22 February 2010

IVF-linked chromosomal modifications prompt warning

by Kate Melville

Geneticists are recommending more rigorous health monitoring of IVF babies in later life as new research reveals links between assisted reproduction technologies and predisposition to certain diseases. More than three million children have been born as a result of assisted reproductive technologies since the birth of the first "test tube baby" in 1978, and while the majority of these children are healthy and normal, as a group they are at greater risk of certain kinds of birth defects and being low birth weight, characteristics associated with obesity, hypertension and type 2 diabetes.

Carmen Sapienza, a geneticist at Temple University School of Medicine, studies the impact of the environment on genes by comparing one type of chromosome modification, known as "DNA methylation" between children conceived in the traditional fashion with children born as a result of assisted reproduction.

His analysis points to a link between assisted reproduction and certain medical conditions, but Sapienza cautions that the picture is still not entirely clear. "We found that 5 to 10 percent of these chromosome modifications were different in children born through assisted reproduction, and this altered the expression of nearby genes," he explained. "But we have not yet distinguished whether this is caused by assisted reproductive technologies or other factors such as the couple's infertility."

Because some of the affected genes are involved in the development of fat tissue and the metabolism of glucose, Sapienza believes it will be important to monitor these children long-term to determine whether they have higher rates of obesity or diabetes.

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Source: Temple University