Sofosbuvir and ledipasvir (LDV/SOF) are new directly acting antiviral drugs for the treatment of hepatitis C (HCV) that are highly effective, orally administered, well tolerated and preclinical evaluations in animal models indicate safe administration during pregnancy. This project will evaluate the safety and pharmacokinetics of antenatal LDV/SOF treatment for 12 weeks during the second and third trimester. If proven to be effective, antenatal treatment of HCV with LDV/SOF will prevent maternal HCV-related liver disease, perinatal transmission of HCV, and community transmission of HCV.