An estimated four million Americans are infected with hepatitis C, but most are asymptomatic and unaware of their infection. Current treatment options, such as interferon or combinations of interferon and ribavirin, are associated with a positive response in about one half of the patients but have substantial adverse side effects. Over time, up to 90 percent of patients develop chronic hepatitis and, over a period of 20 years, 20 percent develop cirrhosis. An unknown proportion of patients develops hepatic failure or hepatocellular carcinoma. One estimate is that hepatitis C is currently responsible for up to 10,000 deaths per year in the United States, and this could triple over the next 10 to 20 years. If these estimates are accurate, hepatitis C will surpass HIV as a cause of mortality.
In addition to blood-to-blood transmission and sexual contact, hepatitis C can be transmitted vertically from mother to child. This transmission appears to be inefficient, occurring in approximately 5 percent of live births to infected mothers. Factors associated with transmission have not been conclusively identified. Burns and Minkoff reviewed the potential benefit of maternal screening for hepatitis C as a preliminary step in preventing vertical transmission of the virus.
The advantages of screening include the identification of asymptomatic women who might otherwise not present for medical attention until late in the course of the disease, when serious hepatic damage has occurred. These women could be offered therapy and advised to avoid hepatotoxic materials, especially alcohol. Identification of infected mothers would also enable measures to be taken to prevent spread of the virus to household contacts and others, in addition to the unborn child.
Because of the many unknown factors in hepatitis C disease transmission and progression, the Centers for Disease Control and Prevention and the American Academy of Pediatrics currently recommend screening only children born to mothers who are known to have hepatitis C or who have risk factors for the infection. These risk factors include injection of illegal drugs, contaminated blood transfusion, long-term hemodialysis, multiple sexual partners or a sexual partner infected with hepatitis C, and a history of tattooing or body piercing. Routine testing of all pregnant women does not currently appear to be justified (see accompanying table)