title: Vertical transmission of hepatitis B virus during pregnancy and delivery in Denmark.
abstract: OBJECTIVE
  In Denmark, pregnant women have been screened for hepatitis B virus (HBV) since 2005, and children born to HBV-infected mothers offered hepatitis B immunoglobulin at birth, vaccination against HBV at birth and after 1, 2 and 12 months. The purpose of this study was to determine the risk of vertical HBV transmission in children born to mothers with chronic HBV infection, to investigate the antibody response in the children and to investigate possible maternal predictive risk factors for HBV transmission.
  
  
  METHODS
  Through the Danish Database for Hepatitis B and C, we identified 589 HBV-infected women who had given birth to 686 children, of whom 370 children were born to 322 women referred to hospital. 132 (36%) children, born to 109 mothers, were included in the study; 128 children had blood samples tested for HBsAg, anti-HBc (total), anti-HBs and HBV-DNA and four children had saliva samples tested for anti-HBc.
  
  
  RESULTS
  We found vertical HBV transmission in Denmark to be 2.3% [95% CI: 0.5, 6.5], a high proportion of HBsAg-negative children with low levels of anti-HBs (18.4%) and a high proportion (15.2%) with resolved HBV infection. No maternal risk factor was statistically significantly associated with HBV vertical transmission.
  
  
  CONCLUSIONS
  In a HBV low prevalence setting as Denmark, despite a national vaccination program, vertical HBV transmission occurred in 2.3% of children born to HBV-infected mothers. In addition, a high proportion of the children had insufficient anti-HBs levels and a high proportion had serological signs of resolved HBV infection.
authors: a Department of Infectious Diseases , Copenhagen University Hospital , Hvidovre , Denmark.|b Department of Clinical Medicine, Faculty of Health and Medical Sciences , University of Copenhagen , Copenhagen , Denmark.
authors: Nina
authors: N
authors: Weis
authors: c Department of Epidemiology , Statens Serum Institut , Copenhagen , Denmark.
authors: Susan
authors: S
authors: Cowan
authors: a Department of Infectious Diseases , Copenhagen University Hospital , Hvidovre , Denmark.
authors: Sofie
authors: S
authors: Hallager
authors: d Department of Infectious Diseases , Odense University Hospital , Odense, Denmark.
authors: Sandra
authors: S
authors: Dröse
authors: e Department of Medicine , The Region Hospital , Viborg , Denmark.
authors: Lena Hagelskjær
authors: LH
authors: Kristensen
authors: f Department of Gastroenterology , Copenhagen University Hospital , Hvidovre , Denmark.
authors: Karin
authors: K
authors: Grønbæk
authors: g Department of Medicine , Kolding Hospital , Denmark.
authors: Janne
authors: J
authors: Jensen
authors: h Department of Infectious Diseases , Copenhagen University Hospital , Rigshospitalet , Denmark.
authors: Jan
authors: J
authors: Gerstoft
authors: i Department of Medicine , Køge Hospital , Køge , Denmark.
authors: Lone G
authors: LG
authors: Madsen
authors: j Department of Hepatology , Copenhagen University Hospital , Rigshospitalet , Denmark.
authors: Mette Rye
authors: MR
authors: Clausen
authors: k Department of Infectious Diseases , Nordsjællands Hospital , Hillerød , Denmark.
authors: Suzanne
authors: S
authors: Lunding
authors: l Diagnostic Center , Silkeborg Regional Hospital , Silkeborg , Denmark.
authors: Britta D
authors: BD
authors: Tarp
authors: m Department of Infectious Diseases , Roskilde Hospital , Roskilde, Denmark.
authors: Toke S
authors: TS
authors: Barfod
authors: n Department of Gastroenterology , Medical Section, Copenhagen University Hospital , Herlev , Denmark.
authors: Stine
authors: S
authors: Sloth
authors: o Department of Clinical Immunology , Odense University Hospital , Odense , Denmark.
authors: Dorte Kinggaard
authors: DK
authors: Holm
authors: a Department of Infectious Diseases , Copenhagen University Hospital , Hvidovre , Denmark.
authors: Jesper
authors: J
authors: Jensen
authors: p Section of Molecular Diagnostics, Clinical Biochemistry and Department of Medical Gastroenterology , Aalborg University Hospital , Aalborg , Denmark.
authors: Henrik
authors: H
authors: Krarup
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D004279:DNA, Viral / Q000097:blood; D016208:Databases, Factual; D003718:Denmark; D005260:Female; D006510:Hepatitis B Antibodies / Q000097:blood; D006511:Hepatitis B Antigens / Q000097:blood; D006515:Hepatitis B virus; D019694:Hepatitis B, Chronic / Q000453:epidemiology / Q000635:transmission*; D006801:Humans; D007223:Infant; D018445:Infectious Disease Transmission, Vertical / Q000517:prevention & control / Q000706:statistics & numerical data*; D016015:Logistic Models; D008297:Male; D008403:Mass Screening / Q000379:methods; D011247:Pregnancy; D012307:Risk Factors; D014611:Vaccination / Q000706:statistics & numerical data*; D055815:Young Adult
chemical_list: D004279:DNA, Viral; D006510:Hepatitis B Antibodies; D006511:Hepatitis B Antigens
keywords: Hepatitis-viral; antibody response; hepatitis B virus infection; mother to child transmission; nationwide; resolved hepatitis B virus infection; vaccine; vertical transmission