Breast milk is nutritionally adequate and is related to the reduction of various health problems in childhood. Its offer is widely recommended in health guidelines.

To estimate the prevalence and obstacles to breastfeeding in patients with CHD in southern Brazil.

Cross-sectional study of patients with CHD between 2 and 18 years of age. Patients with genetic syndromes and patients whose mothers had died were excluded from the analysis. The variables on breastfeeding in the first 2 years of life were collected through a phone call to the mothers, which was conducted by trained evaluators. Prevalence was described in proportions and the continuous variables as means and standard deviation. Bivariate analyses were evaluated using a chi-square test to measure the association between the variables and the outcome.

A total of 351 patients with CHD were analysed. There was a predominance of males (53%) and a mean age of 9.54 ± 4.52 years. Breastfeeding up to the sixth month was present in 40% of the cases.

The mothers of babies with CHD face great challenges to maintain the supply of breast milk, whether inherent to the practice of breastfeeding or related to CHD.