This study explores whether the likelihood that a child will develop autism or neurodevelopmental difficulties is affected by factors in their environment. 

 
We initially conducted a feasibility study in 2019 enrolling 100 mothers and their children aged 4-12 years to ensure that the proposed questionnaires and tests were acceptable and easily understood by the parents and their children. It allowed us to make adjustments to the protocol before proceeding to a larger (main) study.  

The main study followed (2020-2025), which included and enrolled 2000 children aged 6 to 15 years old and their caregivers. This study is called the Safe Passage Study–Biomarkers of Neurodevelopmental Outcome (SPS-BONO). It builds on a previous study in Cape Town, South Africa, South African Safe Passage Study (SASPS, or PASS for short) that involved 7000+ pregnant women.  Researchers followed them from before birth until the end of the child’s first year of life. This study did not focus on autism and instead considered the role of environmental risk factors in stillbirth and sudden infant death syndrome (SIDS). The factors that were found that can increase the risk of stillbirth and SIDS include infections during pregnancy, malnutrition, stress and trauma, cigarette smoking, alcohol and drug consumption.   
 
During the BONO-SPS, questionnaires were administered to the parent or child in person. Mothers or primary caregivers initially answered questions about their child’s environment, behaviour and emotional development. The children and their mothers also took part in cognitive tasks such as…. As the children got older, we administered questionnaires to them as well asked about any symptoms of anxiety or depression, and possible tobacco, alcohol and substance use. We also measured the children’s weight, height, head circumference and blood pressure. 

The children then took part in tasks on an electronic tablet that assessed their attention, responses to different types of rewards, social behaviours, and whether they showed any emotional and/or behavioural problems. Researchers measured the children’s brain activity using a technique called electroencephalography (EEG). This involves placing small sensors on a child’s head to record the electrical activity that their brains produce naturally. The sensors record but do not emit electricity and are painless. Children could play with toys or watch videos during the recording. During the second stage of the EEG, children took part in a task that tracked what they choose to look at most. 
 
Finally the brains of children and their mothers were visualised using a low-radiation magnetic resonance imaging scanner called the Hyperfine. The children provided saliva for genetic analysis which will be analysed together with maternal saliva specimens at the Pasteur Institute in Paris. 

The SPS-BONO study has produced useful data on the children’s behavioural, emotional and cognitive development that may provide insights into how early prenatal and other environmental factors can affect the likelihood of developing autism, other developmental conditions and emotional-behavioural difficulties. Some factors may increase this likelihood, while others may reduce it, even in those whose family members are autistic.

Part of the AIMS-2-TRIALS research involved identifying biomarkers of autism in research projects involving European families. It is important to check that these biomarkers are useful in larger groups of people and in those from different backgrounds. Therefore, researchers may check that biomarkers identified in European studies also apply when tested in the South African participants.    

For more information see research paper here https://pmc.ncbi.nlm.nih.gov/articles/PMC13162464/