Impact of maternal anemia during pregnancy on neonatal metabolic profiles: evidence from the Beijing Birth Cohort Study.

BACKGROUND

Anemia during pregnancy is associated with various adverse neonatal outcomes. However, the association between maternal anemia during pregnancy and newborn metabolic profiles remains unclear. This study aimed to investigate whether anemia during pregnancy is associated with alterations in neonatal metabolic profiles.

METHODS

This prospective observational cohort study included 12,116 pregnant women, with or without gestational anemia, recruited through the Beijing Birth Cohort Study (ChiCTR2200058395), along with their neonates born between July 2021 and October 2022 in Beijing, China.

RESULTS

Among the 12,116 participants, 576 pregnant women were diagnosed with anemia (Anemia group), while 11,540 did not have anemia (Control group). The rates of metabolic profile abnormalities were significantly higher in the Anemia group compared to the Control group (P < 0.05): 20.83% vs. 16.1% for the overall metabolic profile, 11.9% vs. 9.25% for amino acid profiles, and 11.11% vs. 8.04% for acylcarnitine profiles. Individual metabolic indicators showed significant differences: alanine and arginine levels significantly decreased, while tyrosine levels significantly increased in the Anemia group. Notably, most acylcarnitines indicators (C0, C2, C4DC + C5-OH, C5DC + C6-OH, C6, C6DC, C10, C10:1, C12, C12:1, C14, C14:1, C14:2, C16, C16:1, C16:1-OH, C18, and C18:1) were significantly reduced in the Anemia group, except for C5, which was elevated. Pathway analysis revealed that these alterations were associated with beta-oxidation of very long-chain fatty acids, oxidation of branched-chain fatty acids, mitochondrial beta-oxidation of long-chain saturated fatty acids, and fatty acid metabolism. All of these pathways were related to fatty acid oxidation. Sensitive analyses in normal birth weight (NBW) and term infants (TI) confirmed these findings and demonstrated their robustness. In addition, in NBW infants and TIs, citrulline and arginine were significantly decreased, which were associated with aspartate metabolism and the urea cycle.

CONCLUSIONS

Maternal anemia during pregnancy is significantly associated with alterations in neonatal metabolic profiles, particularly in fatty acid beta-oxidation and related pathways. These findings highlight the potential metabolic consequences of gestational anemia and provide insights into its role in adverse neonatal outcomes and abnormal newborn screening results.