ω9 Monounsaturated and Saturated Colostrum Fatty Acids May Benefit Newborns in General and Subtle Hypothyroid Stages

<b>Objectives:</b> This study analyzed correlations of colostrum fatty acids (FAs), newborns' and mothers' thyroid hormones (THs), and birth weight, all crucially important in neonatal health. <b>Methods:</b> LC-MS/MS was used to measure 22 FAs in the colostrum of 78 healthy mothers who delivered term babies. FT3, FT4, and TSH levels were determined in the mothers' serum, and newborns' TSH was measured in heel-pricked specimens. Correlations were defined in the whole cohort and the subsets, which were separated according to ranges of birth weight, thyroid hormones, and mothers' body mass index. Phyton Software was used for statistics. <b>Results:</b> The colostrum's total FA content was highly variable and correlated positively with the percentage values of arachidic, gondoic, and nervonic acids. Five FAs all positively correlated with birth weight for the entire cohort-including ω9 gondoic, erucic, and nervonic acids as well as saturated behenic and lignoceric acids-all produced with the same elongases. These correlations were relevant to gondoic, nervonic, behenic, and lignoceric acids when mothers with low FT4 levels were evaluated separately and to erucic acid in the subset comprising mothers with high TSH values. <b>Conclusions:</b> The priming of breast epithelia to adjust the colostrum quality starts prenatally, whose regulatory mechanisms partially overlap with fetal fat accretion. Thus, colostrum content may undergo modifications to compensate for the harm of subtle TH deficiencies on neonates' thermoregulation and development. Considering the previous findings showing that milk ω9 FAs are highest in colostrum, and even higher when mothers deliver preterm, our current results indicate their possible protective functions.