19-29: Maternal Hepatitis B & C Carrier State

A. Hepatitis B Virus

There are an estimated 350 million chronic carriers of hepatitis B virus worldwide (see also Chapter 1). Among these people, there is an increased incidence of chronic active hepatitis, cirrhosis, and hepatocellular carcinoma. In the United States, 1.4 million people are infected, with the highest rate among Asian Americans. All pregnant women should be screened for HBsAg. Transmission of the virus to the baby after delivery is likely if both surface antigen and e antigen are positive. Vertical transmission can be blocked by the immediate postdelivery administration to the newborn of hepatitis B immunoglobulin and hepatitis B vaccine intramuscularly. The vaccine dose is repeated at 1 and 6 months of age. Third trimester administration of tenofovir disoproxil fumarate, 300 mg orally once per day starting at 28–32 weeks and continuing through delivery (first line), lamivudine, or telbivudine to women with a viral load of greater than 10⁶–10⁸ copies/mL has been shown to reduce vertical transmission particularly if the viral load is less than 10⁶ copies/mL at delivery. This therapy appears safe in pregnancy although long-term follow-up data are lacking. Pregnant women with chronic hepatitis B should have liver biochemical tests and viral load testing during the pregnancy. Hepatitis B infection is not a contraindication to breastfeeding, and antiviral therapy if given does not need to be continued postpartum.

B. Hepatitis C Virus

This infection is the most common chronic blood-borne infection in the United States. Risk factors for transmission include blood transfusion, injection drug use, employment in patient care or clinical laboratory work, exposure to a sex partner or household member who has had a history of hepatitis, exposure to multiple sex partners, and low socioeconomic level. The average rate of hepatitis C virus (HCV) infection among infants born to HCV-positive, HIV-negative women is 5–6%. However, the average infection rate increases to 10–11% when mothers are coinfected with HCV and HIV. The principal factor associated with transmission is the presence of HCV RNA in the mother at the time of birth. Treatment is not recommended in pregnancy. Interferon and ribavirin have been considered contraindicated. Ledipasvir/sofosbuvir (Harvoni) has been shown to be safe in animal studies. There is one open-label, phase 1 study of pregnant women with hepatitis C treated with ledipasvir-sofosbuvir for 12 weeks starting in the second trimester. The study only had nine participants, but ledipasvir-sofosbuvir was safe and effective at the standard dose. Larger studies are needed to confirm the findings.