Currently there is no preventative measures to prevent transmission of hep C. There are Vaccines for Hep A and Hep B.
Here is a link for FAQ about Hep C from the CDC
Hep c is not considered to be an STD and the CDC does not recommend long term monogamous couples need to use barrier protection.
However this advice does not apply to everyone and there are many illnesses in the world that are sexually transmitted so the recommendation for everyone who is not in a long term monogamous relationship is to use barrier protection to protect you from everything out there.
HepC is a lot harder to get than HIV, I have been married 30 years, my husband never got it. There are a lot of people on this site who have had long term relationships where the partner is virus free. The best prevention is to be smart and don't do high risk behaviors together, i.e. iv drugs. It is only passed blood to blood.
P.S., I didn't know I had HCV for 29 of those years, and I am sure I had it before I ever met my husband. My daughter didn't get it from me either. It would be wonderful if there was a medication that could protect unborn children from getting it, even though that is even a very small percentage.
Unfortunately we do not have a pill or a vaccine to prevent HCV infection. The best means of protection is barrier protection between secual partners. although in long term monogamous relationships, the transmission rate is less than 2%. The more sexual partners a person has had, along with any STI's increases the risk of transmission.
By the way, injection drug users have a much higher chance of acquiring HCV than HIV. However, HIV and Hep B are much more easily transmitted sexually than HCV.