The study found no substantial evidence for a resident placental microbiome in term births. Bacterial presence in the placenta was linked to contamination during delivery, especially in vaginal births, while chorionic villi showed lower bacterial presence than other sampled areas. This challenges previous findings suggesting a consistent placental microbial community.

This work was supported by a PRIDE grant from the hospital-university department "Risks in Pregnancy" and by Paris Descartes university. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. No other conflicts were identified.

This study uses a robust methodology, comparing various placental removal methods, sample areas, and analysis techniques (culture, qPCR, metagenomics). It also carefully considers and controls for contamination. The findings challenge the existence of a consistent placental microbiota and offer an alternative explanation for bacterial presence, significantly contributing to the ongoing debate in this field. Despite some limitations, like the small sample size for metagenomics and limited investigation of contributing factors in vaginal delivery samples, the strengths of the study's methodology justify the rating.