Mexican infants primarily breastfed from 0–6 months are protected against gastrointestinal infections but may have low iron stores at six months.

Abstract

Although the benefits of breast-feeding are beyond doubt, ensuring adequate iron status of breast-fed infants is a concern. We undertook a prospective study in Guadalajara, Mexico to examine the relationship between infant feeding and growth, cumulative incidence of infection, and iron stores. We followed for six months 158 healthy-term infants born to low-income women. Monthly, weight and length were measured, and mothers reported symptoms of infant illness and feeding method. Iron stores were assessed at six months utilizing serum ferritin. Infants were grouped according to feeding mode during 0–4 months, with 38% of infants primarily breastfed (BF), 27% partially breastfed (PBF), and 35% formula fed (FF). No differences were observed among feeding groups in attained weight and length or cumulative incidence of upper respiratory infections. At six months, BF infants had 1.9 times lower and PBF infants had 1.4 times lower ferritin than did FF infants. During 0–6 months, BF infants were less likely to have a gastrointestinal infection (GI) (20%) versus not BF infants (PBF, FF combined) (34%, p<.05). Thus, BF infants had protection against GI during early infancy, but reduced iron stores at six months of age. BF infants may be at increased risk for iron deficiency in the second half of infancy, a common problem in Mexico, if iron-rich complementary foods are not used beginning around six months. Study funded by University of Alberta International, Dr. Willows, and Juan I Menchaca Hospital.