benefits and is recommended for the first six months of life. Various promotion efforts have improved breastfeeding initiation rates, however, EBF rate at six months, is still well below the goal of Healthy People 2010. Theory-based research is needed to investigate factors associated with mothers’ decisions to continue EBF for 6 months so that appropriate interventions are designed.

A study was conducted to understand psychosocial factors underlying the continued EBF behavior for six months among mothers who have initiated EBF using the framework of the Theory of Planned Behavior. A Breastfeeding Questionnaire was developed from formative research using an elicitation procedure. The scale was self-administered to a cohort of volunteer mothers (N=78) who were < 3 months postpartum and had initiated EBF, to measure theoretical constructs of the theory. Telephone interviews were conducted at 6 months postpartum to measure actual duration of EBF.

The proportion of mothers who showed a strong intention to EBF for six months was 47.4% at baseline. Only 22.2% of mothers performed the behavior. Reasons for termination of EBF before six months were circumstances that mothers encountered after they progressed with EBF. Early introduction to solid foods prompted by the baby was the foremost reason that resulted in early termination of EBF.

The correlation between intention and the behavior of continuation of EBF for six months was significant (γ=0.67, p< .01). Multiple regression analysis showed that attitude toward the act, subjective norm, and perceived behavioral control accounted for 50.2% (p< .01) of the total variance of intention. Addition of self-efficacy to the model improved the accountability (4.4% improvement, p< .01). The subjective norm was the most influential in predicting intention. Findings of this research provide guidelines for future breastfeeding education programs. On-going lactation support to improve knowledge and skills may be effective to increase self-efficacy. Promotion efforts that encourage participation of the mother’s social network may also be effective to improving the mother’s intention. As breastfeeding promotions move the societal norm to EBF for six months, mothers will no longer consider EBF as a matter of choice.