She said as a first time mum it was scary if the children were sick, and it was good to be able to check the book for advice.
Ms Chen said the books were also a great resource for mums to share with one another, and compare their children's growth and development.
The role of partners and fathers also play a larger part in the new addition.
Father of five Simon Gallagher said it was great for dads to have a chance to get involved as well as mums.
He said his 10-month-old daughter was his youngest, and it was great to be able to look back through his other children's books and compare her progress.
Chief Advisor of Child Youth Health for the Ministry of Health, Doctor Pat Tuohy, said they had a lot of fun transforming the book.
The new edition is 100 pages longer, and contains more information for parents.
Included in the new edition is information about oral health, speech and language issues and cot death or Sudden Unexpected Death of Infants (SUDI).
There have been a lot of changes in health services and the way children are looked after in New Zealand, and for that reason it was time for a change, Dr Tuohy said.
Mr Ryall said the books were special because they allowed parents to be able to reflect on previous experiences.
"These books are not just important health records they are family treasures that record a baby's first years of life.
"They are a fantastic resource and it is marvellous they have been updated."
The books have been given free to all parents since the 1920s, and provide parents with a record of their child's health and development.
