Scientists have warned against the risks of intensive IVF treatment as research suggests it increases the risk of heart disease in children.
The “high stimulation” method, where powerful drugs are used to stimulate egg production, is a commonly used practise in British fertility clinics.
But experts are now claiming there is growing evidence the treatment can result in offspring with higher blood pressure and thicker arteries than normal.
Those traits among babies raise the risk of heart attacks and strokes as adults.
The warnings will be presented this week at the International Society for Milder Approaches to Assisted Reproduction conference in London.
They are based on a study comparing 65 Swiss pre-school children who were born from fertility treatment to 57 who were conceived naturally.
It found that those in the former group tended to have “generalised vascular dysfunction”.
A second study analysing all UK births following fertility treatment showed slightly poorer health outcomes in offspring where more than 18 eggs were retrieved at once.
Dr Sherman Siber, an American IVF pioneer, told The Mail on Sunday: “Hyper-stimulation is crazy because you end up getting a lot of poor-quality eggs.”
The studies contribute to a growing body of evidence that harsh fertility regimes can be associated with poor health outcomes in children.
Approximately 66,000 Britons were conceived through IVF.