Nieman: Awareness needed of damaging virus passed from mom to baby

When a woman is pregnant, we use the term “she is expecting.” This, of course, means she is expecting to have a healthy baby, ideally born at full term, in an uncomplicated manner, and then after that, most women hope to nurse a healthy baby.

Not so long ago, I met a couple who indeed expected the above and all went well until the baby failed his newborn hearing test. Suddenly their expectations pivoted from normal to fear; from hope to despair. Even as I listened to them describing their abrupt pivot toward an unexpected trajectory, I felt compassion as the mom broke down in tears sharing the family’s story.

Upon further investigation, it was determined that the cause of the deafness was due to an infection called cytomegalovirus (CMV). When a baby gets infected via the mom during pregnancy, it is called congenital CMV. The latter is responsible for 20 per cent of all deafness diagnosed during the newborn period.

CMV is the most common infection passed from pregnant women to babies. It? belongs to a family of viruses known as herpes tribe (Of course, in this family the most notorious is genital herpes and cold sores herpes. But the herpes family also is comprised of mononucleosis and chickenpox.) These viruses live forever in the body and become dormant,l they fall asleep, only to flare up under certain circumstances.

More than half of adults have been infected with CMV by age 40, but most don’t know they have been infected. It is spread via blood, saliva, breast milk, tears, urine, semen and vaginal fluids.

People who work in daycare settings and those having close contact with babies as health-care providers are at an increased risk of contracting CMV.

Saliva is easily shared when licking a soother “clean” after it dropped on a surface, or by sharing toothbrushes, foods, drinks, cups, straws or forks. These habits should be discouraged. As expected, handwashing after coming in contact with secretions reduces the risk of infection greatly.

If an expectant mom gets infected by CMV during her pregnancy, she will pass it to her baby in about 33 per cent of cases. If she was infected by CMV before she got pregnant, then the risk of passing it on is around one per cent.

Not all babies infected by CMV via the mom during pregnancy have symptoms at birth. If a baby does get infected and it is undetected, bad things can happen later; bad enough to traumatize parents and cost our health-care system millions of dollars.

One would think that if 0.6 to 1.2 per cent of newborns have been infected by CMV, our health-care system would screen babies’ urine routinely in the first three weeks of life. But that is not the case uniformly in Canada. In Saskatchewan, and some other provinces, babies are screened, but in Alberta that is not the case – yet.

Those who advocate for early detection are aiming to change the current situation from piecemeal screening to universal screening. (A terrific Canadian resource about CMV, and specifically congenital CMV, is www.cmvcanada.com and in the USA www.national.cmv.org

Undiagnosed congenital CMV can cause intellectual and developmental disabilities, smaller than expected head sizes, seizures, visual loss, poor growth, problems with the liver and spleen, pneumonia and purple splotches on the skin. The later rash looks like a blueberry muffin. These issues can require numerous specialists as layers upon layers of troubles unfold. Congenital CMV is the second leading cause of intellectual disabilities after Down Syndrome. About 25 per cent of hearing loss diagnosed by age four is due to CMV.

Ideally, early detection and early treatment can prevent later pathologies and anguish for parents who were unaware of the wide impact congenital CMV may have on what appeared to be a healthy baby at birth. Antiviral medication before the age of six months remains the gold standard, because the earlier the treatment after detection, the better the outcome.

General awareness of CMV during pregnancy by doctors and the public? remains below par and, for that reason, I recommend visiting cmvcanada.com or contacting the executive director, Kayla McNally (kmcnally@cmvcanada.com)

Recently I learned that research done at the University of Calgary also includes input from parents of babies with congenital CMV. Who better to provide input to a team working on solutions than parents who experienced it firsthand?

Dr. Nieman is a community pediatrician and the founder of Centre 70 Pediatrics. He has written monthly columns for the Herald since 1999. For more information, see www.drnieman.com