Prolonged Exclusive Breastfeeding Duration Is Positively Associated with Risk of Anemia in Infants Aged 12 Months

Detailed breastfeeding information and anthropometric data were obtained for 65,256 children enrolled in the Jiaxing Birth Cohort at 1, 3, and 6 mo of age. Hemoglobin was measured in 25,549 children at 12 mo and in 32,770 children between the ages of 48-71 mo. Anemia was defined as hemoglobin concentrations <110 g/L in children aged <60 mo and <115 g/L in children aged Ã¢â€°Â¥60 mo. The associations between exclusive breastfeeding duration and risk of anemia were assessed as adjusted ORs by using multiple logistic regression. Overall anemia prevalences at 12 and 48-71 mo were 24.9% and 9.9%, respectively. Exclusive breastfeeding for Ã¢â€°Â¥6 mo, but not for 3-5 mo, was significantly associated with a higher risk of anemia in infants at age 12 mo (OR: 1.15; 95% CI: 1.02, 1.29; P = 0.02) compared with exclusive breastfeeding for <3 mo. For young children aged 48-71 mo, this finding was only marginally significant (OR: 1.13; 95% CI: 0.99, 1.29; P = 0.08). Prolonged duration of exclusive breastfeeding was also significantly associated with decreased hemoglobin concentrations of -0.56 g/L (95% CI: -1.10, -0.03; P = 0.04) in infants and -0.99 g/L (95% CI: -1.44, -0.55; P < 0.001) in young children. CONCLUSIONS: Exclusive breastfeeding for Ã¢â€°Â¥6 mo was associated with an increased risk of anemia in infants aged 12 mo and with lower hemoglobin concentrations in both infants aged 12 mo and young children aged 48-71 mo.