Women who are pregnant or who plan to become pregnant should avoid contact with all rodents, including pet hamsters, mice and guinea pigs. The U.S. Centers for Disease Control and Prevention issued this recommendation in August 2005. These animals can spread diseases that can harm your baby.

One of the diseases is caused by a virus called LCMV (lymphocytic choriomeningitis virus). During pregnancy, LCMV infection can cause severe illness in the fetus. Serious problems can include excess fluid in the head (hydrocephalus), developmental problems, blindness and even death.

Scientists do not know how often LCMV infection causes such defects to occur. Most infections appear to be caused by wild house mice, not pets.

LCMV infection in persons with normal immune systems is usually a mild illness. Symptoms include fever, headache, neck stiffness, fatigue, lack of appetite, muscle aches, nausea and vomiting. But if a person has an impaired immune system, the infection can be more serious.

What You Can Do

• Avoid contact with wild rodents. If your house has rats or mice, take care of the problem promptly. Ask another family member to handle it, or bring in a professional pest control company. Traps are probably the best choice. Some pest control products contain chemicals that can be dangerous to you and your fetus. Talk to your health care provider before using any pest control chemicals in your house. 
• If you have a pet rodent, keep it in a part of the house where you spend little time. Ask another family member or friend to clean the cage and care for the pet. The risk of infection from pet rodents is low, but it's best to be cautious.
• If you have children, be sure an adult closely watches them when they are around pet rodents. This is especially important for children under the age of 5. No one should kiss pet rodents or hold them close to the face. Anyone who plays with the animals or cleans their cages or bedding should wash their hands afterwards.

For More Information
The U.S. Centers for Disease Control and Prevention has more information, including how to safely handle pet rodents and clean cages.

August 2005