Vaginal Seeding and Maternal PPD in a Pakistani Cohort
Abstract:
Background: The postpartum period is a critical window for maternal mental health. Cesarean section (CS) disrupts the vertical transfer of the maternal microbiome and is associated with an increased risk of postpartum depression (PPD). While vaginal seeding is studied for infant microbiome restoration, its impact on the maternal microbiome and her mental health remains entirely unexplored.
Objective: To investigate the effect of vaginal seeding on the maternal gut microbiome and the incidence of PPD in a cohort of Pakistani women undergoing elective CS.
Study Design: A randomized, double-blind, placebo-controlled trial was conducted at Fatima Memorial Hospital. 150 women with term singleton pregnancies scheduled for elective CS were enrolled. Participants were randomized to have their infant and their own hands and face exposed to a gauze containing either maternal vaginal fluid (intervention, n=75) or sterile saline (placebo, n=75). The primary outcome was the change in maternal gut microbiome composition (16S rRNA sequencing) from baseline to 1-month postpartum. The secondary outcome was the score on the Edinburgh Postnatal Depression Scale (EPDS) at 3 months postpartum.
Results: 142 participants completed the study (71 per group). At 1-month postpartum, the intervention group showed a significantly different gut microbiome profile (PERMANOVA, p=0.013) with higher alpha-diversity (Shannon Index, p=0.025) and a greater relative abundance of Lactobacillus (p=0.015). At 3 months, the intervention group had a significantly lower incidence of PPD (EPDS ≥13: 11.3% vs. 29.6%, p=0.008) and a lower mean EPDS score (7.1 ± 3.8 vs. 9.8 ± 4.9, p<0.001). The change in Lactobacillus abundance mediated 32% of the intervention's effect on the EPDS score.
Conclusion: Vaginal seeding is associated with beneficial modulation of the maternal gut microbiome and a significantly reduced risk of PPD. This study is the first to reveal a potential maternal mental health benefit of this practice, positioning it as a dual-benefit intervention for the mother-infant dyad.
