Hepatitis B infection does not usually cause any problems for you or your unborn baby during pregnancy. It is important for your doctor or midwife to be aware of your hepatitis B infection in order to monitor your health, and so your baby can be protected from infection soon after birth.
If you test positive for hepatitis B, there is still a chance your baby could become infected before birth. If you have very high levels of the hepatitis B virus in your blood, there is still a small chance your baby will become infected while still in the womb (before the immunisations can work). If you test positive for hepatitis B, you should be tested to check whether you have a high level of the hepatitis B virus in the blood, in which case, your doctor or midwife will refer you to see a specialist at the hospital where you may be offered a tablet called tenofovir. This tablet is taken for the last eight to 12 weeks of pregnancy (the third trimester) and is usually stopped four to 12 weeks after your baby is born. It stops the hepatitis B virus multiplying, thereby stopping the virus crossing the placenta to infect your baby. This treatment is safe for you and your baby, and you can breastfeed while taking it.
In order to protect your new baby, your baby must be given two injections soon after delivery. The two injections are:
1. The first dose of the hepatitis B vaccine
2. A dose of hepatitis B immunoglobulin (HBIG).
If these two injections are given within the first 12 hours of birth, your baby has a greater than 95% chance of being protected against hepatitis B infection. However, you must make sure your baby receives the additional doses of hepatitis B vaccine at six weeks, three and five months of age to ensure long-term protection. Your baby should have a blood test at nine months of age to make sure it is fully protected from infection.
Breastfeeding does not increase the risk of mother to baby transmission of hepatitis B. The only situation where breastfeeding may carry a potential risk of transmission is when the mother has cracked or bleeding nipples.
Occasionally (about 1 in 20 cases), the hepatitis B virus can damage your liver during pregnancy. If this damage is very active, this may slow the baby’s growth or make the baby deliver early. If you test positive for hepatitis B, you should be tested to check whether you have a high level of the liver enzymes. If you do, your doctor or midwife will refer you to see a specialist at the hospital who may offer you tenofovir. This is safe to take during pregnancy and while breastfeeding. After you finish breastfeeding, you may be changed to another tablet called entecavir. You will be monitored by either your GP or the hospital.
The Hepatitis Foundation of New Zealand can provide support and information to pregnant women and their families about hepatitis B in pregnancy. For more information contact our free helpline on 0800 33 20 10