Quantitation and evaluation of perinatal medium-chain and long-chain acylcarnitine blood concentrations in 12,000 full-term breastfed newborns

Objectives: Medium-chain (MCA) and long-chain acylcarnitine (LCA) blood concentrations play a significant role in the fatty acid (FA) oxidation process, especially during the first days of life. Identification of their abnormal concentrations, via expanded newborn screening, can lead to the diagnosis of FA oxidation disorders. This study aimed to demonstrate MCA and LCA concentrations in Dried Blood Spots (DBS) of full-term breastfed infants, in relation to their birth weight (BW) perinatally. Methods: Breastfed full-term infants (n = 12,000, 6,000 males, 6,000 females) with BW 2,000-3,999 g were divided into four equal groups: Group A, 2,000-2,499 g, B 2,500-2,999 g, C 3,000-3,499 g, and D 3,500-3,999 g. Samples were collected as DBS and acylcarnitines were determined via a liquid chromatography tandem mass spectrometry method. Results: MCA and LCA blood concentrations were determined significantly lower in group A (low birth weight infants) in both sexes. Infants with BW > 3,500 g (group D), were characterized by lower levels of C10, C10:1, C14, C14:1 acylcarnitines and higher levels of C16 and C18:1 acylcarnitines, as compared to the other groups of this study. Conclusions: Concentration patterns in full-term breastfed newborns in relation to sex and mainly BW found in this study could be very helpful for neonatologists, especially for newborns of group A