By Dr Alex Lampen-Smith, Hepatitis Foundation of New Zealand

World Hepatitis Day, 28 July. 

Hepatitis B is contagious and spreads through bodily fluids, including blood, semen, and vaginal fluids. About 100,000 people in New Zealand have the virus. There are often no symptoms, but the virus can include nausea, tiredness, joint and muscle pain, and jaundice. 

Hepatitis B testing and a vaccination should be offered to the household contacts and sexual partners of people living with hepatitis B. Hepatitis B requires long-term monitoring; six-monthly blood tests are vital.

Since 1987, universal vaccination to protect against Hepatitis B has been available for all children born in New Zealand. Hepatitis B is rare in New Zealanders under 25. 

If I’m pregnant and have hepatitis B, how can it affect my baby?

Occasionally (about one in 20 cases), hepatitis B can damage your liver during pregnancy. If there are high levels of the virus it may slow the baby’s growth or bring on early labour. If you test positive for Hepatitis B, you should be tested to check whether you have a high level of liver enzymes. If you do, your doctor or midwife will refer you to a specialist at the hospital who may offer you tenofovir. This tablet is taken during the third trimester and is usually stopped 4-12 weeks after the birth. It stops the Hepatitis B virus multiplying, so it can’t cross the placenta to infect your baby. Tenofovir is safe to take during pregnancy and while breastfeeding. You will be monitored by your GP or the hospital.

It’s important you tell your doctor or midwife you have Hepatitis B so your baby can be protected from infection immediately after birth. The baby must be given two injections soon after delivery: the first dose of the hepatitis B vaccine and a dose of hepatitis B immunoglobulin. If these two injections are given within the first 12 hours of birth, your baby has a greater-than-95 percent chance of being protected against Hepatitis B. However, it is important your baby also receives the additional doses of Hepatitis B vaccine at six weeks, three and five months of age to ensure long-term protection.

The baby should have a blood test at nine months to make sure it is fully protected from the virus.

Can I breastfeed with Hepatitis B?

Breastfeeding does not increase the risk of mother to baby transmission of Hepatitis B. The only situation where breastfeeding may carry a very low risk of transmission is when the mother has cracked or bleeding nipples. Experts advise that the many benefits of breast-feeding far outweigh any risk.

What if I have Hepatitis B and I want to have a baby?

People with Hepatitis B are 1.59 times more likely to experience infertility than those who don’t. The primary factor in HBV is the S protein (HBs), which lowers sperm motility and reduces the fertilisation rate of sperm by more than half.

Couples need to be educated and counselled regarding the potential risk of transmission to the mother or child. Transmission of viral hepatitis in assisted reproduction is possible, but the magnitude of the risk is unknown.