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Keeping Your Baby Safe from Congenital CMV

With newborn babies, there’s no shortage of worries. From wondering if they are eating enough, to what’s in that diaper, to childproofing the house, to knowing when to call the doctor — new parents have a lot to think about.

And it doesn’t help that some infections in babies can start even before birth, as is the case with congenital CMV. February is International Prenatal Infection Prevention Month, so now’s a good time to explore some of the basics of CMV and what parents can do to keep their babies safe.

A Common Virus That’s Under the Radar

CMV stands for cytomegalovirus, and it’s a lot more common than you might think. More than half of American adults have had a CMV infection by the time they reach 40. The good news is that most people who have it don’t get sick. The bad news is that once you’ve had it, it’s there for life.

If a mother gets CMV while pregnant, she can pass it on to her baby through bodily fluids, and that’s where it can be more problematic.

Virus infecting 4-week-old human embryo.

The Signs and Symptoms of CMV

Like many viral infections, congenital CMV doesn’t always act the same way in every person — or every baby. Some babies who have it will never show symptoms. Other babies can have severe health problems, including hearing or vision loss, and intellectual disabilities.

In babies who show early signs of CMV, symptoms can include:

  • Rash
  • Jaundice
  • A small head, or microcephaly
  • Low birth weight
  • Enlarged liver and spleen
  • Seizures
  • Damaged eye retinas

Blood sample with requisition form for cytomegalovirus (CMV) test

Testing Options for Both Babies and Mothers

Pregnant women can get a blood test to see if they’ve ever been infected with CMV, and that can help determine their risk of passing it on. (Pregnant women who already have antibodies are not likely to infect their unborn child if they’re exposed to CMV again.)

If a pregnant woman is experiencing a new CMV infection, her obstetrician can use amniocentesis to determine whether the fetus has contracted the infection. Dr. Carmen Beamon, Director of Maternal-Fetal Medicine for WakeMed Physician Practices says, “Amniocentesis is typically recommended if there is evidence of active primary maternal infection from blood testing for the mom and also ultrasound findings of fetal infection. At this time, there are no proven treatments to give the mother to reduce the chance for infection in the baby.”

If a newborn is suspected of having congenital CMV, simple testing can help confirm a diagnosis, using a newborn’s saliva, urine or blood. Dr. Beamon says, “Babies exhibiting a prenatal concern for CMV or babies that are very small at birth without a known reason are tested for CMV.” For accurate results, the testing needs to be done within three weeks of birth.

Treating the Virus and Symptoms

Treatment isn’t often necessary in adults who don’t have symptoms, but newborns — due to their immunity levels — may need treatment. Dr. Beamon says, “When we know that the baby has CMV before delivery, we monitor more closely with ultrasounds.”

Once the baby is delivered, antiviral medications can help treat the symptoms. Dr. Beamon says, “Antiviral medications help prevent long term effects of CMV, such as hearing loss.”

Keeping Congenital CMV at Bay

The best way to prevent CMV is by washing your hands regularly and practicing healthy hygiene. Because children are a common source of CMV, people who have frequent contact with young children can be at a greater risk of getting it. Pregnant women, in particular, should do their best to avoid contact with children’s tears, saliva and other bodily fluids.

Here are a few other practical tips:

  • Avoid kissing children under age 6 on the mouth or cheek; instead, kiss them on the head or give them a hug.
  • Do not share food, drinks or oral utensils (fork, spoon, toothbrush, pacifier) with young children.
  • Clean toys, countertops and other surfaces that come into contact with children’s urine or saliva.

Dr. Beamon says, “Routine screening of all pregnant women for CMV is not currently recommended. If a woman has an exposure to CMV and/or there are ultrasound findings in the baby that are concerning for CMV, then testing of the woman’s blood is then recommended.”