Protective Effect of Breastfeeding Against Febrile Seizure: A Nationwide Study in Korea

Background: Breastfeeding is known to protect against febrile seizure (FS). Whether its impact continues throughout the childhood period is still controversial. Our objective was to investigate the protective effect of breastfeeding against FS stratified by age. Methods: We included children who participated in the National Health Screening Program for Infants and Children (NHSPIC) aged between four and six months between 2008 and 2014. Feeding type was confirmed based on the NHSPIC questionnaire, and data from the Korean National Health Insurance Service were used to determine FS cases during a five-year follow-up period. Results: Among the 1,791,335 children, the most prevalent feeding type was exclusive breastfeeding (EB) (42.3%). FS occurred most frequently in the exclusive formula feeding (EF) group (12.2%), followed by the partial breastfeeding (PB) (11.3%) and EB groups (10.7%). Compared with the EF group, the adjusted odds ratio for FS was 0.87 (95% confidence interval, 0.86 to 0.88, P < 0.001) and 0.93 (0.92 to 0.94, P < 0.001) in the EB and PB groups, respectively. The protective effect by age 2.5 years was significant in both the EB (0.85; 0.84 to 0.86, P < 0.001) and PB (0.92; 0.90 to 0.93, P < 0.001) groups. In contrast, the protective effect was not significant in the PB group and inconsistent in the EB group after 2.5 years. Conclusion: Breastfeeding has a protective effect against FS in the most prevalent age period, from 0 to 2.5 years. Despite the limited effect after age 2.5 years, we support the current recommendation for prolonged breastfeeding to promote childhood health. (c) 2022 Elsevier Inc. All rights reserved.