Routine screening for hepatitis B in an obstetric population.

A prospective study was performed to determine whether the Centers for Disease Control (CDC) risk factors for hepatitis B are reliable predictors of the hepatitis B surface antigen carrier state in an obstetric population. At their initial obstetric visit, 1466 consecutive patients had their serum screened for hepatitis B surface antigen by radioimmunoassay. During the initial interview, the physician obtained information regarding the presence of any of the CDC risk factors for hepatitis B (ethnicity or history of venereal disease, blood transfusion, hepatitis exposure, hepatitis, drug abuse, or occupational exposure). Twelve women were found to have positive hepatitis B surface antigen, for a prevalence of 0.82%. Six of these 12 had risk factors. Five had high-risk ethnic background, two of whom also had a history of hepatitis. One health care worker, a nurse, was also positive for hepatitis B surface antigen. The other six patients had no recognized risk factors. If hepatitis B surface antigen had been evaluated according to the CDC risk-factor guidelines, half of hepatitis B surface antigen-positive patients would not have been identified.