Trends and determinants in breastfeeding among Korean infants (2007-2021): a nationwide study using the National Health Screening Program for Infants and Children.

Background: Breastfeeding has nutritional, immunolo-gical, and psychological benefits for infants. However, breastfeeding rates have recently declined in South Korea.

Purpose: This study aimed to investigate the breastfeed-ing trends and determinants in a nationwide birth cohort.

Methods: 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 Pro-gram 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 breast-feeding practices.

Results: 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).

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