Neonatal amino acids and acylcarnitines associated with maternal blood glucose levels throughout pregnancy: Insights from the Beijing Birth Cohort Study

Objective: To determine the association between maternal blood glucose patterns throughout pregnancy and neonatal amino acids and acylcarnitines.

Research Design and Methods: We conducted a prospective cohort study involving 11,457 singleton pregnant women without pre-existing diabetes from the Beijing Birth Cohort Study, along with their neonates born between July 2021 and October 2022 in Beijing, China. Distinct maternal glucose trajectories were identified using a latent class model based on blood glucose levels across the three trimesters, and their association with neonatal circulating metabolites, including 11 amino acids and 33 acylcarnitines, was examined, adjusting for potential confounding factors.

Results: Three distinct groups of maternal glucose trajectories were identified: consistent normoglycemia (n = 8,648), mid-to-late gestational hyperglycemia (n = 2,540), and early-onset hyperglycemia (n = 269). Mid-to-late gestational hyperglycemia was associated with decreased levels of amino acids (alanine, arginine, ornithine, and proline) involved in the arginine and proline metabolism, and urea cycle pathway, as well as increased levels of C4DC+C5-OH, and decreased level of C6DC and C10:1. Early-onset hyperglycemia was associated with elevated levels of free acylcarnitine and C4DC+C5-OH and decreased level of C10:1, involved in the fatty acid oxidation pathway. However, these associations were primarily observed in male neonates rather than in female neonates.

Conclusions: Our findings revealed a significant link between maternal glucose trajectories throughout pregnancy and neonatal arginine and proline metabolism, urea cycle pathway, and fatty acid oxidation pathway. These results highlight the importance of maintaining optimal blood glucose levels throughout pregnancy to promote healthy neonatal metabolic outcomes.