The Epstein-Barr virus is usually just called EBV. If you haven’t heard of EBV infection, you may be surprised to know that you have probably already had it, and still do. It may be somewhere inside you waiting to wake up and reactivate. EBV is one of the most common viruses that people get. It is a member of the very big family of herpes viruses. Just like the herpes virus that causes cold sores in your mouth, or a painful shingles rash, EBV can come back.
When EBV comes back, it is called reactivation. In most cases, EVB reactivation causes minor cold symptoms. You may hardly notice. But if your defense system is run down, EBV can come back as mononucleosis. EBV is a common cause of mono. If EBV reactivates and causes mono, you will notice.
EBV spreads through body fluids. That’s why mono is called the kissing disease. You probably had your first EBV infection in childhood. In children, this infection causes few if any symptoms. If you had symptoms, they were probably passed off as a minor cold. By age 18, over 80 percent of people will test positive for EBV infection. A blood test will show antibodies to the virus that you made when you had your first infection.
Is EBV More Common in Pregnancy?
Most pregnant women will have antibodies to EBV. An EBV infection can activate during pregnancy or it could be a first infection during pregnancy. There is no evidence that either type of infection is more common in pregnancy or triggered by pregnancy.
In a study of over 35 thousand pregnant women in Norway, reactivation of EBV occurred in less than 6 percent of women, which is about the same as in a population of non pregnant women. New EBV infection was even less common.
There may be a higher risk that pregnant women who have reactivation may go on to have mono, but this is probably due to the fact that one in four teens or young adults who have EBV reactivation develop mono. The risk may not due to pregnancy, but to the age when many women become pregnant.
What Are the Symptoms?
Symptoms of EBV reactivation infection are similar to a common cold. You may not have any symptoms. If you do, they could include:
- Sore throat
- Skin rash
- Swollen glands in your neck
Symptoms of mono are more severe and obvious. They include:
- Very sore throat
- Skin rash
- Headache and body ache
- Swollen nodes in the neck and armpits
- Extreme tiredness (fatigue)
- Swollen spleen or liver
There is no treatment for EBV infection or mono, other than rest and drinking lots of fluids. EBV infection usually clears up in 1 to 2 weeks. Mono may take longer, especially the fatigue.
Does Having Mono or EBV Affect Pregnancy?
Probably not. There have been studies on the effects of EBV infection during pregnancy going back to the 1980s. There is no evidence that infection causes loss of pregnancy or birth defects. Large studies are lacking, but the Norwegian study found that pregnant women with significant reactivation had a slightly higher risk of delivering babies earlier (about 8 days earlier) and had a slightly higher risk of delivering lower birth weight babies. 
The main impact on pregnancy is probably the addition of fatigue and other symptoms to the usual stress of pregnancy. Although rare, studies show that EBV may pass to a baby during pregnancy, or after pregnancy during breast feeding. This is not a big concern. Babies rarely have any symptoms from EBV infection, and chances are they are going to become infected sometime during childhood anyway.
What to Do About EBV
There is not much you can do to avoid EBV infection or reactivation. Keep your immune system healthy by getting plenty of sleep and eating well. If you know somebody who has been diagnosed with mono, stay away. EBV can be spread through close contact. That includes kissing, sneezing, sharing a toothbrush or drinking out of the same glass. Infection can also spread through sex.
If you are diagnosed with EBV or mono during pregnancy, the treatment is the same as for anyone else. It includes getting plenty of rest, drinking lots of fluids, and taking an over-the-counter medication for fever or headache. The safest OTC during pregnancy is acetaminophen (Tylenol).  The risk of EBV or mono during pregnancy is low. Let your pregnancy provider know if you have any of the symptoms. This infection should not be a significant risk to your pregnancy or your baby.