Cytomegalovirus and pregnancy

Cytomegalovirus (also called CMV) is a kind of herpesvirus. There are many kinds of herpeviruses. Some are sexually transmitted diseases, some can cause problems like cold sores and some can cause infections like CMV. Many people get CMV at some point in their lives, most often during childhood.

If you have CMV during pregnancy, you have a 1-in-3 chance (33 percent) of passing it to your baby. CMV is the most common virus passed from mothers to babies during pregnancy. About 1 to 4 in 100 women (1 to 4 percent) have CMV during pregnancy. Most babies born with CMV don’t have health problems caused by the virus. But CMV can cause problems for some babies.

You can pass CMV to your baby at any time during pregnancy. It’s more likely to cause problems for your baby if it happens in the early part of pregnancy. You also can pass CMV to your baby during labor and birth and during breastfeeding. If your baby gets the virus during these times, he’s less likely to have health problems than if he gets the virus during pregnancy.

About half of all pregnant women have had CMV in the past. If you’ve already had it, you don’t need to worry about getting it again. Once you’ve been infected, CMV stays in your body for life. You can still pass it to your baby, but this is rare and usually doesn’t cause any harm to your baby.

How do you know if you have CMV?
Most people with CMV have no signs or symptoms. But some may have:

  • A sore throat
  • A fever for a few days
  • Swollen glands
  • Fatigue (feeling tired all the time)

Tell your health care provider if you think you may have CMV. Your provider can give you a blood test to see if you have it.

If you have a weak immune system, CMV can cause serious health problems, including pneumonia or eye infections. For example, CMV can cause these kinds of problems for people with HIV.

How is CMV treated during pregnancy?
If your blood test is positive for CMV, your provider can test your baby for the virus using amniocentesis (also called amnio). During this test, your provider pushes a thin needle through your belly to remove a small amount of amniotic fluid. Amniotic fluid is the fluid that surrounds your baby in the womb. A lab tests the fluid for CMV. Your provider also may use ultrasound to check for physical signs that your baby is infected. An ultrasound uses sound waves and a computer screen to make a picture of a baby in the womb.

Scientists are working to develop a vaccine for CMV. They’re also looking for other ways to prevent babies from being born with CMV.

How do you get infected with CMV?
You can get CMV by coming in contact with bodily fluid from a person who caries the virus. Bodily fluids include saliva, breast milk, semen, mucus, urine and blood.

Women usually get infected by having sex with someone who has CMV or by having contact with young children with CMV. As many as 7 in 10 children (70 percent) between 1 and 3 years of age who go to day care may have CMV. They can pass it on to their families, caretakers and other children.

You may be more likely than other people to get CMV if you:

  • Have young children at home
  • Work with young children, for example as a child care worker or a teacher
  • Work in health care. If you’re a health care worker in contact with people who have CMV, including newborns, use standard precautions to keep from getting infected yourself. You may want to get tested before pregnancy to see if you’ve had CMV.

How can you protect yourself from CMV?
Here are some things you can do:

  • If you’re around children, wash your hands well after being in contact with their body fluids. For example, wash your hands after changing diapers, wiping noses and picking up toys.
  • Carefully throw away used diapers and tissues.
  • Don’t kiss young children on the mouth or cheek.
  • Don’t share food, glasses, cups, forks or other utensils with young children or with anyone who may have CMV.
  • If your partner has CMV, use a latex condom during sex.

More information
cmvfoundation.org

stopcmv.org

Last reviewed November 2012

Most common questions

What is mononucleosis?

Mononucleosis (also called mono) is an infection usually caused by the Epstein-Barr virus (EBV). It’s sometimes caused by another virus called cytomegalovirus (CMV). EBV and CMV are part of the herpes virus family. Mono is most common in teenagers and young adults, but anyone can get it. Mono is called the “kissing disease” because it’s usually passed from one person to another through saliva. In addition to kissing, it can also be passed through sneezing, coughing or sharing pillows, drinks, straws, and toothbrushes.

You can have mono without having any symptoms. But even if you don’t get sick, you can still pass it to others. Symptoms can include:

  • Achy muscles
  • Belly pain
  • Fatigue (feeling tired all the time)
  • Fever
  • Sore throat
  • Swollen glands in your neck

If your symptoms don’t go away or get worse, tell your health care provider. He’ll most likely do a physical exam and test your blood to find out for sure if you have mono.

There’s no vaccine to prevent mono. There’s also no specific treatment. The best care is to take it easy and get as much rest as you can. It may take a few weeks before you fully recover.

Can Rh factor affect my baby?

The Rh factor may be a problem if mom is Rh-negative but dad is Rh-positive. If dad is Rh-negative, there is no risk.

If your baby gets her Rh-positive factor from dad, your body may believe that your baby's red blood cells are foreign elements attacking you. Your body may make antibodies to fight them. This is called sensitization.

If you're Rh-negative, you can get shots of Rh immune globulin (RhIg) to stop your body from attacking your baby. It's best to get these shots at 28 weeks of pregnancy and again within 72 hours of giving birth if a blood test shows that your baby is Rh-positive. You won't need anymore shots after giving birth if your baby is Rh-negative. You should also get a shot after certain pregnancy exams like an amniocentesis, a chorionic villus sampling or an external cephalic version (when your provider tries to turn a breech-position baby head down before labor). You'll also want to get the shot if you have a miscarriage, an ectopic pregnancy or suffer abdominal trauma.

I had a miscarriage. How long should I wait to try again?

Before getting pregnant again, it's important that you are ready both physically and emotionally. If you don't need tests or treatments to discover the cause of the miscarriage, it's usually OK for you to become pregnant after one normal menstrual cycle. However, it may take longer for you to feel emotionally ready to be pregnant again. Everyone responds differently to a miscarriage. Only you will know when you are ready to try to get pregnant again.

Are gallstones common during pregnancy?

Not common, but they do happen. Elevated hormones during pregnancy can cause the gallbladder to function more slowly, less efficiently. The gallbladder stores and releases bile, a substance produced in the liver. Bile helps digest fat. When bile sits in the gallbladder for too long, hard, solid nuggets called gallstones can form. The stones can block the flow of bile, causing indigestion and sometimes serious pain. Staying at a healthy weight during pregnancy can help lower your risk of gallstones. Exercise and eating foods that are low in fat and high in fiber, like veggies, fruits and whole grains, can help, too. Symptoms of gallstones include nausea, vomiting and intense, continuous abdominal pain. Treatment during pregnancy may include surgery to remove the gallbladder. Gallstones in the third trimester can be managed with a strict meal plan and pain medication, followed by surgery several weeks after delivery.

©2013 March of Dimes Foundation. The March of Dimes is a non-profit organization recognized as tax-exempt under Internal Revenue Code section 501(c)(3).