Maternal factors and their impact on the placental metabolome

Abstract

Maternal stress during pregnancy has been correlated with adverse maternal and fetal health outcomes. The biological mechanisms underlying stress-linked risk and resilience factors, however, are still not fully understood. The placenta is a vital organ in mediating maternal-fetal interactions, and its function may reflect adaptations to psychological, environmental, and pharmacological exposures by the mother. This thesis includes two complementary studies that utilized nuclear magnetic resonance (NMR) spectroscopy-based metabolomics in conjunction with multivariate and univariate statistical approaches to examine whether distinct prenatal exposures are associated with metabolic signatures in placental tissue. The first study examined maternal prenatal depression (MPD), with or without selective serotonin reuptake inhibitor (SSRI) treatment, and its potential associations with placental metabolic profiles. This study identified unique placental metabolomic patterns associated with MPD without SSRI exposure, whereas placentas from mothers who were depressed and taking SSRIs were not statistically separable from non-depressed and non-SSRI-exposed controls. The second study explored prenatal maternal stress effects on placenta samples from mothers who were exposed to the 2011 Queensland Flood. Objective hardship and subjective distress measures were quantified using validated questionnaires to classify high and low stress groupings. Results indicated no discernable differences between high and low stress groups in either objective or subjective stress categories in placental metabolic profiles. Together, these studies demonstrate the utility of placental metabolomics for examining prenatal psychological, pharmaceutical, and environmental exposures with suggestions for improvement in future research.