Azad - CHILD study  

This study was initiated back around 2009, and the goal was to recruit families that were pregnant and then to follow the families and their new baby over time as those children grew up. And the original question to motivate the study was, why do so many more kids in today’s generation have allergies and asthma than in the past?  

We know there’s a genetic component because conditions like allergies and asthma do run in families. But we also know that’s not the answer to this epidemic. Our genes haven’t changed in a couple of generations. So what has changed is our environment, but a lot has changed in our environment. 

So in this study we wanted to do a really thorough job of capturing as much information, about as many elements of the environment as possible, starting from in utero. And so there was collection of information from the mothers during their pregnancy. So what they were eating, how they were doing health wise, both physical and mental health. And then once the babies were born, we captured biological samples. So cord blood from when they were first born, their first diaper, we captured breastmilk samples which have become a passion of mine to understand. 

We also had staff from the CHILD study, go out to each family’s home to collect dust samples to measure different chemicals and microbes. Look at all the types of furniture in the house and how many windows are there and what kind of cleaning chemicals to really understand that indoor environment, because babies spend up to 80% of their time in the first year inside their own home. So that’s a really important environment to understand. But then also the broader environment, the outdoor environment. So we’ve done measurements of traffic related air pollution near to each baby’s home, for example. We’ve also looked at social factors. So the social determinants of health and the socioeconomic status of different families, measures of parenting and stress. So really trying to get at all domains of the environment in these families.  

So altogether, there are 3500 families that are participating in the study. The children are born between 2010 and 2012. The study was funded by the Canadian government and initially it was funded to follow the children until they all turned five years old. These families are spread across four provinces in Canada. So the centers were Vancouver, Edmonton, Winnipeg, Manitoba, here where we are, and Toronto in Ontario. 

And so families were recruited from those centers. We were able to get additional funding to keep the study going. So we followed them again when the children were eight. And then now as we come out of the pandemic, the oldest kids in the study are turning 12. 

So we’re starting to follow them into adolescence and to study new topics like puberty onset as their children get older. So it’s really a treasure trove of information. There are well over 40 researchers across the country contributing to the study, and they come from all walks of science. So there is, of course, pediatricians and neonatologists, but also environmental scientists and nutritionists, people like myself who are interested in the microbiome. So it’s a really excellent team of scientists working to answer so many questions about child development and health.  

I think the overall message is that as we expected, what happens really early, so during pregnancy in the first couple of years, has a really strong relationship with how children develop later on.