Trends and determinants in breastfeeding among Korean infants (2007-2021): a nationwide study using the National...

Breastfeeding has nutritional, immunological, and psychological benefits for infants. However, breastfeeding rates have recently declined in South Korea.

This study aimed to investigate the breastfeeding trends and determinants in a nationwide birth cohort.

This retrospective cohort study used claims data from the National Health Insurance Service from 2007-2022. Infants born between 2007 and 2021 who underwent at least one National Health Screening Program for Infants and Children examination were included in this study. Breastfeeding rates were analyzed across eight age-specific sessions, and logistic regression models were used to identify factors associated with breastfeeding practices.

At 4-6 months, the prevalence of breastfeeding decreased from 45.6% in 2007 to 15.4% in 2020, whereas that of formula feeding increased from 36.5% to 70.6%. Similarly, the breastfeeding rate at 9-12 months decreased from 22.7% in 2015 to 12.0% in 2020. In 2021, only 16.6% of neonates were exclusively breastfed at 14-35 days of life, and the rate of exclusive breastfeeding at 6 months further declined from 10.0% in 2020 to 8.8% in 2021. Factors negatively affecting breastfeeding were low birth weight (adjusted odds ratio [aOR], 0.636; 95% confidence interval [CI], 0.607-0.667), preterm birth (aOR, 0.72; 95% CI, 0.687-0.754), multiple births (aOR, 0.603; 95% CI, 0.570-0.638), rural residence (aOR, 0.788; 95% CI, 0.771-0.805), and lower household income (aOR, 0.783; 95% CI, 0.748-0.819) (P<0.001).

Breastfeeding rates in South Korea have declined significantly over the past decade, with disparities observed in preterm, low birth weight, and multiple-birth infants as well as and rural or lower-income households. Targeted interventions including enhanced prenatal education, postnatal support, and community-based initiatives are necessary to improve breastfeeding rates.