Hepatitis B and pregnancy

Hepatitis B is a virus that causes inflammation of your liver. If you have hepatitis B during pregnancy, you can pass the virus on to your baby. Vaccinations and treatment after the birth can protect your baby from infection.

Key points

  1. Most women who are carriers of the hepatitis B virus are unaware of this, because often there are no symptoms or only mild symptoms. Read more about hepatitis B and chronic hepatitis B.
  2. You can pass hepatitis B to your baby during the birth through contact with your blood and body fluids. This can happen with vaginal delivery or Caesarean section.
  3. Hepatitis B doesn’t usually cause problems for you or your unborn baby during pregnancy. However, when babies and young children get infected, although they don’t tend to get sick they are at a much higher risk of remaining a hepatitis B carrier and developing ongoing liver problems later in life.
  4. During pregnancy, as part of your antenatal checks when you first see your lead maternity carer, you will be offered a blood test for hepatitis B.

How can I protect my baby from hepatitis B?

During pregnancy, if you test positive for hepatitis B, you will be offered a test that checks the level of hepatitis B virus in your blood. The level of hepatitis B is called the viral load. Without treatment, the higher your viral load, the greater the chance of passing the hepatitis B virus to your baby.

  • If your viral load is high, then the risk of transmission of the hepatitis B virus to your baby is >90%.
  • If your viral load is low, then the risk of transmission of the hepatitis B virus to your baby is between 30–50%.

There are various medicines that can reduce the risk of transmission of the virus to 0% and protect your baby from hepatitis B.

  • All babies born to mothers with hepatitis B will be given hepatitis B vaccine and hepatitis B immunoglobulin soon after delivery. 
  • However, if your viral load is high, you will also be offered treatment with an antiviral medicine called tenofovir to reduce the amount of virus in your body before delivery. 

Tenofovir

Tenofovir tablet is an antiviral medicine. Tenofovir stops the hepatitis B virus multiplying, thereby stopping the virus crossing the placenta to infect your baby. This tablet is taken for the last 8–12 weeks of pregnancy (the third trimester) and is continued for 4–12 weeks after your baby is born. Tenofovir is safe for you and your baby, and you can breastfeed while taking it. Read more about tenofovir.

Hepatitis B vaccine and hepatitis B immunoglobulin

Soon after delivery, your baby will be given 2 injections: a dose of the hepatitis B vaccine and a dose of hepatitis B immunoglobulin. 

  • Your baby will also need the usual hepatitis vaccine at 6 weeks, 3 months and 5 months of age. Read more about the hepatitis B vaccine.
  • At 9 months of age, your baby will be given a blood test to check whether they are protected against hepatitis B or have been infected with the virus. If your baby is not protected, a further 2 doses of the hepatitis B vaccine may be given.

What are the side effects of the vaccine and immunoglobulin?

Like all medicines, hepatitis B vaccine and hepatitis B immunoglobulin can cause side effects, although not everyone gets them. Some of the possible side effects include a mild reaction to the injection such as a rash or a rise in body temperature and, rarely, a severe reaction to the injection.

Is it safe to breastfeed?

Mothers with hepatitis B can breastfeed safely. It’s extremely unlikely that hepatitis B can be passed via breast milk, unless your nipples become cracked and start bleeding. If this happens ask your midwife or doctor for advice.

Learn more

Hepatitis B – information for pregnant women HealthED, Ministry of Health, NZ
Hepatitis B and pregnancy Hepatitis Foundation, NZ

References

  1. Management of hepatitis B in pregnancy RANZCOG, NZ, 2016
  2. Hepatitis B vaccination Newborn Services Clinical Guideline ADHB, NZ, 2015
  3. Hepatitis B – information for pregnant women HealthED, Ministry of Health, NZ
Credits: Health Navigator Editorial Team. Reviewed By: Lucy Mills, Clinical Nurse Specialist, Middlemore Hospital Last reviewed: 27 Aug 2019