Enhancing human milk studies: Introducing a less invasive human milk collection technique for the measurement of fatty acids.

Objectives: The fatty acid (FA) supply of human milk (HM) contributes to health outcomes. Sampling fresh HM to analyze its FA content is challenging because of its ever-changing nature. Also, obtaining samples from lactating mothers is challenging. Facilitating HM collection and analysis is therefore an advantage.

Methods: We have conducted a study to validate a new method for obtaining HM samples for FA analysis, using biological fluid sample collection pretreated sheets to adsorb drops of milk (Whatman 903 BHT-pretreated biological fluid collection sheet) as an alternative approach to collecting expressed milk. The study population included lactating mothers, enrolled between 24 and 96 h after delivery.

Results: A total of 124 breastmilk samples were analyzed using the two distinct approaches. The results of the free milk analysis were comparable to the analysis of adsorbed milk samples. The FA families saturated fatty acids (SFA), monounsaturated fatty acids (MUFA), polyunsaturated fatty acids (PUFA), omega-3, and omega-6 had r² values of 0.93, 0.91, 0.91, 0.86, and 0.90, respectively. Bland-Altman plots showed a high agreement between fresh and adsorbed milk samples for SFA, MUFA, PUFA, omega-3, and omega-6 with a mean bias <2% and 95% limits of agreement within -5% and +5%.

Conclusions: The results show no significant differences in fatty acid composition between fresh and adsorbed milk samples, suggesting the new method is equally effective in collecting representative samples for analysis.