Before they were even born, 7000 Kiwi kids started being tracked by Auckland University researchers.
The Growing Up in New Zealand longitudinal study looks at what shapes children's development and how early interventions might give them the best start in life.
A key purpose of the study was to provide information to help inform policy and Government decision-making and insights have been gained into paid parental leave, immunisation, poverty, household safety, bullying, participation in early childhood education, and pre- and post-natal depression.
It is 10 years since the study started and the children, recruited from the greater Auckland, Counties Manukau and Waikato district health board areas, have turned 8 and 9.
The Government-funded study intended to follow the families until the children turned 21 but in 2016 National announced funding would be cut.
This week, Minister for Social Development Carmel Sepuloni announced $1.9 million would be injected back into the study to ensure the current round of data collection could go ahead.
The researchers behind the project, Associate Professor Susan Morton and Associate Director Professor Cameron Grant, have shared their most fascinating findings with the Herald on Sunday.
1. By the age of 2, children are using screens an average of two hours a day
Screen time has been a feature of almost all of the children's daily lives from infancy.
They are digital natives so the concept all screen time is bad does not fit well with this generation.
Greater use is associated with an increased likelihood of developing behavioural issues but the study has provided information about how to mitigate this.
It appears it may be the rules in place on the content and timing of the screen time, rather than the number of hours, that is more important in shaping behaviour.
2. Some families have moved house 12 or more times in less than five years.
This generation is highly mobile. Only one in three of all the children and their families has not moved house at least once during their preschool years.
Nearly half are in rental accommodation, and the pattern isn't changing over time.
Many of the homes the children are growing up in are damp and cold, and this is more likely in the rentals that 40 per cent of the children experience, than in private homes or social housing.
The information was provided to Government and was useful in changes to legislation relating to landlords ensuring the safety, warmth and security of rental properties where so many young children spend their earliest years.
3. More than 85 languages are spoken in the homes of preschoolers
A third of children were born to at least one parent who did not grow up in New Zealand, often because the parents moved here to give their children a better life than they had.
One in four of the study children are identified by their parents as Māori, one in five as Pacific, one in six as Asian, and seven out of 10 New Zealand European.
But mums and dads don't always agree about their child's ethnicity.
The way children report on their own identity and ethnicities across the group are expected to change over time.
Understanding the development of ethnic identity is vital to discovering why we see ethnic disparities in child outcomes, and what we can do to solve them.
4. In their first year of life one in four children live in a household with extended family members
It probably comes as no surprise the traditional nuclear family is no longer the only norm.
One in five children are living in an extended family environment when they start school.
Sole parents are rare, although the likelihood of this increases as the children grow older, and household structures change often for this generation.
Ten per cent of children experienced at least one change of caregiver during their first year of life.
5. Nearly 40 per cent of pregnancies were unplanned
This meant the opportunity to make behaviour changes such as stopping alcohol and smoking, and starting to take folic acid, were delayed for almost half of the mothers.
And whether a pregnancy was planned or not, nine out of 10 mothers did not take folic acid as recommended - starting before pregnancy then reducing after the first trimester.
And one in six took none in the perinatal period.
The study also found too many mothers, 13 per cent, are experiencing depressive symptoms in late pregnancy and that these are often untreated.
In the post-natal period, this number drops to 8 per cent, but about half of those are new cases - not the same mums who experienced depression while pregnant - and the other half have resolved.
Symptoms are more likely in mothers who are young or facing high levels of financial or relationship stress.
The answer could lie in earlier screening for maternal mental wellbeing to provide appropriate support to mums from birth and help give children the best start.
6. Dads get the baby blues, too
The study has found twice as many new dads experience depressive symptoms as men in the general population and these symptoms are more likely after their baby is born than during pregnancy.
This is the opposite pattern to mothers.
Fathers most at risk of depression symptoms either felt stressed or were in poor health, although post-natal depression was also influenced by relationship factors.
Although paternal depression could not induce harm to the fetus, it could still affect the psychosocial and cognitive development of their children.
7. Those first 1000 days are crucial
It is well recognised the first 1000 days of a child's life from conception to 2 are crucial.
Being exposed to persistent adverse environments, such as material disadvantage and poverty in early life, is associated with a less than ideal start to life.
The effects are multiple and include poorer health and wellbeing overall, less complete and timely immunisations, a greater likelihood of being overweight or obese by age 4½, more behavioural issues and being less prepared for formal schooling.
When it comes to immunisation, 92 per cent of children are fully immunised by age 2, although timeliness varies. By 4 the figure was 85 per cent.
Incomplete and late immunisations are associated with a greater risk of significant respiratory illness in early life.
Intentions for immunisation are high in pregnancy. Parents know the benefits and intend to pursue them. But in the post-natal period immunisation is more often delayed or even missed for second-born or later children and for those living in greater adversity.
The study has also found education is not the missing link here – the challenge is to provide services in a way that allows all parental intentions to become reality.
8. One in 10 children has been regularly picked on or bullied since the age of 2.
New Zealand teenagers experience very high rates of bullying (compared to other OECD countries) and the study suggests it starts early.
Just over a third of children had been bullied or picked on by other children by the time they were 4.
It was a frequent and persistent experience for some.
9. Persistent poverty is seen for one in 10 children in their first two years of life.
Family finances can be complex: by the time a baby's born, nearly one in five families are receiving income from four or more sources.
And mothers on leave from work tend to use a combination of maternity leave, annual leave and unpaid leave.
Growing Up in New Zealand has gathered data showing 40 per cent of families experience material hardship at any single point during those formative first two years.
When this occurs many make sacrifices like cutting household heating and buying cheaper food in order to pay for other things.
Both mothers and fathers hoped to take twice as much parental leave in the time immediately after their child was born as they were able to.
By 4½, 97 per cent of children spent time away from their parent, such as in early childhood education or organised home-based care.
10. Our capacity to understand and speak te reo Māori is growing
Only five per cent of study parents reported being able to speak te reo Māori when they were interviewed during pregnancy, but by the age of 2, 12 per cent of the children were reported to understand some.
About 10 per cent were reported to be regularly speaking te reo by 4½.