ShanLyn, Ma; Falster, Kathleen; Banks, Emily; Lynch, John; Chambers, Georgina; Brownell, Marni; Dillon, Anthony; Eades, Sandra; Jorm, Louisa
Background Indigenous Australian children are twice as likely to score poorly on developmental outcomes at age
5 years than their non-Indigenous peers. Indigenous children are also more likely to be born to younger mothers.
We aimed to quantify the relationship between maternal age at childbirth and early childhood development outcomes
in Indigenous and non-Indigenous children.
Methods In this population-based, retrospective cohort study, we used data from the Australian Early...[Show more] Development
Census (AEDC) that were probabilistically linked by the New South Wales (NSW) Centre for Health Record Linkage to
several NSW administrative datasets, including the Perinatal Data Collection, the Register of Births, Deaths and
Marriages (for birth registrations), the Admitted Patient Data Collection, and public school enrolment records, as part
of the Seeding Success study. The resulting data resource comprises a cohort of 166278 children born in NSW whose
first year of school was reported in a 2009 or 2012 AEDC record (which were the years of AEDC data available at the
time of data linkage). The primary outcome was the aggregate outcome of developmental vulnerability (scores in the
bottom decile, according to the 2009 benchmark, on one or more of the five AEDC domains, which include physical,
social, emotional, language and cognitive, and communication development). This outcome was measured in singleton
children without special needs recorded on the AEDC, in those with available developmental data. As a secondary
outcome analysis, we also repeated the main analyses on the outcome of developmental vulnerability on the individual
domains. We estimated the absolute risk of developmental vulnerability by maternal age in Indigenous and nonIndigenous populations, and we also estimated the risk difference and relative risk between Indigenous and nonIndigenous children by use of modified Poisson regression.
Findings Of 166278 children in the cohort, 107666 (64·8%) children were enrolled in a public school in NSW in 2009
or 2012, of whom 7994 (7·4%) children were Indigenous (ie, they, or either parent, were recorded as Aboriginal or
Torres Strait Islander on one or more birth records) and 99672 (92·6%) children were not Indigenous. After exclusions,
the final study population included 99530 children (7206 [7·2%] Indigenous and 92324 [92·8%] non-Indigenous). Of
those for whom developmental outcome data were available, 2581 (35·9%) of 7180 Indigenous children and 18071
(19·7%) of 91835 non-Indigenous children were developmentally vulnerable on one domain or more. The risk of
developmental vulnerability decreased with maternal ages between 15 and 39 years, but the decrease in risk with
maternal age was significantly steeper in non-Indigenous than Indigenous children.
Interpretation Developmental vulnerability is most common in Indigenous and non-Indigenous children born to young
mothers; however, Indigenous children have an increased risk of this outcome across most of the maternal age range.
Policies that improve the socioeconomic circumstances of Indigenous children and families could promote better
developmental outcomes among Indigenous children. Culturally appropriate support for Indigenous children, including
those born to young mothers and disadvantaged families, could also reduce early childhood developmental inequalities.