title: Hepatitis B surface antigen carrier status and its correlation to gestational hypertension.
abstract: OBJECTIVE
  To determine whether chronic hepatitis B surface antigen (HBsAg) carrier status is associated with an increased incidence of gestational hypertension.
  
  
  METHODS
  A retrospective analysis of all deliveries in a regional obstetric unit over a 4-year period using a comprehensive obstetric database.
  
  
  RESULTS
  The data of 13,792 patients were analysed, of which 1340 (9.71%) were chronic HBsAg carriers. Contrary to our hypothesis, the overall incidence of gestational hypertension was significantly lower in the HBsAg positive group (2.01%) as compared to the negative group (3.58%) (P < 0.01, odds ratio (OR) 0.55, 95% confidence interval (CI) 0.37-0.81). When comparing the incidence of severe preeclampsia, the difference remained significant (0.22 and 0.79%, respectively, P < 0.05, OR 0.28, 95% CI 0.08-0.88). There was otherwise no difference in the incidence of other major obstetric complications between the HBsAg positive and negative groups.
  
  
  CONCLUSIONS
  The findings presented did not support a positive association between HbsAg carrier status and gestational hypertension. The data from the present study, and re-evaluation of similar published data, in fact suggest the contrary observation of a lower than normal incidence of gestational hypertension in HbsAg positive mothers.
authors.affiliation: Department of Obstetrics and Gynaecology, United Christian Hospital, Kowloon, Hong Kong, China. wwkto@hutchcity.com
authors.forename: William W K
authors.initials: WW
authors.lastname: To
authors.forename: Wai
authors.initials: W
authors.lastname: Cheung
authors.forename: Ka-Ming
authors.initials: KM
authors.lastname: Mok
mesh_terms: D000328:Adult; D005260:Female; D006514:Hepatitis B Surface Antigens / Q000032:analysis*; D006801:Humans; D006973:Hypertension / Q000453:epidemiology / Q000276:immunology* / Q000821:virology; D011247:Pregnancy; D011249:Pregnancy Complications, Cardiovascular / Q000453:epidemiology / Q000276:immunology* / Q000821:virology; D012189:Retrospective Studies
chemical_list: D006514:Hepatitis B Surface Antigens