title: Maternal group B Streptococcus-related stillbirth: a systematic review.
abstract: BACKGROUND
  Limited epidemiological data on the association between maternal rectovaginal group B Streptococcus (GBS) colonisation and stillbirth makes assessment of antenatal interventions for GBS stillbirth difficult.
  
  
  OBJECTIVE
  To systematically review the existing literature and evaluate the incidence of GBS-related stillbirth by region up to March 2015.
  
  
  METHODS
  A systematic review of the published literature was completed using PubMed/MEDLINE, EMBASE, LILACS, and Cochrane Library, with Medical Subject Headings (MeSH) and search terms based upon the Centers for Disease Control and Prevention's (CDC) Active Bacterial Core Surveillance (ABCs) GBS-related stillbirth definition and chorioamnionitis.
  
  
  METHODS
  Studies reporting original data on GBS-related stillbirth occurring ≥20 weeks of gestation, with GBS confirmed by autopsy or by culture from the placenta, amniotic fluid, or other normally sterile site samples from the stillborn.
  
  
  METHODS
  Descriptive analyses were performed with the absolute GBS-related stillbirth rates and proportion of stillbirths attributed to GBS calculated per study where possible. Differences in stillbirth definitions did not allow for pooled estimates to be calculated.
  
  
  RESULTS
  Seventeen studies reported GBS-related stillbirth rates varying from 0.04 to 0.9 per 1000 births, with the proportion of stillbirths associated with GBS ranging from 0 to 12.1%. Most studies reported data from before the year 2000 and from high-income countries.
  
  
  CONCLUSIONS
  The sparsely available epidemiological evidence was not reported consistently, emphasising the importance of standardised stillbirth definitions and diagnostic methods to optimally assess the effectiveness of any future antenatal interventions. Timing of stillbirth, GBS serotype, and global diversity were gaps in the current evidence.
  
  
  CONCLUSIONS
  Systematic review finds Group B Streptococcus causes up to 12.1% of stillbirths, but more research is needed.
authors.affiliation: Cassandra Nan, Research Consultant, Maastricht, the Netherlands.
authors.forename: C
authors.initials: C
authors.lastname: Nan
authors.affiliation: Medical Research Council: Respiratory and Meningeal Pathogens Research Unit, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.|Department of Science and Technology/National Research Foundation: Vaccine Preventable Diseases, University of the Witwatersrand, Johannesburg, South Africa.
authors.forename: Z
authors.initials: Z
authors.lastname: Dangor
authors.affiliation: Medical Research Council: Respiratory and Meningeal Pathogens Research Unit, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.|Department of Science and Technology/National Research Foundation: Vaccine Preventable Diseases, University of the Witwatersrand, Johannesburg, South Africa.
authors.forename: C L
authors.initials: CL
authors.lastname: Cutland
authors.affiliation: Department of Pediatrics, Baylor College of Medicine, Houston, Texas, USA.
authors.forename: M S
authors.initials: MS
authors.lastname: Edwards
authors.affiliation: Medical Research Council: Respiratory and Meningeal Pathogens Research Unit, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.|Department of Science and Technology/National Research Foundation: Vaccine Preventable Diseases, University of the Witwatersrand, Johannesburg, South Africa.
authors.forename: S A
authors.initials: SA
authors.lastname: Madhi
authors.affiliation: Novartis Vaccines and Diagnostics Ltd, Frimley, UK.
authors.forename: M C
authors.initials: MC
authors.lastname: Cunnington
mesh_terms: D000653:Amniotic Fluid / Q000382:microbiology; D019049:Developed Countries; D003906:Developing Countries; D005260:Female; D006801:Humans; D015994:Incidence; D010920:Placenta / Q000382:microbiology; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000453:epidemiology / Q000382:microbiology*; D050497:Stillbirth / Q000453:epidemiology*; D013290:Streptococcal Infections / Q000453:epidemiology*; D013292:Streptococcus agalactiae
keywords: Group B Streptococcus; guidelines; incidence; perinatal infections; serotype distribution; stillbirth