MMR Vaccine During Pregnancy

Should You Worry If You Accidentally Got the Shot After Conceiving?

pregnant woman getting shot
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Acquiring rubella (German measles) during pregnancy can cause miscarriage and other major problems, so women are encouraged to keep up-to-date on MMR vaccinations as a way to decrease the risks. But if you accidentally had an MMR vaccine during pregnancy, should you worry? 

Rubella in Pregnancy

First, let's review why it's especially important for women of childbearing age to get the MMR (Measles, Mumps, and Rubella) vaccine.

Infection with the rubella virus, which can cause mild flu-like symptoms and rash in children and adults, generally isn't serious. It's also extremely rare in the U.S. thanks to childhood vaccinations. However, if an expectant mother contracts it and passes it to her developing baby in the womb, it can cause very serious harm to the baby: 

The MMR Vaccine in Pregnancy

The MMR vaccine is prepared with weakened live viruses, so doctors usually advise avoiding pregnancy for at least a month after receiving the vaccine to reduce the risk of becoming infected.

But occasionally, women might not be aware that they are pregnant when they are vaccinated. Others might accidentally get pregnant sooner than one month after receiving the MMR vaccine.

If you are in this situation, try not to panic. 

The advice to wait to get pregnant after a rubella vaccination is based on a theoretical risk of problems to the fetus rather than documented evidence of risk.


In the studies looking at accidental MMR vaccination during pregnancy:

  • None of the subjects gave birth to a baby with congenital rubella syndrome. 
  • Miscarriage rates were not higher than in the general population. 

Researchers concluded that the rubella vaccination does not seem to be risky in early pregnancy.

Still, erring on the side of caution, doctors continue to advise waiting a bit to get pregnant. And they recommend against vaccinating women known to be pregnant.

If you found out that you were pregnant soon after receiving an MMR vaccination, there's no cause for alarm and chances are that everything will be fine. Still, be sure to mention the matter to your doctor in case he or she wants to monitor you - just to safe.

When Should You Be Vaccinated?

According to the Centers for Disease Control and Prevention (CDC), all adults born in 1957 or later should have at least one MMR shot unless:

  • lab tests show they are immune to all to all three diseases (measles, mumps and rubella)
  • the immunization is medically contraindicated for them

If you are planning on becoming pregnant soon and haven't been vaccinated (or don't know if you were), you can be tested for immunity. You're probably immune if you had the shot or were infected with rubella in the past.

If you're not immune, get the MMR shot and wait a month to start trying to conceive.

If you are immune, you don't have to wait!

If you're already pregnant and aren't immune, get the shot after you give birth. This will keep you from getting sick and passing the infection to your baby, and will protect your future pregnancies.


Adult Immunization Schedule. Centers for Disease Control and Prevention. February 1, 2016.

Rubella and pregnancy. March of Dimes. March 2012.

Rubella and your baby. March of Dimes. April 2012.

Badilla, X., Morice, A., Avila-Aguero, M., et al. (2007). Fetal Risk Associated With Rubella Vaccination During Pregnancy. Pediatric Infectious Disease Journal.

Bar-Oz, B., Levichek, Z., Moretti, M.E., et al. (2004). Pregnancy outcome following rubella vaccination: A prospective controlled study. American Journal of Medical Genetics.

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