Breastfeeding is the recommended infant feeding method by leading health authorities. This recommendation is based on the many health benefits breastfeeding provides to both women and their infants. Breastfeeding rates in Canada, however, are suboptimal, with nearly half of mothers discontinuing exclusive breastfeeding in the first three months and less than twenty-five percent of mothers meeting the recommendation of exclusive breastfeeding to six months.

There are many factors associated with the premature cessation of exclusive breastfeeding. They include demographic, biological, psychosocial, and social factors. Some of these factors are not modifiable, such as age, social status, and education level, as they are not amenable to an intervention. One possible modifiable factor, which may assist women in overcoming breastfeeding difficulties, is fathers' support with breastfeeding. Fathers' favourable attitude and support of breastfeeding positively impacts breastfeeding initiation, duration, and exclusivity. Research on ways to assist fathers in providing support for breastfeeding is needed. The ways in which fathers can provide effective support can best be determined through intervention studies designed to increase fathers' supportive behaviour towards breastfeeding. Specifically, a coparenting framework to guide such interventions would be optimal as coparenting teaches parents to work in partnership towards positive child health outcomes. The purpose of this proposed randomized controlled trial is to evaluate the effects of a coparenting breastfeeding support intervention, delivered to primiparous breastfeeding mothers and the infants' fathers (the breastfeeding woman's male partner, who is jointly responsible for the child). It is hypothesized that this intervention will increase exclusive breastfeeding at 12 weeks postpartum. The secondary outcomes will be breastfeeding duration, perceived breastfeeding support, and coparenting at 6 and 12 weeks. Paternal breastfeeding self-efficacy and infant feeding attitude will be assessed at 6 weeks postpartum.

Participants will include first-time breastfeeding women and the infants' fathers who have singleton births and full term healthy infants. Eligible parents who consent to participate will be randomized into either the intervention group or the control group. The control group will receive standard postpartum care, which is routine care in the hospital and community related to breastfeeding. The intervention group will receive standard postpartum care, plus a multifaceted support intervention that includes: (1) a professional-based in-hospital visit in the first two days postpartum that uses a take-home workbook, breastfeeding booklet, and video, (2) two follow-up emails in the first and third week postpartum, (3) one telephone call to the mother at two weeks, and (4) access to a secure study website for a three month period. All of the components in this intervention will contain extensive information on coparenting and breastfeeding. Follow-up data will be collected by the method chosen by participants, either by web-based survey or telephone interview. This data will be collected by a research assistant blinded to group allocation and data collection points will be at 6 and 12 week postpartum.

The results of this study will be of interest to health care professionals who work with breastfeeding women and their families, as well as policy makers designing programs to meet the needs of childbearing families.