Generation R is a large-scale study whereby 10,000 young Rotterdammers who are growing up are followed over a longer period of time. Beginning with pregnancy, this generation taking part in the study come by once every four years for a thorough examination covering a wide range of areas. One hundred researchers have already obtained their PhD on the basis of these data and the research team also provides important advice for real-life situations. Generation R Next was launched in 2017 and the researchers recently received four million euros from the Dutch government.

As paediatrician and head of the research, Jaddoe leads the day-to-day activities. Data collection (‘occasionally something can go wrong when you see dozens of children with one of their parents every week’), planning (‘what do we measure and when’), ethics (‘everything has to go through the medical ethics committee’) and budget (‘where do we find funding’), all fall under his responsibility. “The aim is to follow this generation of Rotterdammers over a lifetime.”

What does it mean for you to be a member of the KNAW?

“The appointment was a huge surprise because I had no idea about the nomination. It is, of course, a great honour. The KNAW represents the conscience of research in the Netherlands. Of course, I hope to contribute to this over the coming years – it is a lifetime membership.”

Generation R started out because at the time, many groups of Rotterdammers were not being seen. How are things now?

“We at least have a better overview than we previously had. For example, obstetricians used to determine whether the growth of a child was normal on the basis of reference values for white Dutch children from the 1960s or 1970s. And that was if you were lucky. Far more often it was on the basis of studies from the United States. What we have learned is that there are major differences between ethnic groups in how children grow in the womb. Children with a Surinamese-Hindustani background are on average almost 300 grams lighter at birth than children with a Dutch background. Moroccan children, on the other hand, tend to be slightly heavier. This is not unusual; it is actually quite normal within their group.

“Another example is smoking: We know that it is harmful. When we start talking about it, people often start to roll their eyes, they’re already thinking: Oh, here we go again. But what’s more important is: Who smokes and why? As a general practitioner, you are able to do something with this information. We see that as many as 30 percent of Turkish women smoke and about 1 percent of Moroccan women do. These are huge differences. With this information, obstetricians or general practitioners who are seeing a Turkish woman who wants to become pregnant can bear in mind that they need to pay more attention to the issue of smoking.”

Is that really ethically responsible?

“It seems more politically correct to aim to treat everyone the same and disregard their backgrounds. But you don’t do people justice that way. People are not alike in all respects and unfortunately, they do not have the same opportunities to be healthy. They are exposed to different things in their environment and have different lifestyle behaviours. Therefore, you need to look in a more personal way at what is good for an individual. These individuals do better this way as well.”

In December you received 4 million euros from the Dutch Ministry of Health, Welfare and Sport. Why are you continuing with this study?

“The aim is to keep following this generation of Rotterdammers involved in our study over a lifetime. Why do some people in Rotterdam have work while others don’t? Why do some finish school while others quit? How will these young people raise their own children later on? How have they lived their working lives by the time they are sixty? There are plenty of questions that can only be answered by continuing to follow them.”

In addition, we’re starting a new cohort study: Generation R Next. One of the things we found out during the research carried out on the first group, is that the phase before the parents are expecting a child and the initial phase of pregnancy are both extremely important. We want to monitor that now too. From a non-medical perspective too, the psychological, sociological and pedagogical aspects.”

What, for example, is so important during this first phase?

“Of course, the most well-known example is folic acid. It is very important that you start taking it before you are pregnant to optimise the folic acid levels before you try to conceive. You reduce the risks of spina bifida and a low birth weight this way. This has been known for decades, but unfortunately only fifty percent of women in Rotterdam take folic acid according to the prescribed guidelines. We can’t seem to reach the rest.”

Are you able to keep the young people you are following on board? Do they still want to work with you?

“At the moment about two-thirds to three-quarters of the 10,000 participants are still participating in the project. That’s a lot, especially for projects like this. It is still a lot of fun in the beginning because parents get extra ultrasounds, but after that it takes a lot of effort. Then they discover: Uh-oh, the study goes on after the birth as well. Meanwhile, we have participants living in Groningen, Canada and South Korea. But for the time being, we can plan it in such a way that they remain being a part of it.”

Vincent Jaddoe 0516-033
Image credit: Levien Willemse

He laughs: “Until recently, we could rely on parents who would say to their children: ”Come on, join in.” We gave these parents an umbrella, a bike seat cover or a bag as a thank you. But now their children must decide for themselves. They are the ones who have to make time for it. We have shifted our focus on gifts to them. We might offer them a cinema ticket, for instance, and attempt to make it as engaging as possible for them with the help of electronic questionnaires.”

How unique is this project?

“What makes Generation R unique is the multidisciplinary approach. It is not only medically oriented but also sociologically, psychologically and pedagogically. And we hope that more EUR researchers will take part, especially as the children grow older. Maybe even the Faculty of Economics, or criminologists from the Faculty of Law. The fact that we are all housed together as researchers on one floor makes it even more unique. We meet once a week and discuss our progress, each from their own perspective. That brings a lot of added value.  Within the various disciplines, different ways of analysing data have crept in over the years and that’s how we learn from each other.”

How open to generalisation are the results? Or is the data mainly interesting for Rotterdam?

“We use the city as a laboratory. This is a Rotterdam project with wee ‘Rotterdammertjes’ and their parents, and it’s Rotterdam healthcare providers who are involved. However, there are around 150 nationalities taking part. This means that almost every group living in the Netherlands is represented, so this is also translatable to the rest of the Netherlands.”

What results are actually typical for Rotterdam?

“We see that Rotterdam has a lot of problems with air pollution. This has to do with cars, but certainly with the port as well, which is relatively close to the city in comparison with other port cities. We see that this air pollution has an effect on the growth of a child. Children grow more slowly then and are more likely to develop asthmatic conditions. One of the researchers addressed this issue during a council meeting. That’s good: On the one hand it is scientifically relevant, but in actual practice, a lot can be gleaned from our research. It is a case of and – and.”

What did you find particularly significant?

“Two elements. Firstly, how important the pre-conception phase is, which is also the entry point for Generation R Next. Secondly, how huge the enormous social and ethnic differences are in terms of health factors. These lie in behaviour, hearing, oral health, everything. Once again: We really should dare to identify these groups more clearly in order to be able to help them further. We ought not be too cautious where this is concerned. For example, we see that cavities are much more common in people with a Moroccan or Turkish background. Then you could ask: Is that significant? Yes, because oral health has lifelong consequences. Among highly educated Dutch mothers, you see that they tend to drink the most alcohol during pregnancy. Apparently, there is still work to be done there too.”

The main medical challenge is currently the coronavirus. Can you contribute to that with your research?

“Absolutely. Fortunately, so far not many children have been admitted with symptoms, but not enough is known yet for us to have any positive expectations regarding the future. It is also uncertain whether children with underlying conditions have a higher risk of developing serious issues. More knowledge is therefore needed about the influence of the virus on children. What is their immune system’s role, how does the virus spread to family members and what is the impact of this pandemic on families? What are the implications of governmental measures for a family’s lifestyle, health and well-being? We will be researching all of this over the next few months.”