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

BACKGROUND

The association between exclusive breastfeeding duration and infant anemia is not clear.

OBJECTIVE

This study aimed to assess the association of exclusive breastfeeding duration with risk of anemia in infants at 12 mo of age and in children aged 48-71 mo in mainland China.

METHODS

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 and 71 mo. Anemia was defined as hemoglobin concentrations <110 g/L in children aged <60 mo and <115 g/L in children aged ≥60 mo. The associations between exclusive breastfeeding duration and risk of anemia were assessed as adjusted ORs by using multiple logistic regression.

RESULTS

Overall anemia prevalences at 12 and 48-71 mo were 24.9% and 9.9%, respectively. Exclusive breastfeeding for ≥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 ≥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. Parents should provide infants with an adequate source of iron after 6 mo of exclusive breastfeeding.