Hepatitis B and pregnancy

A woman with hepatitis B can have a normal pregnancy and breastfeed. The main concern is preventing transmission to the newborn. In most cases this can be achieved through diagnosis during pregnancy, antiviral treatment when indicated and protection of the baby immediately after birth.

Transmission occurs mainly around delivery. Without preventive measures, an infected newborn has a very high chance of developing chronic hepatitis B. It is therefore not appropriate to wait for symptoms. Every pregnant woman should know her HBsAg result.

Testing during pregnancy

HBsAg is the initial test for current infection. It should be obtained during every pregnancy, even if the woman has been vaccinated or previously tested negative. A positive result should be confirmed and followed by a complete evaluation.

The assessment includes:

• HBV DNA, or viral load, ideally during the second trimester, to estimate transmission risk.
• ALT and AST and other liver tests.
• HBeAg and other hepatitis B markers when appropriate.
• Tests for hepatitis D, hepatitis C and HIV.
• A clinical assessment to determine whether the mother needs treatment for her own health.

When is treatment recommended during pregnancy?

When the viral load is high, tenofovir disoproxil fumarate (TDF) is recommended during the later part of pregnancy. It lowers the amount of virus in the blood and further reduces transmission risk when added to newborn prophylaxis.

Tenofovir alafenamide (TAF) is a newer formulation that achieves effective concentrations inside cells with lower systemic exposure to tenofovir. Prospective studies and a 2024 meta-analysis indicate that TAF also reduces maternal viral load and achieves prevention rates comparable to TDF, without new maternal or infant safety signals in the available data.

TDF remains the preferred option in most international guidelines because it has longer clinical experience and a larger body of pregnancy safety data. TAF may be considered in selected cases, including women at renal or bone risk or those already taking it to control hepatitis B. A specialist should make this choice after reviewing local approval and availability.

Some women already need treatment because of active hepatitis or fibrosis, independently of pregnancy. They should not stop antiviral treatment without specialist assessment. Abrupt withdrawal can trigger a hepatitis flare.

The timing of treatment and any decision to stop it depend on viral load, liver health and the reason it was prescribed. Liver enzymes are monitored after delivery because a temporary flare can occur.

What should the newborn receive?

An infant born to an HBsAg-positive mother should receive as soon as possible, ideally within the first 12 hours of life:

• The first dose of hepatitis B vaccine.
• Hepatitis B immune globulin, given at a different injection site.

The infant must then complete the vaccine series on schedule. HBsAg and anti-HBs are checked at 9 to 12 months of age, or at least one to two months after the final dose, to confirm that the child was not infected and is protected.

Vaccine and immune globulin should not be delayed while waiting for the mother’s viral load result.

Delivery and breastfeeding

Hepatitis B alone is not a reason for cesarean delivery. The mode of delivery is chosen for obstetric reasons. Mother and baby do not need to be separated.

Breastfeeding is safe when the infant has received appropriate prophylaxis, including when the mother takes tenofovir. If nipples are deeply cracked or bleeding, ask for guidance until they heal.

What about partners and family members?

Sexual partners and household members should have a hepatitis B test panel and receive vaccination if they are not immune. There is no need to separate dishes or avoid hugging. Toothbrushes, razors and other items that may carry blood should not be shared.

With timely coordination among obstetric, liver and pediatric teams, the baby’s risk can be reduced to a very low level.

See also

• Hepatitis B
• Hepatitis B blood tests
• Hepatitis D
• Preventing and detecting hepatitis