More than 20,000 babies in the United States were born with birth defects during an outbreak of rubella in 1964 to 1965 (1). The same outbreak also resulted in at least 10,000 miscarriages and stillbirths (1).

Fortunately, rubella has been largely eliminated in the United States (2). A vaccine for rubella became available in 1969. Since then, children have been routinely vaccinated, helping to prevent the spread of the illness to susceptible pregnant women. Most women of childbearing age are immune to rubella because they either were vaccinated or had the illness during childhood. Because of widespread use of the vaccine, birth defects caused by rubella have become rare in the United States (only four cases were reported between 2001 and 2004, which resulted from imported infections) (2).

Rubella remains widespread in many countries, however, and travelers continue to bring cases into this country. For this reason, the potential for susceptible pregnant women to become infected does exist. About 10 percent of women of childbearing age in the United States are susceptible to rubella (3). Women can protect their future children from the effects of rubella by getting tested for immunity before pregnancy and getting vaccinated if they are not immune.

What is rubella?
Rubella is a mild, contagious illness caused by a virus. It is characterized by a rash, swollen glands and, especially in adults, joint pain. The rash usually lasts about three days and may be accompanied by a low-grade fever. Up to half of infected individuals have no symptoms at all (1).

What risks does rubella pose for the fetus?
Babies whose mothers contract rubella during pregnancy are often born with one or more birth defects that, together, are called congenital rubella syndrome (CRS). Maternal infection (1, 3):

• In the first 12 weeks of pregnancy results in birth defects in up to 85 percent of cases
• From 13 to 16 weeks of gestation results in birth defects in 54 percent of cases
• At the end of the second trimester results in birth defects in 25 percent of cases

These include eye defects (often resulting in blindness), hearing impairment, abnormalities of the heart, mental retardation, and a few rare disorders. The infection also causes miscarriage and stillbirth.

Some infected babies appear normal at birth and during infancy. However, all babies whose mothers had rubella during pregnancy should be monitored carefully because problems with vision, hearing, learning and behavior may first become noticeable during childhood (1). Children with CRS also are at increased risk for diabetes (1).

How are babies with CRS treated?
There is no specific treatment for CRS. Certain problems that are common in the newborn period (such as blood and liver abnormalities) usually go away without treatment. Other individual birth defects (such as eye or heart defects) sometimes can be corrected or at least improved with early surgery. Babies with hearing or vision loss may benefit from special education programs that provide early stimulation and build communication and learning skills. Children with mental retardation also may benefit from early special education. 

How can a woman find out if she is immune to rubella?
A simple blood test can determine whether a person is immune to rubella. The blood test shows whether a person has virus-fighting substances called antibodies in the blood. Rubella antibodies are produced by people who have had the infection or were vaccinated against it.

Can CRS be prevented?
The March of Dimes recommends that:

• All women be tested for immunity to rubella before they become pregnant

• They consider being vaccinated if they are not immune

A nonimmune woman can be vaccinated with the rubella vaccine alone or with the combined measles-mumps-rubella (MMR) vaccine, to protect her future children from CRS.

Women who were not tested before pregnancy are routinely tested during an early prenatal visit. If a pregnant woman is not immune, she should avoid anyone who has rubella. If a susceptible pregnant woman is exposed to rubella, she should contact her health care provider. The provider may treat her with a shot of immune globulin to attempt to reduce her risk of infection, though it is not known how effective this approach may be in preventing rubella in mother or baby (3).

Pregnant women who are not immune should be vaccinated after delivery, so that they will be immune during any future pregnancies (1, 3). A woman who is breastfeeding her baby can safely be vaccinated (3).

The rubella and MMR vaccines are not recommended during pregnancy. A woman should wait 28 days after vaccination before she attempts to conceive (4).

Can being vaccinated against rubella around the time of conception harm the fetus?
Babies of women who are inadvertently vaccinated around the time of conception are unlikely to be harmed by the vaccine. The U.S. Centers for Disease Control and Prevention (CDC) studied 226 women who were vaccinated with the currently used form of the vaccine from three months before to three months after they conceived (4). None of the women's babies had birth defects that resembled the defects that rubella causes. However, the CDC continues to recommend postponing conception for 28 days after vaccination because there is theoretically a very small risk of fetal harm.

Who else should be vaccinated?
All children should be vaccinated against rubella unless there is a medical reason why they should not be. Widespread vaccination of children helps prevent the spread of this illness to others, especially pregnant women.

The first vaccine dose is routinely given at 12 to 15 months of age in combination with the measles and mumps vaccines. A child should not receive the first dose of MMR before 12 months of age. Before 12 months, a baby still has some of his mother's antibodies, which can interfere with the vaccine and keep it from working. A second dose of MMR is given at age 4 to 6 years.

Vaccination of teenagers or adults in colleges, workplaces, hospitals (staff and volunteers) or military bases helps prevent outbreaks in those areas. The CDC recommends that all health care workers who are not immune be vaccinated to protect patients from infection (1). Susceptible women of childbearing age also should consider being vaccinated before traveling abroad, as rubella is widespread in many countries.

For more information
Read the fact sheet provided by the Organization for Teratology Information Services (OTIS).

References

1. Centers for Disease Control and Prevention (CDC). Rubella. Accessed 4/30/07.

2. Centers for Disease Control and Prevention (CDC). Achievements in Public Health: Elimination of Rubella and Congenital Rubella Syndrome—United States, 1969-2004. Morbidity and Mortality Weekly Report, volume 54, number 11, March 25, 2005, pages 279-282.

3. American Academy of Pediatrics (AAP). Rubella. In: Pickering, L.K., et al. (eds.), Red Book: 2006 Report of the Committee on Infectious Diseases, 27th Edition. Elk Grove Village, IL, American Academy of Pediatrics, 2006, pages 574-579.

4. Centers for Disease Control and Prevention (CDC). Guidelines for Vaccinating Pregnant Women. Accessed 4/30/07.

July 2007