One September morning, Viktor Ahlqvist appeared live on CNN – side by side with US President Donald Trump. It was a scenario the researcher could never have imagined when, just a few years earlier, he began investigating the use of painkillers during pregnancy.

“I never thought I’d have to respond to a president’s statements in real time on American TV – and try to do it without swearing or burying my head in my hands,” he says with a laugh.

Viktor Ahlqvist is a postdoctoral researcher at the Department of Biomedicine and has, in collaboration with Karolinska Institutet in Stockholm, conducted one of the world’s largest registry studies on the use of paracetamol during pregnancy.

The study includes 2.5 million pregnancies and shows no association between the widely used drug and the development of autism in children – a link that has recently played a major role in political debates following a controversial announcement by the US government in late September.

Research suddenly became global politics

“It all started for us in 2023, when a research group issued a warning against taking paracetamol during pregnancy. We believed they had misinterpreted the data and decided to investigate the question thoroughly,” explains Viktor H. Ahlqvist.

He notes that Sweden has unique health registers, which also record over-the-counter medicines during prenatal check-ups. This made it possible to conduct a very comprehensive analysis.

Viktor Ahlqvist and his research team found that the small increased risk of autism development associated with paracetamol use, as suggested by earlier studies, disappeared when adjusting for fever and other factors. The results were published in 2024 and quickly became a reference point for researchers, authorities, and courts alike.

“We actually thought the project was finished. But the debate flared up again when American politicians used the paracetamol issue as part of a broader campaign about medicines, vaccines, and autism – casting doubt on the validity of our study. Suddenly, it all exploded,” says Viktor Ahlqvist.

Faced an unexpected and major communications task

The US Secretary of Health, Robert F. Kennedy Jr., and President Donald Trump put the alleged link between paracetamol and autism on the agenda at a large press conference in late September. In the weeks that followed, Viktor Ahlqvist and his colleagues were inundated with calls from international media.

“I was doing interviews almost around the clock with journalists from the US, UK, Sweden, and Denmark. We had to share press duties within the research group just to keep up, and I had to set aside nearly all of my other research work,” he says.

At the same time, Viktor Ahlqvist experienced how crucial science communication can be when political interests try to distort the facts.

“As researchers, we have three main responsibilities: research, teaching, and communication. When evidence is misunderstood or even misused to promote political agendas, we have a serious duty to clearly explain what our data shows and what it does not,” he says, and continues:

“But it’s always a balancing act. Every hour spent on interviews is an hour away from the lab – or, in my case, data analysis. But if we researchers don’t engage in the public conversation, we risk leaving the floor to people without scientific insight. It’s a difficult, but necessary, trade-off,” says Viktor Ahlqvist.

You can watch a clip of Viktor Ahlqvist live on CNN in the YouTube video here.

The University and colleagues were ready to help

Amid the intense media pressure, Viktor Ahlqvist received support from both the university, which helped handle the many press inquiries, and international colleagues who expressed their backing both in the media and privately.

“You don’t have to stand alone in a situation like that. There’s plenty of professional support available at universities, and I would strongly encourage people to make use of it,” he emphasises.

He also highlights how helpful it was when colleagues, independent experts, and health organisations, including the World Health Organization (WHO), publicly supported the research findings.

“It was a huge relief to receive so much support. It would have been a completely different experience if we had been left to defend the study alone against the US government,” he says.

Required ethical responsibility and public debate

For Viktor Ahlqvist, the debate also drew attention to how research can affect real people:

“When someone makes an official statement that a common medicine makes children ill, it creates immense guilt and fear among parents. Many mothers ask themselves: ‘Is it my fault that my child is autistic?’ And that’s deeply problematic when there’s no evidence to support it.”

He also points out that misinformation can have direct health consequences.

“If pregnant people avoid paracetamol due to misinformation or fear, they may end up using medicines with far greater risks for both child and parent. In the worst case, it can do more harm than good, both at the individual level and for public health more broadly,” says Viktor Ahlqvist.

From medication to genetic patterns

Although the large paracetamol study still dominates his calendar, Viktor Ahlqvist now works with statistical genetics and precision psychiatry at the Department of Biomedicine. Here, he investigates why people with ADHD and autism have an increased risk later in life of developing diseases such as ALS and Parkinson’s.

“I’m still trying to understand the same mechanisms – just across the whole lifespan, and not just during pregnancy,” he explains.

Looking back, he describes the past few months as both exhausting and enlightening.

“I’ve never worked so hard, but I’ve also learned how important it is for researchers to dare to explain their work even when it becomes political. We must not leave the public conversation to those who shout the loudest,” he says.

He hopes the attention to this area of research may also have a positive impact.

“If there’s one good thing Trump has done for my research, it’s reminding us all how important it is to have robust systems for monitoring the safety of medicines during pregnancy. Here in the Nordic countries, we have some unique opportunities and a responsibility to use them.”

Contact

Postdoc Viktor Ahlqvist
Aarhus University, Department of Biomedicine and
Karolinska Institutet
Phone: +46 704045347
Email: viktor.ahlqvist@biomed.au.dk