Pennsylvania Measles Outbreak Raises Alarm Over Infections in Newborn Babies
Health officials have warned of a rare but potentially life-threatening complication after pregnant women contracted measles and babies were born with the infection.
Pennsylvania is confronting a growing measles outbreak, prompting health authorities to issue new guidance to medical professionals on the risks of infection during pregnancy and the possibility of babies being born with measles.
The Pennsylvania Department of Health reported 1,398 confirmed measles cases as of October 28, 2026, according to its latest reported figures. The outbreak has also been associated with multiple deaths, including infants.
The emerging concern is congenital measles, in which a baby acquires the infection in connection with the mother’s illness during pregnancy or around birth. The condition can be serious, particularly for newborns whose immune systems are still developing.
Pregnant women and newborns face additional risks
State health officials have reported that 66 pregnant women in Pennsylvania contracted measles this year. At least six babies have also reportedly been born with the infection, according to reporting on the state’s health advisory.
Measles during pregnancy can increase the risk of complications for both the pregnant woman and the baby. For the mother, complications may include pneumonia and the need for hospital treatment. Pregnancy-related risks include miscarriage, premature delivery and low birth weight.
Newborns infected with measles may experience outcomes ranging from less severe illness to life-threatening complications.
The situation has prompted the state health department to issue specific clinical guidance for healthcare providers caring for pregnant patients with measles and newborns who may have acquired the infection.
Why vaccination before pregnancy matters
The measles, mumps and rubella (MMR) vaccine is the primary means of preventing measles. However, because it contains live, weakened viruses, it is not recommended during pregnancy.
Health officials therefore advise women to establish their measles immunity before becoming pregnant. Two doses of the MMR vaccine provide approximately 97 per cent protection against measles.
Pregnant women who are not immune and have been exposed to measles may be eligible for immunoglobulin treatment. According to the Pennsylvania Department of Health, this treatment should ideally be administered within six days of exposure to help prevent infection or reduce the risk of serious illness.
Anyone who is pregnant, planning a pregnancy or concerned about possible measles exposure should contact a healthcare professional for advice specific to their circumstances.
Infant deaths add to concerns over the outbreak
The outbreak has also drawn attention to the vulnerability of babies who are too young to receive their first routine measles vaccination, generally administered at around 12 months of age in the United States.
Reports from Lancaster County described two infant deaths in August in which measles was identified as a cause or contributing factor. The circumstances of each death differed, and the reported information does not establish that both infants had congenital measles.
These cases underscore the risks measles can pose to very young children, particularly those who have not yet reached the age for routine vaccination.
Falling vaccination rates fuel renewed concern
Measles was declared eliminated in the United States in 2000, meaning sustained domestic transmission had been interrupted. However, imported infections can spread when they reach communities where vaccination coverage is insufficient.
Health experts have identified declining vaccination rates and gaps in population immunity as important factors contributing to renewed measles transmission.
The Pennsylvania outbreak demonstrates why maintaining high vaccination coverage remains essential, particularly for people who cannot receive certain vaccines because of pregnancy or other medical circumstances.
Public health authorities continue to urge eligible individuals to stay up to date with their vaccinations and encourage pregnant women to discuss immunity and exposure risks with their healthcare providers.
For families planning a pregnancy, checking measles immunity before conception can be an important preventive step. Early medical advice following a possible exposure may also help reduce the risk of severe illness for both mother and baby.
SOURCE: Pennsylvania Department of Health, Health Advisory 842, “Guidance for measles in pregnancy and congenital measles” (2026)
