Measles cases grow among pregnant women in Pennsylvania: What to know about risks
Measles cases in Pennsylvania have now surpassed 1,500, according to data reported on Monday. As the outbreak continues to grow, doctors and health officials are concerned about a rising number of cases among pregnant women, posing a risk to both mom and baby.
As of Nov. 6, "the Pennsylvania Department of Health (DOH) has now confirmed that 97 of the state's measles cases in 2026 were in pregnant women," Stephanie Nojiri, the DOH deputy press secretary, told ABC News.
There were only 16 total measles cases in the state in 2025 and 6 total in 2024, according to the Centers for Disease Control and Prevention (CDC).
"Because measles was declared eliminated in the United States decades ago, modern data related to measles during pregnancy and the related risks is limited, but clinical studies and systematic reviews provide clear statistical evidence of the dangers associated with contracting measles while pregnant," the PA DOH said in a statement.
"The 97 cases of measles confirmed in pregnant women thus far in 2026 is the highest number of cases in that demographic in Pennsylvania in decades," the state department of health said. "Pennsylvania has not seen an overall outbreak of this size in 35 years."
The department added it "has provided clinical consultation for pregnant women with measles throughout the outbreak."
The PA DOH released guidance about measles in pregnancy in a health alert last month. In addition to posing a risk to the mother's health, measles infection in pregnancy can be transmitted to the baby before birth, leading to congenital measles.
Risks of measles to mom and baby
The CDC warns that measles infection during pregnancy can lead to complications including pneumonia and death, as well as pregnancy loss, premature delivery, and low birth weight for their babies.
"You have to watch the mother fetus dyad so closely because of the risk of fetal death," Dr. Sharee Livingston, an OBGYN at UPMC Magee-Womens in Central Pennsylvania, told ABC News. "You're paying attention to things like growth restriction and ensuring that there's fetal well-being, so that you can intervene with delivery if the fetus is viable."
Livingston said she has taken care of several pregnant women with measles in this outbreak.
"That's a scary place to be for the patient, for the supporter, for the healthcare provider to know that you have a person with a communicable disease that is preventable, and that could put both her and her fetus at risk," Livingston said. "It's a very challenging position to be in."
If transmitted in utero, a baby can be born with congenital measles, "characterized by a febrile rash syndrome within 10 days of birth," the CDC says. These babies are at risk of many health complications including pneumonia, encephalitis, and death.
Dr. Paul Offit, director of the Vaccine Education Center at the Children's Hospital of Philadelphia, said the risk of congenial measles is highest when the baby is delivered within 10 days of the mother developing a rash from measles.
If the baby survives in the short term, a congenital measles infection places them at higher risk of later developing a progressive and fatal neurological condition called subacute sclerosing panencephalitis (SSPE), the CDC says.
SSPE is characterized by "a deterioration in social skills, deterioration in personality, deterioration in handwriting. You descend into a vegetative state and die," Offit said. "The difference for congenital measles is you don't have to wait five or seven years. It can happen in a few months. It can happen within two years."
Overall, cases of congenital measles have been very rare in the United States.
Offit explained that congenital measles has historically been very rare because most adults were immune to the virus from infection in childhood before widespread immunization.
"We're learning about congenital measles. We really are," Offit said. "In the measles era, meaning before the [1963] vaccine ... Children would get infected, so they wouldn't get infected as adults."
Now, Offit said we are seeing the impacts of a growing adult population who are not immune to the virus.
"You have people in their 20s, 30s, and 40s now who really didn't grow up in the age of measles," Offit said. "They are extremely unlikely they would have been naturally infected, and they've chosen not to vaccinate. So now, what you have that I didn't have when I was a child was a fairly large population of vulnerable adults."
Tracking cases of congenital measles is also complicated by lack of standardized reporting in the U.S.
The PA DOH said in a statement there is "no national public health case definition for standardized reporting or tracking of congenital measles cases." The department added, "DOH is working closely with our colleagues at the Centers for Disease Control and Prevention (CDC) to develop standard definitions and tracking tools for congenital measles cases."
Treatment and prevention
The CDC says pregnant women should not receive the MMR vaccine because it contains some live virus, but they can receive immunoglobulin antibodies. This can reduce the risk of infection if they are non-immune and exposed to measles in pregnancy or to help lessen the severity of illness if infected.
There is no specific treatment for congenital measles, but newborns can also receive immunoglobulin if they are born to a mother with measles which may help lessen the severity or risk of death from congenital measles, the CDC says.
Dr. Holly W. Cummings, an OBGYN and chair of the Pennsylvania section of the American College of Obstetricians and Gynecologists, said that preconception counseling about vaccines is very important to help prevent more pregnant women from getting measles.
"Optimum pregnancy care for everybody, even outside of the context of a measles outbreak, is to have preconception care," Cummings said. "See your healthcare provider before you get pregnant, so that you can talk about any health planning that needs to be taken into account before pregnancy. One of those things we routinely think about before pregnancy is vaccination status."
It is also recommended for the people around pregnant women and young babies to be up to date on vaccines too, adding an extra layer of protection for them.
"If you're a family member with a pregnant woman in your family, she would no longer be able to be vaccinated, but other people in the family could be," Cummings said. "So that's the next best thing for creating a safe environment for the pregnant woman and the unborn fetus and the eventual baby that's going to join the family."
Jade A. Cobern, MD, MPH, is a practicing physician, board-certified in pediatrics and general preventive medicine, and is a fellow of the ABC News Medical Unit. Dr. Elizabeth Herrin also contributed to this story.
