The following is a summary of “Relationship between the maternal vaginal microbiome and the infant gut microbiome by mode of delivery,” published in the FEBRUARY 2023 issue of Obstetrics and Gynecology by Santos S, et al.

For a LEGACY study, researchers sought to determine if there was a correlation between the maternal vaginal microbiome and infant gut microbiome composition and whether delivery mode influenced the relationship.

The study recruited 628 pregnant women, of which 248 delivered vaginally, 224 underwent elective cesarean delivery (C/S), and 156 underwent emergency C/S. Before delivery, maternal vaginal swabs were collected before delivery, and infant stool was collected at 10 days and 3 months postpartum. The samples were subjected to cpn60 universal barcode PCR amplicon sequencing on the Illumina MiSeq platform, followed by taxonomic assignment using a cpn60 database. The data were analyzed using hierarchical clustering, principal components analysis, and differential abundance algorithms.

Lactobacillus or anaerobic species dominated the maternal vaginal microbiomes, while infant stool microbiomes were dominated by enteric species such as Escherichia coli, Bifidobacterium spp., or Klebsiella spp (25 clusters at 10 days; 14 clusters at 3 months). In addition, there were significant differences in the stool microbiome composition of infants at 10 days (PERMANOVA, P<0.01) and 3 months (P<0.05), depending on the mode of delivery. However, the maternal vaginal microbiome composition did not predict the composition of the infant stool microbiome, as there was no significant correlation between them. Instead, the study found that prophylactic antibiotic exposure during delivery significantly impacted the clustering of infant stool microbiomes at 10 days and 3 months.

The results of the LEGACY study indicated that there is no correlation between the maternal vaginal microbiome and infant gut microbiome composition. Furthermore, the differences in infant gut microbiomes observed about delivery mode may be attributed to the use of antibiotics during delivery, which is a major confounding variable.

Reference: ajog.org/article/S0002-9378(22)00996-6/fulltext