Anxiety symptoms are frequent during pregnancy, and they adversely affect pregnancy outcomes and offspring development. The underlying biological mechanisms are not known, but may in part be explained by alterations in certain maternal metabolic pathways. No metabolomic studies have investigated possible metabolic alterations in anxious pregnant women.

This pilot study compared the metabolic profiles of anxious and non-anxious pregnant women using a mass spectrometry-based quantitative metabolomics system.

Cases were 20 participants of the Kuopio birth cohort study (www.kubico.fi) with first and third trimester symptoms of anxiety (Edinburgh postnatal depression scale, anxiety subscale – EPDS-3A ≥ 4), but no depression (EPDS ≤ 12). Controls were 20 participants with low anxiety (EPDS–3A ≤ 3) and depression (total EPDS ≤ 9) in both the first and third trimester. Maternal metabolic profiles were analyzed from serum samples drawn when the mothers arrived at the delivery hospital.

Metabolic pathway analyses revealed significant enrichment in the glycine, serine and threonine metabolism (P = 0.046), as well as in the betaine (P = 0.048) metabolism pathways. Homocysteine was the only metabolite to significantly differentiate between cases and controls (VIP score 3.3), with lower concentrations in cases (P = 0.003) even when excluding non-users of folic acid supplementation (n = 5; P = 0.002), C-sections (n = 5; P = 0.013), or samples taken immediately postpartum (n = 2; P = 0.004). No other metabolites significantly differed between the groups.

Physiological adaptation induced by pregnancy, which may have homogenized the study populations, could explain the only minor metabolic differences between the two groups. Further research in larger samples, comparing metabolic alterations in umbilical cord blood and maternal blood is warranted.

The authors have not supplied their declaration of competing interest.