Maternal characteristics associated with ovalbumin concentrations in breast milk

BACKGROUND: Breast milk ovalbumin concentrations have been measured with considerable inter-individual variation. Body mass index (BMI) and gestational diabetes mellitus (GDM) in humans, and fish oil supplementation in pigs, have been associated with breast milk protein concentrations. This study aimed to identify whether breast milk ovalbumin concentrations are associated with these maternal characteristics. METHODS: This is a secondary analysis of data collected during a randomized trial. Breast milk ovalbumin concentrations were measured in 66 atopic women 2-6 h after consumption of one egg at 2, 4, and 6 weeks of lactation. Associations between ovalbumin concentrations and maternal characteristics (BMI, GDM and fish oil supplementation during pregnancy) were investigated. RESULTS: Participants with GDM (n = 6) had higher ovalbumin concentrations at 2 weeks of lactation (median = 0.87 IQR 0.27-2.17 ng/mL) compared to participants without GDM (n = 60, median = 0.15 IQR 0.05-0.67 ng/mL; p = .03). Participants who consumed fish oil supplements during pregnancy (n = 16) had higher ovalbumin concentrations at 4 weeks (median = 0.39 IQR 0.07-1.20 ng/mL) and 6 weeks (median = 0.29 IQR 0.15-0.86 ng/mL) compared to those who did not (n = 50, median = 0.05 IQR 0.05-0.44 ng/mL at 4 weeks, p = .01; and 0.05 IQR 0.05-0.40 ng/mL at 6 weeks, p = .01). Pre-pregnancy BMI was not associated with ovalbumin concentrations. CONCLUSIONS: GDM and pregnancy fish oil supplementation were associated with higher breast milk ovalbumin concentrations. Future, larger studies should further investigate associations between these maternal characteristics and breast milk food protein concentrations.