Pennsylvania Measles Outbreak Sparks Concerns Over Congenital Infections

Pennsylvania is experiencing a surge in measles cases, with hundreds infected and several fatalities attributed to the highly contagious disease. This outbreak has brought a disturbing development: the emergence of congenital measles, a rare condition where the virus is transmitted from an infected mother to her baby before or during birth.

For decades, widespread vaccination and natural immunity from childhood infections meant that women of childbearing age typically possessed immunity to measles. However, declining vaccination rates have led to a resurgence of the disease, and consequently, a rise in cases among individuals who lack prior immunity, including pregnant women and their newborns.

"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."

Congenital measles can lead to severe complications for newborns, including pneumonia, encephalitis, and even death. It also increases the risk of subacute sclerosing panencephalitis (SSPE), a fatal and incurable neurological disorder. Historically, such cases were rare because most women had natural immunity. The measles vaccine, while highly effective, contains a live, weakened virus and cannot be administered during pregnancy.

Last month, a case in Lancaster County highlighted the severity of measles during pregnancy. A woman with measles delivered a stillborn baby, whose death was attributed to a ruptured spleen, a complication classified as measles-associated. The midwife reportedly linked the infant's death to the mother's severe measles infection and lack of vaccination.

According to the latest federal data as of September 18, the U.S. has recorded 3,471 confirmed measles cases in 2026 across 39 outbreaks. This total has already surpassed the 2,289 cases reported in 2025, which marked the highest annual tally in over 30 years. Health officials recommend that pregnant women who are not immune be vaccinated before pregnancy or after delivery. If exposed to measles, non-immune pregnant women should seek immediate medical attention, as immunoglobulin therapy can be administered within six days of exposure to mitigate the risk or severity of infection.