Childcare use in the first year of life has no discernible bad effects, according to a series of Australian studies that track children through to age eight or nine.
Early use of centre-based childcare in particular has long been a contentious issue.
The associate professor of early childhood at Charles Sturt University, Linda Harrison, said the latest findings were ''good news for parents''.
The research will be presented today at the Australian Institute of Family Studies conference.
It shows that among two- and three-years-olds in childcare centres, no differences in behaviour or adjustment were apparent between the children who had started formal care as babies and those who had started later after having been at home with a parent or other carer.
''There were no discernible differences between the two groups after taking into account factors such as the socio-economic status of the families,'' Dr Harrison said.
Based on thousands of children tracked in the Longitudinal Study of Australian Children, the study used nine measures to examine how the two- and three-year-olds were faring.
These included how the children got on with other children, and with childcare workers, the level of problem behaviours, and how much they appeared to enjoy their activities.
The findings were based mostly on reports by teachers as well as by parents.
A significant difference between the groups was apparent on only one measure - boys who had been in a combination of centre-based and home care as babies tended to have more conflicts with childcare workers.
''But it is one finding out of nine,'' Dr Harrison said.
The study also tested whether longer hours in care were associated with worse outcomes. It found the more the toddlers were at the centre, the happier and more comfortable they were, but they also had more conflicts with carers.
A second study by Rebekah Levine Coley, a professor of developmental and educational psychology at Boston College, based on the Australian data, tracked the children through to age seven. It also found no detrimental effects from infant childcare. Children performed better at school if they had been in childcare at ages two and four. But behaviour problems among the four-year-olds were worse than among four-year-olds cared for at home.
''There are benefits and drawbacks of childcare at this age compared to parental care,'' Professor Coley said. ''Perhaps it's because of larger group sizes and fewer teachers.''
A third study found four-year-olds who went to a preschool or a preschool type program rather than a childcare centre had an initial significant cognitive advantage when they started school. But by age eight or nine, the academic skill advantage had disappeared.
''The biggest influence on children's academic achievement and behaviour remains family background rather than childcare,'' Dr Harrison said.