Women planning pregnancy need measles shot, group says

Women hoping to become pregnant should get vaccinated against measles, or receive a second shot if they have had only one, a prominent medical group announced Wednesday.

Measles endangers both pregnant women and their babies, says physician Neil S. Silverman, a spokesman for the Society for Maternal-Fetal Medicine, whose members specialize in high-risk pregnancies.

Pregnant women who contract measles are at higher risk for severe complications, such as pneumonia. Measles also can cause problems for the pregnancy, increasing the chance of premature labor and delivery, Silverman says.

Because measles vaccine can't safely be given during pregnancy, the society recommends that anyone considering pregnancy be vaccinated in advance, Silverman says. Women can be vaccinated after delivery, even during breastfeeding.

The measles vaccine, introduced in 1963, helped eliminate the routine spread of measles among Americans in 2000. For several years, the only measles cases were "imported" into the USA by travelers, according to the Centers for Disease Control and Prevention.

But measles has come roaring back in recent years, due to large outbreaks abroad as well as growing numbers of unvaccinated children. More than 100 people were diagnosed with measles in January, the CDC says.

People born before 1957 are considered to be immune to measles, since infection was nearly universal among children then.

For three decades, children typically got only one measles shot. After a large measles outbreak in 1989 to 1991 -- in which 55,000 people were sickened and 166 died -- researchers discovered that a significant number of children weren't getting that first shot, says William Schaffner, a professor at the Vanderbilt University School of Medicine.

The CDC has recommended that children get a second shot since 1993. While one dose of measles vaccine protects 93% of people, two doses protects 97%, says the CDC's Gregory Wallace.

People can get a blood test to see whether they are adequately immunized against measles, Wallace says. If the test shows they have inadequate antibody levels, they can get a second measles shot. The blood test is actually more expensive than a vaccine, however.

"If there's a question or lack of documentation about a patient having received a second MMR (measles-mumps-rubella) vaccine, it's best to vaccinate," the medical society said in a statement. "There's no danger or risk if a person receives a third shot and it turns out that they did receive two shots in the past."

The CDC doesn't recommend that most people get a second measles shot. But the agency does suggest a second measles shot for certain people at high risk of contracting and spreading the virus: those planning foreign travel; those who work in health-care settings, from doctors to janitors; and college students, Wallace says.

While babies typically get their first measles shots at 12 to 15 months of age, babies can be vaccinated against measles as early as 6 months, the CDC says.

California health officials have warned unvaccinated people -- and parents of babies too young to have been vaccinated -- to stay away from Disneyland and other crowded venues. The maternal-fetal medicine society also recommends pregnant women avoid large crowds if they're not sure whether they're immune.