CMV, or Cytomegalovirus, is a viral herpes infection that 85 per cent of people will acquire by the age of 40.

Many won’t show symptoms apart from those of a common cold or flu.

Rarely is it dangerous, except to unborn babies.

10 News+ presenter Amelia Brace sat down with baby Leonardo Pope’s mother – Sarah Pope – who has firsthand experience of how this common virus can impact a baby’s health and development.

Baby Leo was born at 40 weeks, a healthy three kilos, 60 grams and 50 cms long.

Sarah says he was developing well until he was around nine months old, when she started to realise he wasn’t reaching the same milestones his three-year-old sister had previously.

In Australia, blood spot screening is offered for all newborns to test for a range of medical conditions.

Those samples are stored for up to 18 years to retrospectively test for other congenital disorders or birth defects.

Doctors decided Leo’s sample needed to be re-examined and Leo was diagnosed with Cerebral Palsy – a result of Sarah contracting CMV during her pregnancy.

As Leo’s health improves in small milestones, Sarah wants more mothers to know about the risks of contracting CMV and how they can better protect themselves and their children.

Watch more from 10 News+ at 10.com.au