Association of breastfeeding duration with cardiac structure and function in 4 years old

Breast milk is an important source of nutrition for infant development. But few studies have investigated the relationship between breastfeeding duration and children's cardiac structure and function.

To assess the association of the duration of breastfeeding in infancy with cardiac structures and functions in 4-year-old children.

The study analyzed data from 891 mother-offspring pairs in the Shanghai Birth Cohort (SBC) with complete 4-year follow-up and breastfeeding questionnaires. It excluded children with congenital heart defects or missing echocardiography data at age 4. Breastfeeding duration, including exclusive and mixed feeding, was categorized into three groups (<6months, 6-12months, >12months) based on questionnaires at 3 days, 24 days, 6, 12, and 24 months. Echocardiographic data were measured following 2010 American Society of Echocardiography recommendations.

The results showed that: compared to 4-year-old children who were breastfed for less than 6 months, those breastfed for more than 6 months had bigger left atrial and ventricular volume, including increased left atrial diastolic volume [LAVd (β: 2.09, 95% CI: 1.35, 2.83)], left atrial systolic volume [LAVs (β: 0.92, 95% CI: 0.53, 1.3)], left ventricular diastolic volume [LVEDV (β: 2.00, 95% CI: 0.36, 3.62)] and systolic volume [LVESV (β: 0.87, 95% CI: 0.17, 1.57)]. Children breastfed over 12 months showed similar cardiac structural changes as those breastfed 6-12 months. These findings were more pronounced in girls and low birthweight children.

Four-year-old children who were breastfed for six months or more had increased left heart volume, and this association was influenced by gender and birthweight.