1.3 Relevance of the work

We all like our children to grow and prosper. The first 1000 days refers to the time needed for a child to grow from conception to its second birthday. During this period, the architecture of the developing brain is very open to the influence of relationships and experiences. It is a time of rapid change that lays the groundwork for later health and happiness.

Professionals and parents consider it necessary to monitor children’s development. While we can track the child’s physical growth by growth charts to identify children with signs of potential delay, there are no charts for monitoring child development. To create such charts, we need to have a unit of development, similar to units like centimetres or kilograms.

The D-score is a way to define a unit of child development. With the D-score, we see that progress is much faster during infancy, and that different children develop at different rates. The D-score also allows us to define a “normal” range that we can use to filter out those who are following a more pathological course. There is good evidence that early identification and early intervention improve the outcomes of children (Britto et al. 2017). Early intervention is crucial for children with developmental disabilities because barriers to healthy development early in life impede progress at each subsequent stage.

Monitoring child development provides caregivers and parents with reliable information about the child and an opportunity to intervene at an early age. Understanding the developmental health of populations of children allows organisations and policymakers to make informed decisions about programmes that support children’s greatest needs (Bellman, Byrne, and Sege 2013).