Complementary bottles during the first month and risk of cow's milk allergy in breastfed infants

To assess the impact of complementary feeding bottles given at maternity hospital and/or over the first month after discharge from the maternity ward on cow's milk allergy (CMA) risk in breastfed infants.

Case-control study involving infants aged 6-9 months and who were breastfed for at least 1 month.

In 554 cases with a diagnosis of CMA and 211 controls, feeding bottles at maternity hospital, feeding bottles during the first month of life, avoidance of dairy products during pregnancy or breastfeeding, family history of allergy, intake of antibiotics and consumption of proton-pump inhibitors or antacids by the infant during the first month of life were associated with increased risk of CMA in a univariate model. In a multivariate model, only feeding bottle at maternity hospital (OR = 1.81 [1.27; 2.59]), family history of allergy (OR = 2.83 [2.01; 3.99]) and avoidance of dairy products during pregnancy or breastfeeding (OR = 5.62 [1.99; 15.87]) were independent risk factors of CMA.

Complementary bottles given at maternity hospital to newborns who will be exclusively breastfed increases the later risk of CMA. Similarly, avoidance of dairy products during pregnancy or breastfeeding should be discouraged.