Vaccination against the hepatitis B virus is an important way to prevent chronic hepatitis. If you are pregnant and not immune to hepatitis B, the hep B vaccine can protect you and your unborn baby.

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Hepatitis B virus (HBV) infection is extremely common. About 296 million people worldwide are currently HBV-positive, and 0.7–0.9% of pregnant women in the United States have chronic HBV.

HBV is harmful and easily contracted via exposure to the blood or bodily fluids of someone who has the virus. If you have not been vaccinated and you have HBV, you are very likely to transmit the infection to your baby

Universal childhood vaccination against HBV, which was introduced in 1991, has reduced the number of reported HBV infections by 90%. Universal prenatal testing for HBV, treatment for birthing parents who have HBV, and preventive care (prophylaxis) for their newborns can all help prevent birth-related transmission of HBV.

However, some U.S. adults may not have received their complete hepatitis B (hep B) vaccine series, possibly due to incomplete records, prior parental refusal, or birth outside the United States. If you haven’t yet received the complete hep B vaccine series, the Centers for Disease Control and Prevention (CDC) recommends that you get it now.

If you’re planning to conceive or already pregnant, the hep B vaccine is considered a safe option that can help protect you and your unborn baby.

Yes. If you’re pregnant and are not immune to hepatitis B, get the vaccine. The CDC recommends hep B vaccination for all previously unvaccinated adults ages 19 to 59 years. This includes those who are pregnant, because the virus is highly transmissible to a developing baby.

A 2018 study found that administering the hep B vaccine to a pregnant person poses no health risks to that person or to the developing baby.

The hep B vaccine does not contain live or intact hepatitis virus. Instead, it contains a protein that is found on the surface of the virus and was manufactured in a laboratory by yeast. There is no risk of the hep B vaccine causing hepatitis infection in a pregnant person or a fetus.

No. Although a waiting period before conceiving is recommended after certain live-virus vaccines, the hep B vaccine is not one of these.

The hep B vaccine does not contain live or whole hepatitis virus. You and your baby cannot contract hepatitis B as a result of receiving the vaccine.

If you’re planning to conceive soon, ensure that all your recommended vaccines are up to date now. Some vaccine-preventable diseases, including hepatitis B, can be especially dangerous to pregnant people and their babies.

HBV is easily transmitted via contact with the blood or bodily fluids of someone who has the virus, even in the absence of visible blood. Infectious HBV can live on surfaces for up to 7 days. Touching contaminated surfaces and then touching your own mucous membranes or sharing items such as a toothbrush or razor can transmit HBV.

And because chronic HBV might not cause symptoms for years, many people don’t know that they’ve contracted the virus.

For these reasons, many people have an increased risk of contracting HBV, including:

  • sexually active adults
  • healthcare and emergency workers
  • international travelers
  • adoptees from certain regions and their families
  • injection drug users
  • household contacts of people with HBV
  • people who have not been vaccinated against HBV
  • all pregnant people who have not had a hep B vaccine (acquiring HBV during pregnancy poses serious health risks to the newborn)

Mother-to-baby transmission accounts for more than half of global HBV cases. If you contract HBV during pregnancy, your baby is highly likely to contract the virus in the absence of treatment.

Without vaccination or preventive care, up to 90% of babies born to birthing parents with HBV may develop chronic HBV infection. Chronic HBV infection increases a child’s risk of liver cirrhosis and liver cancer. Up to 25% of childhood HBV infections result in premature death.

However, with treatment, doctors can greatly reduce the chances that your baby will contract HBV.

Both pregnancy and HBV can also affect the health of your liver and increase the risk of certain pregnancy complications, so it’s important to make sure your doctor has experience treating HBV in pregnancy.

Testing for HBV infection is a part of routine prenatal screening in the United States, as recommended by the CDC and the World Health Organization (WHO).

If you test positive, treatment is available for you and your baby. Your doctors will do more testing, including an HBV DNA (“viral load”) test. At higher viral loads, your doctor may recommend treatment with an antiviral medication called tenofovir.

All infants born to birthing parents who have HBV generally receive a hep B vaccine and hepatitis B immune globulin (HBIG) within 12 hours of birth. These injections, along with timely completion of the remaining hep B vaccine series, can reduce the risk of your baby contracting HBV by up to 95%.

Knowing your status is the crucial first step. Whether you have chronic HBV or test newly positive during pregnancy, you can manage HBV and protect your baby.

You will need care from doctors who have experience managing HBV in pregnancy. You may need antiviral therapy, and HBV is also associated with a small but increased risk of certain pregnancy complications. Your doctors will monitor you and recommend any necessary treatment.

Depending on your circumstances, doctors can often reduce the chances of your baby contracting HBV to less than 10%.

How long after the hepatitis B vaccine can I get pregnant?

There is no recommended waiting period before conceiving. It’s OK to get the hep B vaccine shortly before or even during a pregnancy.

If you are planning to become pregnant, talk with your doctor now to confirm that all your recommended vaccines are up to date.

How does hepatitis B affect the unborn baby during pregnancy?

HBV generally does not cross the placenta to affect the fetus during pregnancy.

Chronic HBV infection during pregnancy has been associated with a slightly increased risk of complications such as gestational hypertension and preeclampsia, gestational diabetes, placental abruption, fetal distress, fetal growth restriction, and preterm delivery. Your doctor can help monitor for these complications and manage them if they arise.

The primary risk to your baby is HBV infection, and that usually occurs during birth. Your own treatment, coupled with prophylaxis for your newborn, can significantly reduce the risk of your newborn contracting HBV.

The hepatitis B virus (HBV) is a common infection globally. Although universal childhood vaccination has significantly reduced the prevalence of HBV in the United States, the virus still affects millions of people, including many pregnant people.

Infants born to birthing parents with HBV often contract chronic HBV themselves. But proper screening, treatment, and preventive measures can greatly reduce this risk.

The best line of defense for newborns is protected parents. Hep B vaccination is recommended for U.S. adults who are not yet immunized.

Whether you are planning to conceive or are already pregnant, you can safely receive the hep B vaccine to protect yourself and your unborn baby.

And if you’ve tested positive for HBV during pregnancy, treatment is available. Talk with your doctor to learn more about preventive measures to protect your newborn.