Inflammatory and haematological markers in the maternal, umbilical cord and infant circulation in histological chorioamnionitis

PLoS One. 2012;7(12):e51836. doi: 10.1371/journal.pone.0051836. Epub 2012 Dec 13.

Abstract

Background: The relationship between histological chorioamnionitis and haematological and biochemical markers in mothers and infants at delivery, and in infants postnatally, is incompletely characterised. These markers are widely used in the diagnosis of maternal and neonatal infection. Our objective was to investigate the effects of histological chorioamnionitis (HCA) on haematological and biochemical inflammatory markers in mothers and infants at delivery, and in infants post-delivery.

Methods: Two hundred and forty seven mothers, delivering 325 infants, were recruited at the only tertiary perinatal centre in Western Australia. Placentae were assessed for evidence of HCA using a semi-quantitative scoring system. Maternal high sensitivity C-reactive protein (hsCRP), procalcitonin, and umbilical cord hsCRP, procalcitonin, white cell count and absolute neutrophil count were measured at delivery. In infants where sepsis was clinically suspected, postnatal CRP, white cell count and absolute neutrophil count were measured up to 48 hours of age. The effect of HCA on maternal, cord and neonatal markers was evaluated by multivariable regression analysis.

Results: The median gestational age was 34 weeks and HCA was present in 26 of 247 (10.5%) placentae. Mothers whose pregnancies were complicated by HCA had higher hsCRP (median 26 (range 2-107) versus 5.6 (0-108) mg/L; P<0.001). Histological chorioamnionitis was associated with higher umbilical cord hsCRP (75(th) percentile 2.91 mg/L (range 0-63.9) versus 75(th) percentile 0 mg/L (0-45.6); P<0.001) and procalcitonin (median 0.293 (range 0.05-27.37) versus median 0.064 (range 0.01-5.24) ug/L; P<0.001), with a sustained increase in neonatal absolute neutrophil count (median 4.5 (0.1-26.4)×10(9)/L versus 3.0 (0.1-17.8)×10(9)/L), and CRP up to 48 hours post-partum (median 10 versus 6.5 mg/L) (P<0.05 for each).

Conclusion: Histological chorioamnionitis is associated with modest systemic inflammation in maternal and cord blood. These systemic changes may increase postnatally, potentially undermining their utility in the diagnosis of early-onset neonatal infection.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Biomarkers
  • C-Reactive Protein / metabolism
  • Calcitonin / blood
  • Calcitonin Gene-Related Peptide
  • Chorioamnionitis / blood*
  • Cross-Sectional Studies
  • Female
  • Fetal Blood / chemistry*
  • Gestational Age
  • Humans
  • Infant
  • Inflammation Mediators / blood*
  • Leukocyte Count
  • Neutrophils
  • Placenta / metabolism
  • Placenta / pathology
  • Pregnancy
  • Protein Precursors / blood

Substances

  • Biomarkers
  • CALCA protein, human
  • Inflammation Mediators
  • Protein Precursors
  • Calcitonin
  • C-Reactive Protein
  • Calcitonin Gene-Related Peptide

Grants and funding

The project was funded by Princess Margaret Hospital Foundation, Women and Infant’s Research Foundation Western Australia, Clive and Vera Ramaciotti Medical Research Foundation, University of Western Australia, Rebecca Cooper Medical Research Foundation, Channel 7 Telethon, European Society for Paediatric Infectious Diseases and the National Health and Medical Research Council Australia (Project grant #572548). TS was supported by a Research Fellowship of the Deutsche Forschungsgemeinschaft (STR1022/1-1) and an International Postgraduate Research Scholarship of the University of Western Australia. DPB is supported by a National Health and Medical Research Council Clinical Career Development Fellowship and the research was supported by the Victorian Government's Operational Infrastructure Support Program. BRAHMS (Thermo Fisher Scientific) provided the procalcitonin assays without charge. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.