The study, published in the Journal of the American College of Cardiology, tested 54 adolescents conceived with IVF or ICSI and compared them to 43 adolescents conceived without assisted reproductive technologies.
The researchers, based at the University Hospital of Bern, Switzerland, tested blood vessel and heart health, including 24-hour blood pressure monitoring. On average, blood pressure was slightly higher for the IVF and ICSI group, with eight individuals having clinically high blood pressure. In the control group, one person had high blood pressure.
'The increased prevalence of arterial hypertension in [IVF] participants is what is most concerning,’ said study author Dr Emrush Rexhaj. 'There is growing evidence that assisted reproduction alters the blood vessels in children, but the long-term consequences were not known.'
The researchers compared these results with tests they had done on these individuals five years previously. The measured differences had emerged over those five years, as originally they had found no difference in blood pressure and between the IVF and ICSI group and the control group.
Professor Robert Norman of the University of Adelaide, Australia, who was not involved in the study, said: 'It may be that the first few days of exposure of an embryo to artificial culture media may affect a number of developing organs, including the heart and blood vessels.'
Critics have said that this study was not large enough to distinguish other lifestyle factors that affect blood pressure. Alastair Sutcliffe, professor of general paediatrics at University College London, who was not involved in the research, noted that larger studies have found that IVF-conceived individuals are generally healthy, except for having a greater risk of the rare congenital condition Beckwith Weidmann Syndrome, and conditions associated with premature birth if they are born before term.
'Otherwise their health to date – for example with cancer risk – is no different than the population as a whole,' said Professor Sutcliffe.
Other researchers in the field have said that the preliminary findings warrant further investigation of the link between IVF and ICSI and cardiovascular conditions. Dr Larry Weinrauch, from Mount Auburn Hospital in Cambridge, Massachusetts, and who also was not involved in the study, said: 'We need to be vigilant in the development of elevated blood pressure among children conceived through assisted reproductive technology to implement early lifestyle-based modifications and, if necessary, pharmacotherapy.'