Rapid clearance of bacteria from maternal bloodstream after delivery in pregnancies complicated by pre-labor premature rupture of the membranes.

ABSTRACT: Objective: We investigated whether birth in patients whose pregnancies are complicated by pre-labor premature rupture of the membranes (PPROM) is associated with translocation of microbes in maternal circulation and a systemic inflammatory process. Research Design and Methods: 66 pregnant patients admitted for PPROM [gestational age (GA) median [IQR]: 32±1 weeks] had maternal blood (MB) retrieved prior to birth and within 1-hour post-partum. Immediately after birth, fetal membranes (FM) and placental tissue were frozen in sterile fashion. Bacterial load was assessed by 16S rDNA gene amplification by qPCR. Multiplexed 16S amplicon libraries were sequenced on the Illumina platform and enrichment analysis performed using LfSe and EdgeR. Pro- and anti-inflammatory cytokines were measured in MB using multiplex immunoassay. Histological chorioamnionitis (HCA) and cord blood haptoglobin and IL-6 indicated fetal exposure to antenatal inflammation (Triple I). Results: Bacterial DNA was identified in MB both before and after birth. A significant decrease in MB bacterial DNA was observed within 1-hour post-delivery (p=0.004). Conversely, MB cytokines IL-6 and Il-10 increased significantly (p<0.05 for all) especially in pregnancies exposed to Triple I. Compared to placenta, FM carried a higher bacterial load (p<0.001) regardless of presence or absence of antenatal inflammation. FM had higher bacterial biodiversity with top representation from Mycoplasma spp although Mycoplasma was not found in MB either pre- or post-delivery. While no taxa were systematically enriched in MB post-delivery, sample-by-sample analysis identified three cases where a MB OTU had a match in FM and four cases with a match in placenta. Yet, the most abundant MB OTUs had no match in either tissues. Conclusion: In patients with PPROM, bacterial DNA is present in MB prior to birth but is rapidly removed after delivery in association with a robust immediate postpartum cytokine surge.

ORGANISM(S): human metagenome human blood metagenome

PROVIDER: GSE306804 | GEO | 2025/11/27

REPOSITORIES: GEO