Let's talk about...Cytomegalovirus (CMV)
Our ‘Let’s talk about…’ blogs will focus on different pregnancy topics, highlighting the key messages for you and exploring the latest guidelines and research so you’re kept up to date.
This week we’re looking at CMV (cytomegalovirus).
What is cytomegalovirus?
It’s a common virus that can infect everyone regardless of age or gender. Once you have got it you will have it for life, although for most people it is symptomless with no long term effects.
How does it affect pregnancy?
Infected mothers can pass CMV to their unborn babies (congenital CMV) and although these babies are largely well with no symptoms, CMV can pose a serious risk to unborn babies and is one of the leading causes of hearing loss and disability in children.
Almost 1000 babies are affected by CMV in the UK each year
How is CMW transmitted?
Close and prolonged contact with bodily fluids such as saliva, urine, breastmilk, blood, faeces.
Via the placenta to a baby in utero, or to a newborn when giving birth or breastfeeding (very rare for babies infected this way to have any symptoms).
The main way pregnant women catch CMV is from small children’s saliva and urine.
*You can’t catch CMV by being in the same room as an infected person, there must be contact with bodily fluids
How can pregnant women reduce the risk?
Although there is no vaccine for CMV, the good news is that simple hand hygiene methods are extremely effective in reducing the chance of infection.
As the main mode of transmission to pregnant women is via saliva and urine from small children, the following steps should be taken:
do not share food, cups or cutlery with children
try to avoid getting saliva in your mouth when kissing a child
wash your hands for 20 seconds with soap and water after changing a nappy or contact with saliva (alcohol gel can be used if washing not possible)
wash all items which may have been in contact with a child’s saliva
There’s no need to avoid or to feel worried about interacting with children, being aware of these basic hygiene steps drastically reduces your risk.
How is CMV detected in pregnancy?
As CMV is often symptomless it is unlikely that you would know you had the infection. It is usually suspected during an ultrasound scan and then confirmed with a blood test.
Why is CMV not routinely tested for in pregnancy?
The UK Screening Committee does not recommend routine screening for CMV for the following reasons:
babies that develop CMV develop normally with no complications
different strains of CMV and tests are not able to distinguish between them to identify those which are harmful
no effective treatments at present
What if I have CMV in pregnancy?
If CMV is detected in your pregnancy you’ll be well supported by a team of doctors and nurses in the fetal medicine unit who will arrange for some extra scans and you may be offered an amniocentisis to see if the baby is infected.
only a third of women who catch CMV in pregnancy pass it to their babies
4 out of 5 babies born with CMV have no health problems
of those babies who do have symptoms, there is a huge range in the severity of these
babies born with congenital CMV will be closely monitored with brain scans, eye, blood and hearing tests, and depending on the infection some may receive antiviral treatment. You will have a dedicated paediatric team to support and guide you through this.
Research
Obviously the main focus is on developing a vaccine and treatment that is safe and effective, but at this time this is still a work in progress. A treatment called Hyperimmune Globulin is being investigated at present.
Further reading
Head to the CMVAction website for more detailed information
Take Home message…CMV can pose a serious risk for unborn babies, but as the main mode of transmission to pregnant women is via the saliva and urine of small children, simple hygiene steps can vastly reduce this risk and there is therefore no reason to feel anxious being around young children during your pregnancy.
