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Differing prevalence and diversity of bacterial species in fetal membranes from very preterm and term labor

Hannah E Jones1, Kathryn A Harris, Malika Azizia

  • 1Infectious Diseases and Microbiology Unit, Institute of Child Health, London, United Kingdom. h.jones@ich.ucl.ac.uk

Plos One
|December 10, 2009
PubMed
Abstract

Insights

Bacteria are present in fetal membranes during both preterm and term births. Higher bacterial diversity and spread in preterm births are linked to chorioamnionitis and maternal immune paresis.

Area of Science:

  • Obstetrics and Gynecology
  • Microbiology
  • Immunology

Background:

  • Intrauterine infections are implicated in preterm delivery.
  • Traditional bacterial culturing methods often fail to detect bacteria associated with preterm birth.
  • Molecular techniques offer a more sensitive approach to identify microbial presence.

Purpose of the Study:

  • To identify bacterial DNA in placental and fetal membrane tissues using molecular methods.
  • To compare bacterial prevalence, spread, and diversity in preterm delivery (spontaneous preterm labor and preterm prolonged rupture of membranes) versus term delivery.
  • To investigate the association between bacterial presence and maternal immune response.

Main Methods:

  • Broad-range 16S ribosomal DNA (rDNA) PCR and species-specific, real-time assays were employed.
  • Bacterial DNA was amplified from fetal membranes and placenta of 74 women across different delivery groups (PPROM, PTL, indicated preterm, term).
  • Histological analysis for chorioamnionitis and assessment of maternal blood monocyte immune paresis were performed.

Main Results:

  • Bacterial DNA was detected in fetal membranes of both preterm and term deliveries.
  • Significantly higher bacterial prevalence was observed in spontaneous preterm labor (PTL) and preterm prolonged rupture of membranes (PPROM) groups compared to term vaginal deliveries.
  • Greater bacterial spread and species diversity were found in preterm birth tissues, associated with histological chorioamnionitis and maternal immune paresis.

Conclusions:

  • Bacteria are present in fetal membranes, with increased prevalence and diversity in preterm births.
  • The findings suggest a link between intrauterine bacterial presence, chorioamnionitis, and maternal immune system alterations in preterm delivery.
  • Further research is needed to differentiate between contamination and true intrauterine infection during labor.

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