Making sure pregnant mothers see a doctor within 10 weeks of conception should be a national priority, say MPs working to improve children's health.
A parliamentary committee behind an inquiry into child health and prevention of child abuse found that in parts of New Zealand, the proportion of women having antenatal checks was "Third World" - as low as 17 per cent in south Auckland.
The committee heard about high teen pregnancy and unplanned pregnancy rates, and recommended an overhaul of sexual and reproductive services including improved access to contraception and mandatory sexual education in schools.
It made bold recommendations to combat alcohol abuse by pregnant mothers, including requiring "unequivocal" warning labels on beer, wine and spirit bottles.
It also recommended that the Ministry of Health create a target to ensure 90 per cent of pregnant women booked an antenatal assessment within 10 weeks of conception.
The committee's report, published yesterday, sends a strong message to the Government that it should shift its focus and funding to the period between preconception and three years of age for the greatest social and economic return.
The proposal for a new health target was prompted by a review of the Counties Manukau region.
Only 16.8 per cent of women in the region sought maternity care within the first 10 weeks of pregnancy, and 86 per cent of pregnant Pacific Island women were obese or overweight.
The report said the rationale behind the 10-week target was that the earlier in pregnancy medical and social assessment happened, the sooner intervention could occur if required.
Health committee chairman Paul Hutchison said: "Early intervention, early booking in - we're Third World right now. We've got to give it a crack."
The period between preconception and early pregnancy has been identified in New Zealand and international research as a crucial window of development which influences the remainder of a child's life.
The Prime Minister's science advisor, Sir Peter Gluckman, told the Herald: "There is a growing focus in the community of scientists, doctors, clinicians, public health people who understand ... that the earlier in the life course one can address and optimise the health of both mother and father, the more likely the better outcome for the offspring."
Research by the Liggins Institute has found that a mother's pre-conception diet influences their future child's health.
Aucklander Lucia Tigri Brown, 24 weeks pregnant with her first child, said she was cautious after an earlier miscarriage and sought an antenatal check after 10 weeks.
"I think I was little bit more wary than the average woman, wanting to make sure everything was okay."
Ms Brown, 35, did not believe that the importance of an early pregnancy check-up was widely known.
"It is really important that women are getting the right knowledge."