Cytomegalovirus: The Virus All Pregnant Women Should Know About Now

Gail Demmler-Harrison, MD


December 02, 2016

Cytomegalovirus (CMV) is the most common virus that most people have never heard of and remains a neglected public health problem for women and children.[1,2,3] CMV infects 2%-4% of pregnant women for the first time as a primary infection during pregnancy, and it is transmitted to the fetus, resulting in a congenital infection in 40% of these pregnant women.[1,2,3,4]

Congenital CMV is well recognized as a common, endemic congenital infection, infecting over 30,000 newborns each year in the United States. Although many newborns congenitally infected with CMV may have no symptoms or sequelae, up to 8000 each year will have in utero growth restriction; petechiae; liver and spleen disease; thrombocytopenia; congenital and progressive hearing loss; vision loss; brain maldevelopment syndromes; microcephaly; and permanent neurodevelopmental and motor disabilities such as cerebral palsy.[1,2,3,4,5] In addition, fetal and neonatal death from in utero CMV occurs in approximately 400 babies each year.[1,2,3]

Yet, despite this well-recognized and well-accepted public health impact, only 9%-15% of women of childbearing age, including those with graduate degrees and those entering medical school, have even heard of CMV.[6,7,8,9,10,11,12,13,14,15,16,17,18]

Most people have by now have heard of the Zika virus, a potential epidemic threat to pregnant women and their babies that has many similarities to congenital CMV. This is because of a vigorous, strategized, education campaign by our local, state, and national public health officials, as well as pediatric and obstetric organizations, medical schools, clinics, and hospitals promoting Zika awareness and prevention strategies for all pregnant women. In addition, pregnant women are routinely counseled about HIV, rubella, and toxoplasmosis, which also may infect their unborn baby.[4] Meanwhile, year after year, CMV gets the silent treatment.

What can be done now to reduce CMV infection in pregnant women, thereby reducing CMV infection in the fetus and newborn?

The Knowledge Vaccine

A practical strategy is the "CMV knowledge vaccine," which has been proposed by CMV experts for decades and which can and should be "administered" and implemented now, to protect women from acquiring CMV during pregnancy.[19,20,21,22,23,24] The components of this "CMV knowledge vaccine" are simple: an ounce of CMV awareness and three simple precautions.

First, pregnant women must know that CMV exists before they can make a conscious effort to reduce their exposure and risk. Second, the recommended three simple precautions are based on the knowledge that toddlers and young children are "hot zones" for CMV and transmit CMV to their parents. Young children commonly, yet silently, excrete CMV in their saliva or urine for up to 1 year and will transmit the virus to 45%-53% of their parents within that year. Most infected parents will remain asymptomatic.[25,26,27,28,29,30] Furthermore, 9%-20% of CMV-seronegative women who work in day care centers with young children will acquire CMV infection.[4]

The three tips to reduce exposure to the most common sources of CMV involve:

  • Not sharing food, drink, straws or eating utensils with young children;

  • Not kissing young children on or around the mouth or lips; and

  • Washing hands well after changing all diapers (wet with urine or dirty with stool) and wiping runny noses or mouth drool.

Multiple studies have shown that CMV educational efforts directed toward women of childbearing age and those who are pregnant result in a significant reduction in CMV infections.[27,28,29,30,31,32,33,34] In one study, primary CMV infection was reduced from 42% in a control group of pregnant women who were not educated about CMV to 6% (P = .008) in the intervention group who were educated about prevention precautions.[29] Women also have also expressed positive attitudes toward CMV education and perceive CMV precautions as feasible.[15,35,36,37]

Despite this overwhelmingly positive information on CMV prevention methods, less than one half (44%) of obstetricians surveyed in 2008 by the Centers for Disease Control and Prevention reported counseling their patients about CMV prevention.[38] In addition, the most recent American College of Obstetrics and Gynecology (ACOG) Practice Bulletin, published in 2015, disappointingly stated[4]:

Such guidelines may be difficult to implement because they often are considered impractical or burdensome. At present, such patient instruction remains unproven as a method to reduce the risk of congenital CMV infection.

By taking this stance, ACOG denies the factual evidence that women welcome information on CMV prevention methods and do not find such information "burdensome or impractical." Furthermore, such paternalistic attitudes rob women of their power over their own reproductive health.

Frustrated by the lack of CMV awareness and education provided by the medical community, families affected by CMV have strived to promote CMV education through nonprofit organizations, websites, blogs, and social media.[39,40,41,42,43] In addition, these motivated families and friends, have addressed the public health problem of CMV through public policy and legislation. In five states (Hawaii, Illinois, Tennessee, Texas, and Utah), laws regarding CMV awareness have been passed that require healthcare providers to discuss CMV with pregnant women, and in eight additional states, CMV legislation has been proposed or is in discussion.[44] These efforts have resulted in public health initiatives and education programs aimed at disseminating information on CMV.

The greatest risk reduction strategy available now to prevent CMV transmission to pregnant women is education about CMV. Patients; healthcare professionals, especially obstetricians and midwives; and public health agencies should be partners in providing women with factual information and allowing them to make informed choices regarding their pregnancy health and prevention of CMV. In other words, spread the word, not the virus.


Comments on Medscape are moderated and should be professional in tone and on topic. You must declare any conflicts of interest related to your comments and responses. Please see our Commenting Guide for further information. We reserve the right to remove posts at our sole discretion.