Both the American Academy of Pediatrics (AAP) and the Institute of Medicine (IOM) recommend delaying the introduction of cow’s milk until after 1 year of age due to its low absorbable iron content. We used a novel computerized decision support system to gather data from multiple general pediatrics offices. We asked families whether their child received cow’s milk before one year of age, had a low iron diet, or used low iron formula. Then, at subsequent visits, we performed a modified developmental assessment using the Denver II. We assessed the effect of early cow’s milk or a low iron diet on the later failure of achieving developmental milestones. We controlled for covariates using logistic regression. Early cow’s milk introduction (OR 1.30, p = 0.012), as well as a low iron diet or low iron formula (OR 1.42, p < 0.001), were associated with increased rates of milestone failure. Only personal-social milestones (OR 1.44, p = 0.002) showed a significantly higher rate of milestone failure. Both personal-social (OR 1.42, p < 0.001) and language (OR 1.22, p = 0.009) showed higher rates of failure in children with a low iron diet.
Conclusions
There is an association between the introduction of cow’s milk before one year of age and the rate of delayed developmental milestones after one year of age. This adds strength to the recommendations from the AAP and IOM to delay cow’s milk introduction until after one year of age.