title: Caesarean section to prevent transmission of hepatitis B: a meta-analysis.
abstract: BACKGROUND
  Vertical transmission of hepatitis B virus (HBV) occurs in up to 10% to 20% of births.
  
  
  OBJECTIVE
  To assess whether Caesarean section, compared with vaginal delivery, prevents HBV transmission.
  
  
  METHODS
  A systematic review and meta-analysis was conducted. Two investigators independently searched PubMed, EMBASE and other databases for relevant studies published between 1988 and 2013. A manual search of relevant topics and major conferences for abstracts was also conducted. Randomized trials, cohort and case-control studies assessing the effect of delivery mode on vertical transmission of HBV were included. Studies assessing antiviral therapy and patients with coinfection were excluded. The primary outcome was HBV transmission rates according to delivery method.
  
  
  RESULTS
  Of the 430 studies identified, 10 were included. Caesarean section decreased the odds of HBV transmission by 38% compared with vaginal delivery (OR 0.62 [95% CI 0.40 to 0.98]; P=0.04) based on a random-effects model. Significant heterogeneity among studies was found (I²=63%; P=0.003), which was largely explained by variation in hepatitis B immune globulin (HBIG) administration. Meta-regression showed a significant linear association between the percentage of infants receiving HBIG per study and the log OR (P=0.005), with the least benefit observed in studies with 100% HBIG administration. Subgroup analysis of hepatitis B e-antigen-positive women who underwent Caesarean section did not show a significant reduction in vertical transmission.
  
  
  CONCLUSIONS
  Caesarean section may protect against HBV transmission; however, convincing benefit could not be demonstrated due to significant study heterogeneity from variable HBIG administration, highlighting the importance of HBIG in HBV prevention.
  
  
  CONCLUSIONS
  More high-quality studies are needed before any recommendations can be made.
authors.forename: Matthew S
authors.initials: MS
authors.lastname: Chang
authors.forename: Sravanya
authors.initials: S
authors.lastname: Gavini
authors.forename: Priscila C
authors.initials: PC
authors.lastname: Andrade
authors.forename: Julia
authors.initials: J
authors.lastname: McNabb-Baltar
mesh_terms: D002585:Cesarean Section / Q000379:methods*; D036861:Delivery, Obstetric / Q000379:methods; D005260:Female; D006509:Hepatitis B / Q000517:prevention & control* / Q000635:transmission; D006801:Humans; D007136:Immunoglobulins / Q000008:administration & dosage; D007231:Infant, Newborn; D018445:Infectious Disease Transmission, Vertical / Q000517:prevention & control*; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000821:virology
chemical_list: D007136:Immunoglobulins; C045213:hepatitis B hyperimmune globulin