CMV: What every pregnant woman needs to know about this acronym

If you’re a pregnant woman living in America, chances are good that you’ve heard of the Zika virus. Maybe you’ve even cancelled a trip to Florida or South America in the hopes of avoiding any unnecessary risk to your unborn baby, as images of microcephalic babies constantly played across our screens last year. However, there’s a different virus that poses a much greater threat to unborn babies in the United States than Zika does, but only 9 percent of women have heard of it: Cytomegalovirus (CMV).

According to the CDC, CMV is so common that by age 40, over half of American adults have been infected with the disease during some point in their lives. Much like Zika, the virus does not pose much of a threat for those with healthy immune systems. Most healthy people will not experience any symptoms upon infection, but if they do, it may simply appear as an indiscriminate, mildly annoying virus, maybe causing a fever and/or sore throat. Once a person becomes infected, the virus (which is a member of the herpes family of viruses) remains in their body for the rest of their lives, where it may or may not cause recurrent symptoms.

For those with weakened immune systems, however, and especially for infants in utero, CMV can be much more serious. For unborn babies in particular, the virus can cause congenital abnormalities such as microcephaly and hearing damage. Currently, it is estimated that the virus affects nearly 40,000 infants per year in the United States, and it is the single most common virus with which American infants are born.

CMV is so common that 1 in 3 children will have contracted CMV by age 5, according to the CDC. Therefore, pregnant women with young children – especially those in daycare – are at an elevated risk for passing on the virus to their unborn babies. Because the disease is passed through bodily fluids, and especially saliva and urine, anyone changing the wet diapers or picking up the drooly toys of young children – so, essentially, your typical mom of little ones, or the average daycare worker – could be at risk for contracting the virus. And if the woman is pregnant, there is a 30-50 percent chance of passing CMV on to her unborn baby in the case of a primary (i.e., first time) infection.

So what is a pregnant woman with little ones – especially those in daycare – supposed to do to protect her unborn baby from CMV?

“All pregnant women should be aware of the possibility of CMV infection, but there are no actions that can completely eliminate the risk of exposure or transmission,” says Dr. Brian J. Burke, a board-certified family physician, who is a full scope practitioner at a local hospital on Guam. “In general, it is recommended that pregnant women practice good hand-washing hygiene. It’s especially important to wash your hands after exposure to soiled diapers or nasal or oral secretions from children, and especially those children who are in daycare. Pregnant women should also avoid kissing children under the age of six on the mouth or cheek.”

Dr. Burke also recommended that pregnant women refrain from sharing food, drinks, and utensils with young children, and that they carefully clean any surfaces or toys that come into contact with the saliva or urine of young children.

What should pregnant women look out for in terms of CMV symptoms?

“That’s tricky,” says Dr. Burke, “as a primary CMV infection may cause a mild febrile illness and other nonspecific symptoms, such as a runny nose, sore throat, muscle and joint aches, headache, and fatigue, which may not be clinically apparent in up to 90 percent of cases.” Another form the virus may take is that of CMV mononucleosis, which is characterized by long-lasting fevers, enlarged lymph nodes in the neck, fatigue, and sometimes a rash and sore throat – similar to EBV Mononucleosis, otherwise simply known as “Mono.” “However,” Dr. Burke states, “if a pregnant woman presents with a non-specific illness and rash, or a mononucleosis like illness, testing for CMV is recommended.”

So, fortunately, simple things like diligent handwashing and other hygienic practices can help – although not entirely – to protect pregnant women from CMV. And, if a woman presents with symptoms that may indicate CMV infection, testing for the illness is recommended. However, few pregnant women are counseled to do any of these things while pregnant, or even told about CMV and its associated risks. A 2007 survey by the American College of Gynecologists and Obstetricians (ACOG) found that only 44 percent of OBGYNs routinely counsel their patients about ways to prevent CMV, and as of a 2016 statement in the American Journal of Obstetrics and Gynecology, ACOG does not recommend routine screening of all pregnant women for primary CMV infection.

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As to why routine screening isn’t currently recommended, Dr. Burke explained that the major reasons for this are because 1) Detection of the infection is difficult, 2) In the event that a pregnant woman is infected, whether the baby will be affected and how is difficult to determine, and 3) No preventative vaccine or approved, reliable treatment yet exists for CMV infections (although there are experimental therapies available). Because of these reasons, there are also important ethical considerations for making CMV screening routine for all pregnant women: Just as some contraception and abortion advocates used the Zika epidemic in Latin America to push for more access to those controversial interventions in the region, some also advocate for pregnant women with primary CMV infections to be counseled on the elective termination of their pregnancies, due to the potential risk for a poor prognosis.

When it comes to CMV, “the bottom line,” says Dr. Burke, “is that whether or not a woman knows her CMV status prior to conception, it is unlikely to have a major impact on a pregnancy prior to signs of an active infection, and the clinical decisions will be unique for each pregnancy that may be affected by a CMV infection.” So, if you’re a pregnant woman – especially one with young children around – be sure to take the necessary precautions to protect yourself and your baby from infection, and don’t hesitate to contact your doctor if you present with CMV-like symptoms.