The answer, he reassures them, is nothing.
Babies will pick up viruses from time to time and there’s nothing you can do to avoid it. Actually it is a natural part of their development as it helps their immune system to mature.
Watch the video above to learn about the signs that your baby has a cold and things to watch out for - such as a fever, or difficulty breathing - which could mean your baby requires medical attention.
Baby 101’ is HuffPost UK’s parenting video series with paediatrician, Dr Keir Shiels, addressing topics mums and dads may face in their first year of being a parent. From colic to trapped wind, crying babies and their nappy contents, he answers some of the most common questions new parents have.