Comparison of the risk of microbiological contamination between samples of breast milk obtained at home and at a healthcare facility.

INTRODUCTION Breast milk is the best food for preterm infants. Due to their inadequate suction- swallowing action, the administration of expressed breast milk should be done with an orogastric tube. There is little information available regarding the microbiological safety of expressed breast milk. The aim of this article was to evaluate if there were any differences regarding the contamination of breast milk obtained at a healthcare facility versus at home. METHODS Cross-sectional study that analyzed pairs of breast milk samples (one obtained at home and the other one at a healthcare facility, the same day) from mothers of hospitalized newborn infants with a gestational age =35 weeks. Samples with over 105CFU/mL of mesophilic aerobic bacteria, or with the presence of Escherichia coli, Staphylococcus aureus, Streptococcus faecalis, enterobacterias, Pseudomonas, Salmonella, fungi, and yeast were considered contaminated. RESULTS A total of 280 breast milk samples (140 pairs) from 53 mothers were analyzed; 139 samples (49.6%; 95% CI: 43.6 to 55.6) were contaminated; contamination was significantly more frequent in the samples obtained at home than in those obtained at a healthcare facility (59.6% versus 39.6%; p = 0.0008; OR 2.25; 95% IC: 1.36 to 3.7). CONCLUSION Half of the breast milk samples had bacterial growth, which was more frequent in the samples obtained at home than those obtained at a healthcare facility.