Associations of Umbilical Cord Blood Amino Acid Profiles and Insulin-Like Growth Factor 1 With Birth Weight

Objective To investigate whether umbilical cord blood (UCB) amino acid profiles are affected by newborn birth weight (BW), insulin-like growth factor 1 (IGF-1), and maternal/placental factors. Study Design We conducted a prospective, single-center, observational study using UCBs from 16 light-for-date (LFD) and 61 appropriate-for-dates (AFD) infants. The 20 amino acids in UCBs were measured using liquid chromatography-tandem mass spectrometry. Random forest analysis identified factors influencing the amino acid (AA) profile and BW. Result BW was positively correlated with maternal body mass index and placental weight but not with IGF-1. LFD infants had higher levels of glycine, phenylalanine, methionine, and asparagine than AFD infants. Random forest analysis identified glycine, phenylalanine, asparagine, arginine, and lysine as the top contributors to LFD or AFD. Conclusion Although IGF-1 levels were similar, AA profiles differed from those of AFD infants, suggesting that profiling may identify LFD infants beyond IGF-1 levels.