Topic Overview

Your immunity protects both you and your fetus. After you have been immunized (vaccinated) against or infected by a virus or bacteria, your body develops an immunity to that infectious agent. Full immunity can protect you from future infection, either for a lifetime or a limited period. Partial immunity strengthens your body’s ability to fight that infection.

Before you become pregnant, be sure to review your immunization history with your doctor. Depending on the virus or bacteria, having had an immunization in childhood may not guarantee that you now have full immunity. To help ensure a healthy pregnancy, make sure that you are immune to the following before conceiving:

• Chickenpox
• Hepatitis
• Measles
• Mumps
• Polio
• Rubella
• Whooping cough (pertussis)

Before pregnancy: Rubella, measles, mumps, chickenpox

Rubella, measles, mumps, and chickenpox can harm a growing fetus. They can cause birth defects, fetal death, or premature birth. Chickenpox can also be dangerous for you when you’re pregnant.

If you don’t know whether you’re immune to rubella, measles, or chickenpox, talk to your doctor about a blood test for antibodies to that virus. If you aren’t immune, have the vaccination before becoming pregnant. To allow time for your body to develop antibodies to the virus, keep using birth control for at least 4 weeks after the vaccination.^{footnote 1}

Your children should receive their immunizations on schedule. Having your child vaccinated against diseases does not increase your risk for becoming infected with them. You do not need to speed up or delay your child’s immunizations.

Before or during pregnancy: Flu and whooping cough (pertussis)

Flu and whooping cough are dangerous diseases for newborns and young infants. The flu can also be dangerous for you when you’re pregnant. Getting the flu and Tdap vaccines during pregnancy is considered safe for your fetus. And these vaccines protect both you and your newborn. The U.S. Centers for Disease Control and Prevention (CDC) recommends:

• If you didn’t get the yearly flu vaccine yet, get the flu shot before or during your pregnancy.^{footnote 2} This is especially important if you have a chronic health problem (including asthma). The intranasal vaccine contains live virus, so it is not used during pregnancy.
• Get a tetanus, diphtheria, and pertussis (Tdap) shot before or during each pregnancy.^{footnote 1}
• People who expect to have close contact with your baby should also get the flu and Tdap shots if they haven’t had them. It’s best to get them at least 2 weeks before contact with your baby.

If you are already pregnant and are not immune

If you are not immune to rubella, measles, or chickenpox, your doctor will recommend that you not have the vaccine until after childbirth. Instead, you must take every precaution to prevent exposure to these viruses while you’re pregnant.

If you are at risk of being exposed to hepatitis B, hepatitis A, rabies, polio, meningitis, or pneumococcal bacteria, your doctor may recommend that you get vaccinated against these infections during pregnancy.

If you are age 26 or younger and you did not already get the human papillomavirus (HPV) vaccine before you became pregnant, your doctor may suggest this vaccine after pregnancy.

Smallpox has been eliminated from all places in the world except for research labs. Smallpox vaccine is not recommended during pregnancy because of the small chance that it can affect you or the fetus. But risks related to the vaccine are not as great as the risk of having smallpox infection. So, in the unlikely event that you have or may have been exposed to smallpox, you would be vaccinated to reduce the severity of this life-threatening illness.

Routine vaccination is safe for you and your baby during breastfeeding.

For more information, see the topic Immunizations or see the topics related to the specific illnesses mentioned above.