Maternal Vertical Microbial Transmission During Skin-to-Skin Care.

Background: Skin-to-skin (STS) care may contribute to mother-to-infant vertical microbial transmission by enriching the preterm infant's microbiome.

Purpose: The purpose of this observational study was to define the impact of increased STS care duration on vertical microbial transmission and consequently modulate oral and intestinal microbial balance.

Methods: Postpartum women and their preterm infants, 31 to 34 weeks' gestation (n = 25), were recruited for this study. Using 16S rRNA sequencing, we compared α- and β-diversity with the Shannon and Chao indexes and nonmetric multidimensional scaling, respectively, and relative abundance of microbial communities, which refers to the percentage of specific organisms in a community, from mother's chest skin, preterm infant's oral cavity, and preterm infant's stool samples. Effects of STS care on vertical transmission were determined by comparing oral and stool microbial population of preterm infants who received low exposure (<40 minutes) with that of preterm infants who received high exposure (>60 minutes).

Results: Microbial composition, diversity, and relative abundance were different across the 3 sites. Oral microbial richness was less and stool richness was greater among the preterm infants in the high STS care group. Oral and intestinal microbial diversity and composition were different between the groups, with the relative abundance of Gemella and Aggregatibacter genera and Lachnospiraceae family significantly greater in the stool of the high STS care group.

Implications for practice: Results suggest that STS care may be an effective method to enhance microbial communities among preterm infants.