The Maori Select Committee inquiry into how to improve the lives of Maori children has finished hearing submissions and is focussing on compiling a report for Parliament.
Women's Refuge and anti-smoking groups have been among the submitters at four hearings held since June.
Murray Trenberth of Well Trust Youth Alcohol and Drug Services on Wednesday told the final inquiry that there should be intervention to improve the welfare of children.
He said education for expecting parents should become mandatory.
Mr Trenberth said parents should attend antenatal classes, but within the first three years of a child's life - his or her parents should be required to go to agencies such as Plunket or Tamariki Ora.
Mr Trenberth says his idea would be costly in the short term, but would provide good government savings in 20 years or so.