The Well Child book - the successor to the iconic "Plunket book" - has been given a revamp.
The new-look baby book was unveiled by Health Minister Tony Ryall at the Johnsonville Plunket Centre yesterday and will now be given to parents.
First-time mum Jessi Chen said the book provided invaluable advice when it came to her identical twins, 5-month-old Ella and Grace Gao.
"I love these books, it's really exciting to see your baby's growth and that they are healthy and happy."
Ms Chen said that 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.
The books were also a great resource for mums to share with one another, and compare their children's growth and development, she said.
The roles of partners and fathers play a larger part in the new edition.
Father of five Simon Gallagher said it was great for dads to have a chance to get involved as well as mums.
He said it was great to be able to look back through his other children's books and compare them with the progress of his youngest, a 10-month-old daughter.
The chief adviser of child youth health for the Ministry of Health, Doctor Pat Tuohy, said transforming the book was a lot of fun.
The new edition, the most substantial revamp in 25 years, is 100 pages longer, and has more tips for parents.
Included is information about oral health, speech and language issues and cot death or Sudden Unexpected Death of Infants (SUDI).
Dr Tuohy said there had been a lot of changes in health services and the way children were looked after in New Zealand, and for that reason it was time for a change.
Mr Ryall said the books were special because they allowed parents 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."
Plunket and Well Child books have been given free to all parents since the 1920s, and provide a record of their child's health and development.