Mother-to-infant transmission of hepatitis C virus.

Mother-to-infant (vertical) transmission of hepatitis C virus (HCV) has been documented but vertical transmission of HCV is less efficient (affecting 0% to 15% [mean 4.7%] of the infants of mothers with HCV infection) than that of hepatitis B virus. This lower rate of vertical transmission is likely due to the lower viral level of HCV in the sera of most mothers with an infection. Infants of mothers with an HCV and HIV coinfection or with a high HCV RNA titre (greater than 1 million copies per millilitre) are at a high risk of HCV infection (with a mean 39% of infants of mothers with HCV and HIV coinfection having an HCV infection). In most infants (81%) with an HCV infection studied longitudinally, the infection is persistent, and the alanine aminotransferase levels are transiently or persistently abnormal; however, normal liver function is also observed in some patients. There is currently no effective way to prevent vertical transmission of HCV. Further investigation aimed at better understanding the natural history of perinatal HCV infection and the indications for antiviral therapy is needed.