Many viruses can harm the developing fetus during pregnancy, but glandular fever, more commonly known as infectious mononucleosis, does not generally cause serious problems in pregnancy. Caused by the Epstein-Barr virus, mononucleosis, or mono, may make you feel tired and ill but does not increase the risk of birth defects or pregnancy loss, according to the Centers for Disease Control and Prevention. Talk to your doctor if you think you may have mononucleosis.
By the time a woman reaches reproductive age, most have already been exposed to the Epstein-Barr virus and have developed antibodies to it. Around 95 percent of people have antibodies to the virus between the ages of 35 and 40, according to the CDC, and the virus spreads through saliva. If you have antibodies to the virus, your baby has antibodies to the virus until maternal antibody protection wears off in several months.
Symptoms of mononucleosis in pregnancy do not differ from symptoms at any other time in life. Fever, extreme fatigue, swollen glands and sore throat occur most commonly. If the virus affects the liver, you may have yellowing of the skin and white of the eyes, upper abdominal pain and loss of appetite. If you develop swelling in your spleen, the organ could rupture, which is a medical emergency. Seek medical attention immediately if you develop signs of liver disease or abdominal pain. Take steps to keep your fever from rising too high, which could affect your baby. Sustained high fever of 103 Fahrenheit or higher could increase the risk of birth defects or fetal loss in the first trimester, according to Mary Lake Polan, an obstetrician who writes for the Baby Center website.
Because no medications are effective against the virus, you don't have to worry about treatments affecting your baby during pregnancy. Your doctor will advise 10 to 12 hours of sleep each night, no alcohol, no acetaminophen and a well-balanced diet, all treatments that will benefit you and not harm the fetus. Because most women already have some degree of fatigue in pregnancy, you may require even more rest. Eating well can be difficult when you have no appetite, but a good diet ensures that you will heal as quickly as possible and that your baby will get the nutrition she needs to grow.
The Epstein-Barr virus, which lies dormant in cells after an acute infection, can reactivate during pregnancy. A Norwegian study published in the September 2005 issue of "BJOG" showed that women with a significant reactivation of the virus during pregnancy had shorter pregnancies, 271 days compared to 279 days, on average. Epstein-Barr antibody status did not affect the rate of fetal death.