What are the implications of Hepatitis B (HBV) infection in pregnancy?

From the Guidelines

Pregnant women should be screened for hepatitis B virus (HBV) infection during each pregnancy, typically in the first trimester, as recommended by the most recent guidelines 1. This approach is crucial because vertical transmission is a major route of HBV infection, and without intervention, 90% of infants born to HBsAg-positive mothers with high viral loads may develop chronic hepatitis B, which can lead to cirrhosis and hepatocellular carcinoma later in life. Some key points to consider in the management of hepatitis B in pregnancy include:

• If a woman tests positive for hepatitis B surface antigen (HBsAg), her newborn should receive both hepatitis B immune globulin (HBIG) and the first dose of hepatitis B vaccine within 12 hours of birth, as stated in the guidelines 1.
• For pregnant women with high viral loads (HBV DNA >200,000 IU/mL or >1 million copies/mL), antiviral therapy with tenofovir disoproxil fumarate (300 mg once daily) is recommended starting at 24-28 weeks of gestation and continuing up to 12 weeks after delivery, according to the latest recommendations 1.
• Women with chronic hepatitis B should be monitored regularly during pregnancy with liver function tests and viral load measurements.
• Breastfeeding is safe for mothers with hepatitis B if the infant has received proper immunoprophylaxis, as supported by the evidence 1.
• Cesarean section is not routinely recommended solely for preventing transmission, unless there are other obstetric indications, as stated in the guidelines 1.

From the FDA Drug Label

Available data from the APR show no increase in the overall risk of major birth defects with first trimester exposure for tenofovir disoproxil fumarate (TDF) (2.1%) compared with the background rate for major birth defects of 2.7% in a U. S. reference population of the Metropolitan Atlanta Congenital Defects Program (MACDP) Published studies in HBV-infected subjects do not report an increased risk of adverse pregnancy-related outcomes with the use of tenofovir disoproxil fumarate during the third trimester of pregnancy In published data from three controlled clinical trials, a total of 327 pregnant women with chronic HBV infection were administered tenofovir disoproxil fumarate from 28 to 32 weeks gestation through 1 to 2 months postpartum and followed for up to 12 months after delivery There were no new safety findings in pregnant women compared with the known safety profile of tenofovir disoproxil fumarate in HBV-infected adults An increased risk of adverse pregnancy-related outcomes was not observed; 2 stillbirths were identified, and there was 1 major birth defect (talipes) and 1 occurrence of multiple congenital abnormalities (not further specified) in tenofovir disoproxil fumarate -exposed infants

Tenofovir disoproxil fumarate can be used in pregnant women with hepatitis B. The data from the Antiretroviral Pregnancy Registry (APR) and published studies show no increased risk of major birth defects or adverse pregnancy-related outcomes with the use of tenofovir disoproxil fumarate during pregnancy, including the third trimester 2.

• Key findings:
  • No increase in overall risk of major birth defects with first trimester exposure
  • No increased risk of adverse pregnancy-related outcomes with use during the third trimester
  • No new safety findings in pregnant women compared to the known safety profile in HBV-infected adults
• Clinical decision: Tenofovir disoproxil fumarate can be used in pregnant women with hepatitis B, with careful monitoring and management by a healthcare provider 2.

From the Research

Hepatitis B in Pregnancy

• Hepatitis B infection in pregnancy can be prevented from being transmitted to the child through antiviral prophylaxis and hepatitis B immunoglobulin (HBIG) administration 3, 4.
• Tenofovir administration in the second or third trimester has been shown to significantly reduce the risk of infant hepatitis B surface antigen seropositivity by 77% when combined with HBIG and the hepatitis B vaccine 3.
• For pregnant women with high hepatitis B virus DNA levels, tenofovir administration in the second or third trimester can prevent mother-to-child transmission when combined with HBIG and the hepatitis B vaccine 3, 4.
• Tenofovir plus HBIG treatment has been shown to result in a rapid HBV DNA load decline in high-risk pregnant women who missed the optimal time window of antiviral prophylaxis 4.

Safety and Efficacy

• Tenofovir administration has been found to be safe and tolerable for both the mother and fetus, with no significant adverse events or congenital malformations reported 3, 4.
• The combination of tenofovir and HBIG has been shown to be effective in preventing recurrent hepatitis B post-liver transplantation, with no significant adverse events reported 5, 6.
• The hepatitis B vaccine has been found to be safe and effective in preventing hepatitis B infection, with a high immunogenicity rate and no significant adverse events reported 7.

Prevention of Mother-to-Child Transmission

• The administration of tenofovir and HBIG in combination with the hepatitis B vaccine has been shown to be effective in preventing mother-to-child transmission of hepatitis B 3, 4.
• The use of tenofovir and HBIG in pregnant women with high hepatitis B virus DNA levels has been found to reduce the risk of mother-to-child transmission by 77% 3.
• The combination of tenofovir and HBIG has been shown to result in a rapid decline in HBV DNA load, reducing the risk of mother-to-child transmission 4.