This paper focuses on mother-to-child transmission (MTCT) of the hepatitis B virus (HBV), which is a major public health concern, especially in areas with high HBV endemicity. However, there is vertical transmission from mother to child, which is still a significant source of infection and consequence for the newborn’s health, as they can develop chronic hepatitis B, liver cirrhosis, and hepatocellular carcinoma. Hence, these risks need to be prevented for healthier outcomes for infants born to HBV-infected mothers. The present-day concept of MTCT of HBV, perspectives for further study, and recent achievements in the development of preventive measures, including the employment of antiviral therapy in pregnancy and optimization of immunoprophylaxis, are discussed in this article.
Understanding Mother-to-Child Transmission of HBV
Secondary transmission of MTCT of HBV is mostly through exposure to the mother’s blood and other body fluids, particularly when she is in the process of childbirth. The chance of passing the virus is even higher in mothers with high viral loads and in HBeAg-positive mothers. If not managed, the transmittal rate can hover anywhere between 10% and 90% based on the maternal HBV DNA. 72% of the infants contracting HBV at birth or during the initial years of their life are on the brink of developing the chronic form of hepatitis B disease and therefore require an effective form of prevention.
Standard Immunoprophylaxis
The standard practice for preventing MTCT of HBV includes the intramuscular injections of hepatitis B immunoglobulin (HBIG) and the initial dose of hepatitis B vaccine when the neonate is within 12 hours of birth; the baby’s subsequent doses of the hepatitis B vaccines should be administered at one and six months of age. This regimen has been effective in reducing rates of transmission, as has been evidenced by research findings. However, relapse still exists, especially when the mother has a high HBV DNA level or the immunoprophylaxis regimen is not followed to the later.
The Role of Antiviral Therapy During Pregnancy
Recent investigations have also involved looking at the course of antiviral therapy in pregnancy to decrease maternal HBV DNA, thus decreasing the risk of vertical transmission. Two antiviral drugs, including tenofovir disoproxil fumarate (TDF) and telbivudine, have received some positive findings in clinical studies. ”For example, in a multicenter, double-blind trial, TDF was given to HBeAg-positive pregnant women with high viral load from the 28th week of pregnancy up to 2 months after delivery. In the case of the mothers, the study established a lower concentration of HBV DNA in the maternal serum at the time of delivery as compared to those who received a placebo and a lower incidence of HBV infection in the infants.
Other antiviral drugs, such as telbivudine, also proved to be effective in the prevention of MTCT. Recently, pregnant women with HBV who took telbivudine in the third trimester were found to have lower HBV DNA in the serum at delivery compared with placebo. Thus, telbivudine does not result in chronic HBV infection in infants born to mothers in the telbivudine group; therefore, the compound may be used in combination with the standard immunoprophylaxis.