Women in prison are now able to keep their babies with them for longer, as a law change takes effect from Monday, 19 September.
The age limit for infants living in prison is now extended from nine months to two years.
Mother and baby units at Auckland Regional women's corrections facility and Christchurch women's prison open their doors this week, following construction and conversion work.
Plunket says the change is a step in the right direction, but says it should go further because international evidence shows the first three years of a child's development are crucial.
Some infant mental health specialists say splitting mother and child at the age of two has developmental risks and consequences.
The College of Midwives says the change is a rapid leap forward from an inhumane system to an inclusive one.
