Pennsylvania health officials alert doctors to rise in measles cases among pregnant women and congenital infections

The Pennsylvania Department of Health issued an alert to physicians on Monday about a growing number of measles infections among pregnant women and a rise in congenital measles, a condition rarely seen in the United States. Since the state outbreak began in April, 66 pregnant women have been diagnosed with measles, according to the department.

"Getting measles while pregnant increases the risk of miscarriage, early labor, and low birth weight," a department spokesperson said in an email.

State law prevents the release of detailed outcomes for those pregnancies, and no national database tracks congenital cases. The outbreak has been concentrated in Amish communities, which may limit reporting. As of Thursday, the United States has recorded 4,410 measles cases this year, with Pennsylvania accounting for 1,286.

Congenital measles occurs when a mother contracts the virus within two weeks before delivery, leading to newborn infection within ten days of birth. Doctors have reported at least six newborns in Pennsylvania with the condition; symptoms range from rash and fever to pneumonia, neurological problems, and low platelet counts. Two infants required intensive-care treatment for pneumonia.

The disease can be fatal and may cause long-term complications, including subacute sclerosing panencephalitis (SSPE), a rare inflammatory brain disorder that can appear years after infection and is typically fatal. There is evidence that SSPE may develop earlier in children born with congenital measles.

No specific cure exists beyond supportive care such as fluids, hydration and supplemental oxygen. Health officials emphasized that vaccination before pregnancy is the most effective prevention, as the measles vaccine, which contains a live attenuated virus, cannot be administered during pregnancy. Unvaccinated pregnant women exposed to measles may receive immunoglobulin within six days of exposure to reduce the risk of severe illness. The vaccine can be safely given after delivery and to breastfeeding mothers.