ABSTRACT. Background. Despite growing evidence of the benefits of prolonged breastfeeding for mother and infant health, the rate of breastfeeding at infant age of 6 months remains below the Healthy People 2010 goal. The greatest decrease in the breastfeeding rate occurs during the first 4 postpartum weeks. Mothers who discontinue breastfeeding early are more likely to report lack of confidence in their ability to breastfeed, problems with the infant latching or suckling, and lack of individualized encouragement from their clinicians in the early postdischarge period. Observational studies suggest that primary care physicians can increase breastfeeding rates through specific advice and practices during routine preventive visits. However, robust scientific evidence based on randomized, controlled trials is currently lacking.Objective. The purpose of this study was to determine whether attending an early, routine, preventive, outpatient visit delivered in a primary care physician's office would improve breastfeeding outcomes.Design. The study was a prospective, randomized, parallel-group, open trial.Setting. Participants were recruited at a level 3 maternity facility, with an average of 2000 births per year, in France.Participants. A total of 231 mothers who had delivered a healthy singleton infant (gestational age: >37 completed weeks) and were breastfeeding on the day of discharge were recruited and randomized (116 were assigned to the intervention group and 115 to the control group) between October 1, 2001, and May 31, 2002; 226 mother-infant pairs (112 in the intervention group and 114 in the control group) contributed data on outcomes.Intervention. Support for breastfeeding in the control group included the usual verbal encouragement provided by the maternity ward staff members, a general health assessment and an evaluation for evidence of successful breastfeeding behavior by the pediatrician working in the obstetrics department on the day of discharge, provision of the telephone number of a peer support group, mandatory routine, preventive, outpatient visits at 1, 2, 3, 4, 5, and 6 months of infant age, and 10 weeks of paid maternity leave (extended to 18 weeks after the birth of the third child). In addition to the usual predischarge and postdischarge support, the mothers in the intervention group were invited to attend an individual, routine, preventive, outpatient visit in the office of 1 of the 17 participating primary care physicians (pediatricians or family physicians) within 2 weeks after the birth. The participating physicians received a 5-hour training program on breastfeeding, delivered in 2 parts in 1 month, before the beginning of the study.Outcome Measures. The primary outcome was the prevalence of exclusive breastfeeding reported at 4 weeks (defined as giving maternal milk as the only food source, with no other foods or liquids, other than vitamins or medications, being given). The secondary outcomes included any breastfeeding reported at 4 weeks, breastfeeding duration, breastfeeding difficulti...