Hepatitis C virus (HCV) infects from 1 to 4 percent of pregnant women. A woman can become infected by coming into contact with the blood of an infected person. For most women with HCV, this happens during injection of illegal drugs, called injection drug use (IDU). 
The early phase of the infection – the first 6 months – is the acute phase. If you have acute HCV, there is about a 15 to 45 percent chance that your body will fight off the infection and that will be the end of it. But for most people, acute HCV becomes long-term (chronic) HCV. Chronic HCV is a lifetime problem. If you don’t get treatment, chronic HCV can lead to liver disease or liver cancer. The good news is that new HCV drugs can cure chronic HCV for most people. 
HCV and Pregnancy
If you have HCV and you become pregnant, your infection probably won’t get worse. It may even get a bit better. Pregnancy lowers your body’s inflammatory (immune) response, this response is what causes liver damage. The biggest problem with HCV and pregnancy is that you can spread the virus to your baby. This happens in about 6 percent of pregnant women with HCV. There is also some evidence that women with HCV are at higher risk for having babies that are small, underweight, or premature. [1-3]
HCV can spread from a mother to a baby during pregnancy or during delivery when the mothers blood mixes with the baby’s blood. This type of spread is called vertical transmission. If a mother has HIV along with HCV infection, the risk of vertical transmission more than doubles. Babies born with HCV usually have no symptoms and do well during childhood, but the long-term effects are not well known. [1-3]
Should You Be Tested for HCV if You Are Pregnant?
Being pregnant does not increase your risk for HCV. Unless you have certain risk factors for HCV, you don’t need to be tested. You should get tested if you have any of these risk factors: [1,2]
- Any history of IDU
- Any history of snorting illegal drugs (nasal inhalation)
- A history of hemodialysis
- Getting a tattoo at any setting that was not a licensed tattoo parlor
- Having an organ transplant or blood transfusion before 1992
- Receiving a blood transfusion from a person who was later diagnosed with HCV
- Having been in prison
- Having a sexually transmitted disease or HIV
Neither acute or chronic HCV usually cause symptoms. If you do have symptoms, they may include nausea, abdominal pain, fatigue, or jaundice. If you have these symptoms, you may be tested for HCV. 
The first test is a blood test to look for antibodies against HCV. If this test is positive, you may need other blood tests. These tests will help determine if your infection is acute or chronic and the type of HCV you have. There are 6 types, and the type can affect your treatment. You may also have blood tests to check for liver damage and other infections that are common with HCV like sexually transmitted diseases and hepatitis B (HBV). [1,3]
What Happens if You Test Positive for HCV?
In the past, no HCV drugs were safe during pregnancy. Treatment could cause anemia, severe infection, and depression. The drug ribavirin could cause birth defects. Between 2014 and 2016, new HCV medications were developed that are much safer and much more effective. 
These drugs, called direct acting antiviral (DAA) drugs, are not yet approved for pregnancy. They have been shown to be safe in animal studies. Human studies are ongoing. They may be available for pregnant women in the future. For now, the recommendation is to hold off on treatment until after pregnancy and breastfeeding. [1-3]
HCV does not pass through breast milk, so breast feeding is safe if you have HCV. The only caution is if you develop cracked or bleeding nipples. In this case, you could pass the virus to your baby through blood, so you should stop breast feeding until your nipples heal. [1-3]
What Should You Do Now?
If you are diagnosed with HCV infection and you are not pregnancy, you should start treatment with DAA therapy. If you want to become pregnant in the future, this treatment will reduce the chance of passing HCV to your baby. Treatment should be stopped before you start trying to get pregnant. 
If you have not been diagnosed with HCV and you become pregnant, let your doctor know if you have any risk factors for HCV so you can be tested. If you test negative, testing may be repeated later in pregnancy, especially if you continue to be at risk. [1,2]
If you test positive: 
- Have an HCV specialist as part of your pregnancy care team.
- Make sure you do not drink any alcohol. This can increase your risk of liver damage.
- Do not take high doses of the over-the-counter drug acetaminophen (Tylenol). High doses may increase your risk of liver damage. Check with your doctor before starting any new drug, supplement, or herbal medicine.
- Stop breast feeding if your nipples become cracked or bleed.
- Make sure to follow-up with your HCV specialist after pregnancy to start treatment.
- Have your baby tested for HCV after 18 months.
Bottom Line on Pregnancy and HCV
At this time, screening for HCV during pregnancy is only advised for women with risk factors. Treatment for women with HCV during pregnancy is not advised. Although DAA therapy has not been shown to be dangerous, it has not yet been shown to be safe in clinical trials. Since the risk of HCV getting worse during pregnancy is low, and the risk of vertical transmission is low, the risks of treatment during pregnancy are thought to outweigh the risks of waiting. [1-3]
These recommendations may change. Results of a large safety study are due out in 2018.  If it turns out that benefits start to outweigh risks, routine screening and treatment may become the standard of care. [1-3]
- Society for Maternal-Fetal Medicine, Hepatitis C in pregnancy: screening, treatment, and management.
- Infectious Disease Society of America, HCV in Pregnancy.
- CDC, Hepatitis C FAQs for Health Professionals.