Pennsylvania’s measles outbreak has taken a disturbing turn.
The highly contagious disease has ripped through communities across the Keystone State in recent months, sickening hundreds, sending scores to the hospital and claiming four lives.
Now, as the virus continues to spread, doctors are seeing it turn up in patients they rarely encountered before — and learning how to treat them in real time.
Enter: Congenital measles, a potentially life-threatening condition that occurs when a mother who is infected around the time of delivery passes the virus onto her baby in the womb or during birth.
For much of history, cases like these were rare. Before vaccines, most people were infected with measles during childhood, so women typically had lasting natural immunity by the time they had children of their own.
Later, widespread vaccination provided that same protection without requiring people to contract the disease.
But measles, once declared eliminated in the US, is making a comeback nationwide as vaccination rates decline and fewer young adults have natural immunity from prior infection.
“Because of this, we’re literally seeing new forms of measles,” Dr John Goldman, an infectious disease specialist at the University of Pittsburgh Medical Center, told The Guardian. “We don’t have a lot of information about what happens with it.”
Just last month, a woman with measles in Lancaster County, Pennsylvania, delivered a stillborn baby who died from a ruptured spleen in a case the coroner classified as a measles-associated death.
The midwife who attended the birth told the mother that the baby’s death was linked to her severe case of measles and lack of vaccination, according to The Atlantic.
Measles during pregnancy can increase the risk of pregnancy loss, premature delivery and low birth weight. Up to 30% of babies whose mothers are infected around the time of delivery may also contract the virus, putting them at risk for serious illness.
“Congenital measles typically presents in the newborn with fever and rash within the first 10 days of life, and can occasionally cause severe complications such as pneumonia, encephalitis and even death,” Dr. Manish Trivedi, head of infectious diseases at AtlantiCare, told The Post.
The trouble may not end there. Congenital measles also increases the risk of subacute sclerosing panencephalitis, or SSPE, a rare and progressive neurological disorder that causes widespread inflammation and scarring in the brain. It is almost always fatal and has no cure.
Adding to the concern is that few pediatricians across the country have experience treating newborns infected with the virus.
Earlier this month, the American Academy of Pediatrics published an FAQ on congenital measles to help address that knowledge gap, laying out guidance on preventing, diagnosing and treating the infection in newborns whose mothers have measles.
And this isn’t just a theoretical concern.
“If measles keeps spreading, we’re going to see more pregnant women exposed to the virus,” Trivedi said.
As of Sept. 18, 3,471 confirmed measles cases had been reported across the US in 2026, according to the latest federal data, spanning 39 outbreaks.
With more than three months still left in the year, that has already surpassed 2025’s total of 2,289 confirmed cases — the highest annual tally in more than three decades.
But Trivedi stressed that not all pregnant women are in immediate danger.
“Pregnant women are considered at higher risk for complications from measles, but those who already have evidence of immunity are generally well protected,” he said. “The greatest concern is for pregnant women who are not immune and become exposed or infected.”
Trivedi recommends that pregnant women check their vaccination history or immunity with their health care provider, especially if they’ve been exposed to measles or live in or travel to an area with an outbreak.
The catch: The MMR vaccine contains a live, weakened version of the measles virus and can’t be given during pregnancy.
“Women who are not immune should be vaccinated before pregnancy or after delivery,” Trivedi said.
“If a nonimmune pregnant woman is exposed to measles, she should contact her healthcare provider immediately because intravenous immune globulin can be given within six days of exposure to reduce the risk or severity of infection,” he advised.
