Can I Get the MMR Vaccine While Pregnant?

When we become pregnant, we often look at our own health through a different lens. Our bodies are housing new life, and we want to do everything in our power to keep that life safe. As such, if we skipped certain health protocols in the past, we may decide that we want to adopt them now.

For example, if you refrained from taking the MMR vaccine, or if your parents decided to forgo it while you were a child, you might want to get it now that you are pregnant. Alternatively, you may have gotten blood work done and found out that your immunity to one or more of the viruses covered under the MMR vaccine has waned.

Unfortunately, getting the MMR vaccine during pregnancy is not an option, says Jennifer Jolley, MD, an OB-GYN with UCI Health and associate clinical professor. “Although other types of vaccines are considered safe during pregnancy, MMR is a live attenuated virus vaccine and could theoretically cause harm to the pregnant person and baby if viral infection occurs,” she explains.

What Is the MMR Vaccine?

The MMR vaccine is an inoculation that protects against three viruses: measles, mumps, and rubella. All three of these viruses cause disease that can lead to serious medical issues, and in some cases, death. The MMR vaccine is a safe and effective way to prevent someone from contracting measles, mumps, and rubella.

Measles is a serious illness that can cause a fever, rash, congestion, and cough; if untreated, it can result in brain damage, pneumonia, and even death. Mumps causes fever, fatigue, muscle pain, and swelling of the salivary glands. Serious complications of mumps include swelling of the testicles or ovaries, hearing loss, encephalitis, meningitis, and death.

Symptoms of rubella include fever, rash, and headache. Pregnant individuals who get rubella are prone to miscarriage, and their babies may be born with birth defects.

The MMR vaccine is usually given in childhood, according to the vaccine schedule recommended by the CDC. It’s recommended that children get a dose of the MMR vaccine sometime between 12 and 15 months, followed by a second inoculation sometime between 4 and 6 years old. If you did not get an MMR vaccine during childhood, it is recommended you get one or two doses of the MMR vaccine, depending on your risk factors.

Is It Safe to Get the MMR Vaccine During Pregnancy?

While the CDC recommends that adults get an MMR vaccine if they didn’t get vaccinated in childhood, pregnancy is one of the contraindications for this vaccine. The CDC recommends that anyone planning on becoming pregnant check with their doctor to make sure they’ve been vaccinated or have immunity against measles, mumps, and rubella. If you don’t have immunity, you can get one dose of the MMR vaccine, but it should be done at least one month prior to the start of pregnancy.

Cindy M. Duke, MD, OB-GYN, a fertility doctor and virologist, explains that the reason the MMR is contraindicated in all people who are pregnant is because of the type of vaccine that the MMR vaccine is. “This is a live attenuated virus vaccine, which means actual weakened versions of these viruses are in the vaccine," she explains.

As such, the viruses contained in the vaccine are able to cross the placenta, and potentially infect your fetus, says Dr. Duke. If that were to happen, it could lead to birth defects, decreased fetal growth, or miscarriage/pregnancy loss.

As Molly McAdow, MD, OB-GYN, an instructor of obstetrics at Yale-New Haven Hospital describes, although the MMR vaccine contains live virus, it’s a weakened version of the virus and does not make people with fully developed immune systems ill. However, unborn babies do not have the same immune system as a toddler or child who gets a dose of the MMR vaccine.

“Because fetal immune systems are developing, they are theoretically at risk to become sick from viruses or bacteria that would not harm people with mature immune systems,” Dr. McAdow explains. She says that risk to the developing fetus is the primary reason why the MMR vaccine is never recommended during pregnancy.

What If I Get the MMR Vaccine Before Realizing I’m Pregnant?

If you received the MMR vaccine before realizing you had conceived, don’t panic. Although getting the MMR vaccine during pregnancy is not recommended, the risks to you and your baby are low and are not a reason to terminate your pregnancy.

It’s best to wait at least four weeks after receiving an MMR vaccine before attempting to get pregnant, says Dr. McAdow. But sometimes pregnancy can take you by surprise. “If a patient is vaccinated before learning she is pregnant, I would reassure her that the risk of congenital rubella syndrome or of miscarriage are incredibly low,” she says.

If this happens to you, Dr. Duke recommends a period of “watchful waiting.” Make sure you share this information with your healthcare provider so they can keep a cautious eye on your pregnancy and your developing baby.

Risks of Getting the MMR Vaccine While Pregnant

Receiving the MMR vaccine during pregnancy puts your pregnancy and your baby at risk for serious outcomes. Again, this is because the MMR vaccine contains live, weakened viruses that can potentially cross the placenta and cause harm.

Let’s take a look at some of the potential complications the MMR vaccine can cause if taken during pregnancy. 

Congenital Rubella Syndrome

According to Dr. Jolley, if your fetus becomes infected with rubella, they can develop a complication called congenital rubella syndrome.

This syndrome can cause intellectual disabilities, heart defects, and hearing loss, Dr. Jolley explains. As the CDC notes, the risks of congenital rubella syndrome are highest in the first 12 weeks of pregnancy and diminish significantly after 20 weeks.

Birth Defects and Restricted Fetal Growth

Fetal infection with measles can also cause birth defects, says Dr. Duke. Additionally, the measles infection can lead to restricted fetal growth, known as intrauterine growth restriction or IUGR, Dr. Duke explains.

Child Loss and Premature Delivery

Individuals who receive the MMR vaccine while pregnant have an increased risk of experiencing a miscarriage or pregnancy loss, Dr. Duke explains. Premature birth is also a concern for pregnant people who receive this vaccine, she says.

When Can I Get the MMR Vaccine?

If you never had the MMR vaccine or do not have immunity to the viruses it protects from, you can get an MMR vaccine after your baby is born. “The MMR vaccine is routinely given to postpartum individuals who did not have documented immunity during the pregnancy,” Dr. Jolley offers.

Thankfully, there is no reason why you can’t take the vaccine if you are breastfeeding. According to Dr. Jolley, not only is taking the vaccine safe for your breastfed baby, but if you are breastfeeding, antibodies from the vaccine can pass into your milk, thereby protecting your baby.

Pregnancy Safe Alternatives

Unfortunately, there is no alternative vaccine you can take during pregnancy to protect you from measles, mumps, and rubella. If you did not get your vaccine prior to becoming pregnant, you will need to wait until after your baby is born to get the MMR vaccine.

That said, if you are concerned about contracting one of the viruses that the MMR vaccine protects against, there are several things you can do to keep yourself and your baby safe. 

Practice Infection Control

If you are near others who may be infected with measles, mumps, or rubella, or if you are living in an area that is having an outbreak, good hygiene practices are important. These include frequent hand washing and limiting contact with anyone who may be infected, Dr. Jolley suggests. Ensuring that you surround yourself with others who have been immunized against these viruses is key as well, she says.

Limit Contacts

If you know anyone who has been infected with measles, mumps, or rubella, you should avoid contact with them if you are not immune to these viruses, says Dr. Duke. You should also avoid others who are unvaccinated with the MMR vaccine, or who have recently recovered from an infection, she says.

Limit Travel

You should limit travel to places where there have been recent outbreaks of these diseases, says Dr. Jolley. Some locations in the U.S. have had measles outbreaks over the past several years, so you should not travel to those locations. Although rubella is very rare in the U.S., there are outbreaks in other countries at times, and you shouldn’t travel to those places, Dr. Jolley recommends.

Post-Exposure Treatments

If you are pregnant, not immune to measles, and are exposed to the virus, you may be able to receive treatment with measles antibodies (known as “post-exposure prophylaxis") to fight your infection, says Dr. Jolley. “This is a different way of providing protection against measles infection in people who are not immune and shouldn’t receive the MMR vaccine during pregnancy,” she clarifies.

You should speak to a healthcare provider about what treatments are available to you should you be exposed or infected with measles, or any of the viruses that the MMR vaccine protects against.

A Word From Verywell

Pregnancy is a time for increased worry for many of us. We want to do everything in our power to keep our babies healthy and safe. If you have learned that you are not immune to measles, mumps, or rubella, or if you never got an MMR vaccine as a child, and were hoping to get it now, you might feel upset when you find out that getting this vaccine is not an option during pregnancy.

The good news is that these viruses don’t circulate very widely in the U.S., and there are several things you can do to ensure that you don’t become infected with one of them. If you have further questions about how to protect yourself from measles, mumps, or rubella, make sure to bring these concerns to a healthcare provider.