Before Pregnancy

Measles, mumps, and rubella are all serious viral infections that can cause pregnancy complications such as miscarriage, stillbirth, premature birth (birth before 37 weeks of pregnancy) and low birth weight in newborn babies.²⁻³ While all three of these infections are harmful, rubella (also known as ‘German Measles’) is particularly dangerous during pregnancy. The rubella virus can be passed from an infected birth parent to their developing baby during pregnancy, causing health problems in the eyes, ears, and heart, known as congenital rubella syndrome.¹⁻³

The best way to protect you and your developing baby from measles, mumps, and rubella is by getting vaccinated. Protection against all three of these diseases is provided in one vaccine known as the MMR (measles, mumps, rubella) vaccine. Many adults received the MMR vaccine as children. However, as protection can decrease over time, your healthcare provider may still recommend a blood test to make sure your body has immunity (protection) against these infections before getting pregnant.

The MMR vaccine is especially important to consider before pregnancy because it is a live-attenuated vaccine. You should receive the MMR vaccine at least 4 weeks before becoming pregnant.

Live-attenuated vaccines like MMR are not routinely recommended in pregnancy because of a small theoretical risk to developing babies. This risk is ‘theoretical’ because real-life data shows that babies born to a parent who got a live or live-attenuated vaccine during pregnancy (often without knowing they were pregnant) don’t have higher rates of birth defects or infections related to the vaccine. Getting a live or live-attenuated vaccine during pregnancy is not a reason to consider terminating (ending) a pregnancy.

Varicella or ‘Chickenpox’ is a very contagious infection caused by the varicella-zoster virus (VZV) and can lead to serious illness and pregnancy complications.4 The virus can be passed from an infected birth parent to their developing baby during pregnancy, causing a condition known as congenital varicella syndrome. This condition involves health problems that affect the head, muscles, bones, eyes, and cognitive (brain) function.⁵

Many adults already have immunity (protection) against the varicella virus because they either had chickenpox as a child or received the vaccine. However, protection can decrease over time. Your healthcare provider may still recommend a blood test to make sure you are immune to the virus before getting pregnant. If not, the chickenpox vaccine is highly recommended before pregnancy because it is a live-attenuated vaccine and not recommended during pregnancy. Like the MMR vaccine, the chickenpox vaccine should be given at least 4 weeks before becoming pregnant.

Hepatitis B is a serious infectious disease caused by the hepatitis B virus (HBV). It mainly affects the liver. It passes from person to person through blood and body fluids. Hepatitis B can pass from mother to baby during birth, which is the most common way for babies to get hepatitis B early in life.

It’s very important to prevent newborn babies from getting hepatitis B. The younger a person is when they catch HBV, the greater their chances of developing a chronic (long-term) infection.⁶ 9 out of 10 babies who catch hepatitis B at birth will develop a lifelong, chronic infection.⁶

The hepatitis B vaccine is recommended for anyone who hasn’t received the vaccine in the past. Your healthcare provider should perform a blood test to check if you are already immune (protected against) hepatitis B. If you are not immune, getting the hepatitis B vaccine is recommended. This vaccine is also safe to get during pregnancy.¹

There may be specific situations that require you to get additional vaccines. For example, your healthcare provider may recommend other vaccines if you are traveling to parts of the world where diseases like typhoid fever or hepatitis A are more common. It's a good idea to talk to your healthcare provider to find out if there are any additional vaccinations that would be beneficial for you.