Prevention of perinatal transmission of hepatitis B virus: the sensitivity, specificity, and predictive value of the recommended screening questions to detect high-risk women in an obstetric population.

The Advisory Committee on Immunization Practices recommends that all pregnant women be questioned concerning risk factors for hepatitis B virus infection and that those giving positive responses be serotested. The sensitivity, specificity, and predictive value of those recommended questions among 692 parturient women were determined. A total of 59 currently or previously infected women (hepatitis B surface antigen (HBsAg), antibody to hepatitis B surface antigen (anti-HBs), or antibody to hepatitis B core antigen (anti-HBc) seropositive) were compared with the 633 seronegative women. Among nonwhite women, the sensitivity of a positive response to any one of the recommended questions was 60%. Specificity and positive predictive value were 71% and 19%, respectively. Among white women, the sensitivity, specificity, and positive predictive value were 56%, 75%, and 11%, respectively. To increase such unacceptably low sensitivity, the authors included two additional questions: single marital status and Medicaid/medical assistance payer status. Sensitivity increased to 96% among nonwhite women and 84% among white women. However, a positive response to at least one of the recommended questions or to additional questions was elicited from 78% of all women (92% nonwhite and 64% white). The authors conclude that to prevent perinatal transmission of hepatitis B, we must serotest all women in our obstetric population.