Hepatitis C in obstetrics and gynecology.

Because of the risk of perinatal transmission and possible sexual transmission, it is important for obstetrician-gynecologists to keep abreast of the rapidly expanding literature on hepatitis C. Acute hepatitis C represents about 5% of all reported cases of hepatitis. Approximately 50% of acute infections progress to chronic liver disease. Risk factors for infection include intravenous (IV) drug use (21-42% of cases), previous blood transfusion (6-17%), and multiple sexual partners (6%); 40-50% of cases have no identified risk factors. The seroprevalence of anti-hepatitis C antibody is 70.8% in IV drug users, 11.6% in patients with human immunodeficiency virus, 8.8% in prostitutes, 1.2% in hospital personnel, and 0.5-1.4% in volunteer blood donors. The risk of transmission to the neonate depends on the trimester at exposure. No perinatal transmission has been shown after acute maternal infection in the second trimester. Based on the few reported cases, chronic maternal infection or acute infection in the third trimester may result in neonatal infection rates of 45-87.5%. Universal screening is probably not cost-effective because the prevalence is low and over 70% of screening tests can be falsely positive using the currently approved assay. Selective screening of high-risk patients is recommended.