Edinburgh postpartum depression scores are associated with vaginal and gut microbiota in pregnancy

Prenatal and postpartum depression may be influenced by the composition of host associated microbiomes. As such, the objective of this study was to elucidate the relationship between the human gut or vaginal microbiomes in pregnancy with prenatal or postpartum depression. 140 female participants were recruited at their first prenatal visit and completed the Edinburgh Postnatal Depression Scale (EPDS) to screen for depression and anxiety, in addition the EPDS was completed one month postpartum. Vaginal and stool biospecimens were collected in the third trimester, analyzed using 16S rRNA gene sequencing, and assessed for alpha and beta diversity. Individual taxa differences and clustering using the k-medoids algorithm enabled community state type classification. Participants with higher postpartum EPDS scores had higher species richness and lower abundance of L. crispatus in the vaginal microbiota compared to those with lower EPDS scores. Participants with a higher prenatal EPDS score had lower species richness of the gut microbiome. Participants with a vaginal community state type dominated by L. iners had the highest mean prenatal EPDS scores, whereas postpartum EPDS scores were similar regardless of prenatal vaginal state type. Our small sample size and participant's self-report bias limits generalizability of results. Depression in the prenatal and postpartum period is associated with the composition and diversity of the gut and vaginal microbiomes in the third trimester of pregnancy. These results provide a foundational understanding of the microbial relationships between maternal health and depression for identifying potential therapeutic treatments. • High postpartum depression scores associated with a vaginal microbiome with less L. crispatus . • High postpartum depression scores associated with a vaginal microbiome dominated by L. iners . • High prenatal depression scores were associated with a dysbiotic gut microbiome. • Supports importance of the microbiota-gut-brain axis for mental health. • Supports emerging importance of the microbiota-vaginal-brain axis for mental health.