Do prenatal affective symptoms have an impact on the infant oral microbial exposure? Results from the Kuopio Birth Cohort Study

BACKGROUND: Up to one-fifth of pregnant women are affected by depression, which has been associated with disruptions in the maternal microbiome during pregnancy. Stress-related disruptions in the maternal vaginal microbiome can be carried over to the offspring, and lead to adverse developmental outcomes. OBJECTIVE: We investigated whether maternal depressive and anxiety symptoms during pregnancy associated with compositional alterations of the oral microbial exposure of infants during vaginal birth. METHODS: We conducted a secondary analysis of 324 mother-newborn pairs participating in the Kuopio Birth Cohort Study in Eastern Finland. Depressive symptoms were measured in the first and the third trimesters of pregnancy using the Edinburgh Postnatal Depressive Scale (EPDS). Bacterial exposure was assessed with 16S rRNA gene amplicon sequencing of oral swab samples collected at birth. The studied microbial features included alpha and beta diversity metrics, as well as the relative abundances of individual taxa characterized at the genus and phylum levels. Linear regression models adjusted for covariates (body mass index, gestational diabetes and use of antibiotics at birth) were constructed with depressive symptoms as the exposure variables and microbial exposure measures as the outcome variables. RESULTS: No statistically significant associations were observed between maternal depressive or anxiety symptoms during pregnancy and alpha or beta diversity metrics of newborn oral microbial exposure at birth. CONCLUSION: Despite existing animal studies and one human study suggesting otherwise, we did not detect any statistically significant associations between maternal depressive symptoms during pregnancy and the composition of newborn oral microbial exposure at birth.