title: Vertical transmission of hepatitis C virus: systematic review and meta-analysis.
abstract: BACKGROUND
  We conducted a systematic review of estimates of hepatitis C virus (HCV) vertical transmission risk to update current estimates published more than a decade ago.
  
  
  METHODS
  PubMed and Embase were searched and 109 articles were included. Pooled estimates of risk were generated for children born to HCV antibody-positive and viremic women, aged ≥18 months, separately by maternal human immunodeficiency virus (HIV) coinfection.
  
  
  RESULTS
  Meta-analysis of the risk of vertical HCV infection to children of HCV antibody-positive and RNA-positive women was 5.8% (95% confidence interval [CI], 4.2%-7.8%) for children of HIV-negative women and 10.8% (95% CI, 7.6%-15.2%) for children of HIV-positive women. The adjusted meta-regression model explained 51% of the between-study variation in the 25 included risk estimates. Maternal HIV coinfection was the most important determinant of vertical transmission risk (adjusted odds ratio, 2.56 [95% CI, 1.50-4.43]). Additional methodological (follow-up rate and definition of infection in children) and risk factors independently predicted HCV infection and need to be captured and reported by future studies of vertical transmission. Studies assessing the contribution of nonvertical exposures in early childhood to HCV prevalence among children at risk of vertical transmission are needed.
  
  
  CONCLUSIONS
  More than 1 in every 20 children delivered by HCV chronically infected women are infected, highlighting that vertical transmission likely constitutes the primary transmission route among children. These updated estimates are a basis for decision making in prioritization of research into risk-reducing measures, and inform case management in clinical settings, especially for HIV-positive women in reproductive age.
authors.affiliation: Infectious Disease Epidemiology Group, Weill Cornell Medical College-Qatar, Cornell University, Qatar Foundation-Education City, Doha, Qatar Faculty of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, United Kingdom.
authors.forename: Lenka
authors.initials: L
authors.lastname: Benova
authors.affiliation: Infectious Disease Epidemiology Group, Weill Cornell Medical College-Qatar, Cornell University, Qatar Foundation-Education City, Doha, Qatar.
authors.forename: Yousra A
authors.initials: YA
authors.lastname: Mohamoud
authors.affiliation: Faculty of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, United Kingdom.
authors.forename: Clara
authors.initials: C
authors.lastname: Calvert
authors.affiliation: Infectious Disease Epidemiology Group, Weill Cornell Medical College-Qatar, Cornell University, Qatar Foundation-Education City, Doha, Qatar Department of Healthcare Policy and Research, Weill Cornell Medical College, Cornell University, New York, New York Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, Washington.
authors.forename: Laith J
authors.initials: LJ
authors.lastname: Abu-Raddad
mesh_terms: D000328:Adult; D002675:Child, Preschool; D060085:Coinfection; D005260:Female; D015658:HIV Infections / Q000635:transmission; D006679:HIV Seropositivity; D016174:Hepacivirus / Q000235:genetics / Q000276:immunology; D006526:Hepatitis C / Q000453:epidemiology* / Q000635:transmission*; D006801:Humans; D007223:Infant; D018445:Infectious Disease Transmission, Vertical; D011247:Pregnancy; D012306:Risk; D016036:Seroepidemiologic Studies
keywords: infant; infectious disease transmission; mother-to-child transmission; pregnancy; risk factors