Viral hepatitis is a condition characterized by inflammation of the liver, caused by a viral infection. Screening for these viruses during pregnancy is a standard part of prenatal care. This proactive testing is important because certain types of viral hepatitis can be passed from a mother to her child (mother-to-child transmission). Identifying the presence of these viruses early allows medical teams to implement interventions that protect the health of both the mother and the baby.
The Standard Prenatal Screening Process
Testing for hepatitis during pregnancy focuses specifically on Hepatitis B Virus (HBV). Screening for HBV is universally recommended for all pregnant individuals, typically conducted during the first trimester at the initial obstetric visit. The method used is a simple blood test that looks for the Hepatitis B surface antigen (HBsAg). A positive HBsAg result indicates the virus is present in the mother’s blood and she has an active infection.
This screening is routinely performed for every pregnancy, even if the mother was previously vaccinated or had a negative result. Performing the test early allows for timely management planning. If a woman is not tested initially or has new risk factors, screening is often repeated upon admission for delivery. This systematic approach ensures the mother’s status is known, allowing infants to receive life-saving interventions immediately after birth.
Assessing Transmission Risk and Maternal Care
Identifying an HBsAg-positive mother requires assessing the risk of Mother-to-Child Transmission (MTCT) and planning maternal care. The highest risk for transmitting HBV occurs during labor and delivery, as the infant is exposed to the mother’s blood and bodily fluids. Without intervention, the infant has a significant chance of acquiring the infection, with a high likelihood of developing a chronic, lifelong HBV infection.
To accurately assess transmission risk, the mother undergoes additional blood testing to determine her viral load. This test measures the amount of Hepatitis B Virus DNA in her blood. A high viral load indicates a greater chance of passing the infection, even if the newborn receives prophylactic treatments.
If the maternal HBV DNA level is greater than 200,000 IU/mL, medical guidelines recommend specific intervention during the pregnancy. Antiviral therapy (AVT) is typically initiated in the third trimester, often between 28 and 32 weeks of gestation. The medication tenofovir is commonly used due to its favorable safety profile. By significantly lowering the mother’s viral load before delivery, this targeted treatment lowers the probability of transmission during birth.
Immediate Newborn Protection Protocols
The most important step in preventing chronic HBV infection in a baby born to an HBsAg-positive mother occurs within the first few hours of life. Two critical interventions are administered to the newborn within 12 hours of birth. The first is a dose of the Hepatitis B vaccine, which stimulates the baby’s own immune system to actively produce protective antibodies.
The second intervention is an injection of Hepatitis B Immune Globulin (HBIG). HBIG is a product made from human blood plasma containing pre-formed antibodies that provides immediate, passive immunity. This neutralizes any virus particles that entered the infant’s body during delivery. This combination of active immunity (vaccine) and passive immunity (HBIG) is highly effective, providing over 90% protection against the baby developing a chronic HBV infection.
This immediate, dual treatment is followed by the completion of the full HBV vaccine series according to the standard immunization schedule. The baby undergoes follow-up serologic testing, usually between 9 and 12 months of age, to confirm successful intervention and immunity.
Targeted Screening for Hepatitis C and A
While Hepatitis B screening is mandatory, testing for Hepatitis C (HCV) is also becoming a standard part of prenatal care. Universal screening for HCV is routinely recommended at the first prenatal visit, using an antibody test to check for exposure. If the antibody test is positive, an additional test for HCV RNA determines if the mother has a current, active infection.
Treatment for HCV is highly effective but is generally deferred until after the baby is born, as the medications have not been extensively studied for safety during pregnancy. Hepatitis A (HAV) screening is not part of the universal prenatal panel. Screening for HAV is only performed using a risk-based approach, such as if the mother has known exposure or presents with symptoms.