A study by Swiss researchers has found that children conceived through IVF or other forms of assisted reproduction are more likely to suffer from cardiovascular diseases that can have life-long health effects.

The study claims to be the first evidence that IVF has a long-term impact and that teens born through assisted reproduction were six times more at risk to develop clinically high blood pressure than those conceived naturally.

Researchers from the University Hospital in Bern say it could be due to the unmeasured impact of the techniques on the sperm and egg stored in an artificial medium and manipulated to form an embryo.

This study was small, with fewer than 100 subjects, but it follows data from animal tests which found blood vessels and heart abnormalities were more common with mice born through IVF, which has sparked calls for much larger safety trials.

“There is growing evidence that artificial reproduction techniques (ART) alters the blood vessels in children, but the long-term consequences were not known,” The Independent quoted Dr Emrush Rexhaj, a blood pressure expert and lead author of the study, as saying.

“We now know that this places children [born through artificial reproduction] at a six times higher rate of hypertension (high blood pressure) than children conceived naturally.”

“This is the first demonstration of increased prevalence of a cardiovascular disease [in children conceived through IVF],” Dr Rexhaj said.

But he said a 2014 study has suggested these patients may also be more at risk of Type 2 diabetes, adding: “There is already evidence showing insulin resistance in this population.”

Larger trials would be needed to conclusively show a health risk, experts say this should be considered urgently as the population born through IVF and other techniques is growing rapidly with the earliest births now in middle age.

There are an estimated six million people alive who were conceived with artificial reproduction techniques worldwide and in July, Louise Brown, the first child born through IVF, celebrated her 40th birthday.

For the study, published in the Journal of the American College of Cardiology, Dr Rexhaj recruited 97 healthy young people with an average age of 16 with 54 of the subjects having been born through IVF.