People conceived through in vitro fertilisation treatment should be monitored for the early onset of high blood pressure, diabetes and certain cancers before the age of 50, according to a fertility specialist.
While IVF is generally considered to produce healthy babies, doctors have identified subtle genetic changes that may raise the risk of particular medical conditions in later life.
Since the birth of the first test tube baby, Louise Brown, on 25 July 1978, more than three million babies have been born through fertility treatment around the world. The vast majority are still under the age of 30.
The extent to which IVF babies develop more hypertension, diabetes and cancer will begin to emerge over the next two decades as they enter middle age, doctors said.
"By and large these children are just fine, it's not like they have extra arms or extra heads, but they have a small risk of undesirable outcomes. What's going to happen to them down the line? Bear in mind none is older than 31-years-old," said Carmen Sapienza, professor of pathology at Temple University School of Medicine in Philadelphia.
"They have a much higher frequency of being low birthweight and this results in a higher tendency to be obese, a higher risk of type 2 diabetes and hypertension when you reach 50 years old," Sapienza told the annual meeting of the American Association for the Advancement of Science in San Diego on Monday.
In 2006, the Department of Health warned that Britain was facing a new wave of cancer on the back of increasing obesity in the population.
Obesity plays a role in 4% of cancers, including breast and womb cancer, and has also been linked to the disease in the bowel and kidney. In most cases, hormones released from fat are to blame.
"It makes sense for IVF children to watch out for hypertension, obesity and related diabetes and cancers as they reach their fifties," Sapienza said. "It will be interesting to monitor these children."