If left undetected and untreated, the virus can cause life-threatening conditions. These can include scarring of the liver (cirrhosis), liver cancer and liver failure. You also will be at a higher risk of contracting HIV and other STIs through unprotected sexual intercourse. There is a risk of transmission from mother to baby either whilst pregnant or during delivery. About one in five people with a chronic Hepatitis C infection will go on to develop cirrhosis of the liver within 20 years.