Hepatitis B: a case for prenatal screening of all patients.

Evaluation of a mass screening program to detect hepatitis B surface antigen in the obstetric population of Shands Hospital, University of Florida in Gainesville, from January 1, 1983, through December 31, 1985, was undertaken. Prevalence of hepatitis B surface antigen seropositivity was 0.54%. Review of medical records revealed that 67% of patients with positive hepatitis B surface antigen screens had no risk factors identifiable by routine prenatal history. Although all patients were screened on admission to the hospital, the results of the immunoassay were not available in time for staff to institute isolation procedures for the laboring mother or unwashed neonate. In 82% of the cases, treatment of neonates occurred later than 12 hours after delivery (the current Centers for Disease Control recommendation). It is recommended that prenatal screening of all patients with a hepatitis B surface antigen immunoassay be done by 34 weeks' gestation where the patient population is of predominantly low socioeconomic status to ensure appropriate isolation and timely neonatal immunoprophylaxis.