Breastfeeding practice, breastfeeding policy and hospitalisations for infectious diseases in early and later childhood: a register-based study in Uppsala County, Sweden

OBJECTIVE: To examine the association between breastfeeding practice and hospitalisations for infectious diseases in early and later childhood, in particular, to compare exclusive breast feeding 4–5 months with exclusive breastfeeding 6 months or more. Thereby, provide evidence to inform breastfeeding policy. DESIGN: A register-based cohort study. SETTING: A cohort was created by combining the Swedish Medical Birth Register, the National Inpatient Register, the Cause of Death Register, the Total Population Register, the Longitudinal integration database for health insurance and labour market studies, with the Uppsala Preventive Child Health Care database. PATIENTS: 37 825 term and post-term singletons born to women who resided in Uppsala County (Sweden) between 1998 and 2010. MAIN OUTCOME MEASURES: Number of hospitalisations for infectious diseases in early (<2 years) and later childhood (2–4 years). RESULTS: The risk of hospitalisations for infectious diseases decreased with duration of exclusive breastfeeding until 4 months of age. In early childhood, breast feeding was associated with a decreased risk of enteric and respiratory infections. In comparison with exclusive breast feeding 6 months or more, the strongest association was found between no breastfeeding and enteric infections (adjusted incidence rate ratios, aIRR 3.32 (95% CI 2.14 to 5.14)). In later childhood, breast feeding was associated with a lower risk of respiratory infections. In comparison with children exclusively breastfed 6 months or more, the highest risk was found in children who were not breastfed (aIRR 2.53 (95% CI 1.51 to 4.24)). The risk of hospitalisations for infectious diseases was comparable in children exclusively breastfed 4–5 months and children exclusively breastfed 6 months or more. CONCLUSIONS: Our results support breastfeeding guidelines that recommend exclusive breastfeeding for at least 4 months.