Cytomegalovirus (si-to-MEG-alo-virus), or CMV for short, is a common virus that belongs to the herpes virus family. It can be passed between people through close and prolonged contact with bodily fluids such as saliva and urine. It is harmless to most healthy children and adults, and pretty much unknown to most people. Many people come into contact with CMV during childhood and it is thought that 50-80% of adults in the UK have been infected. As with other herpes viruses, once a person has been infected, CMV is “persistent” - in that it stays in the body for life and can occasionally be reactivated.
Whilst in most cases CMV will cause no, or very mild cold-like symptoms, CMV does pose a risk to pregnant women and their unborn babies, as well as people with low immunity.
Research shows that pregnant women most commonly acquire a CMV infection through exposure to the bodily fluids of young children (because young children are very adept at spreading their bodily fluids around!), especially their own.1 If a woman has had a previous CMV infection, it can become reactivated through this exposure. The CMV infection can then be passed to the woman’s unborn child via the placenta. This is known as congenital CMV and it can lead to miscarriage, stillbirth or serious birth defects.
It is estimated that 2-3 babies a day, or almost 1,000 babies a year, are affected by the CMV virus - it is the most common infection passed from mother to baby before birth.2 The majority of babies infected with congenital CMV will not have any symptoms at birth and will not suffer any long-term problems. However, CMV can cause disabilities and physical impairments, behavioural and learning difficulties and is the leading cause of non-genetic hearing loss.3