Genetic Differences for 'Test Tube' Babies?
Researchers Look for Clues to Health Risks in Babies Born via Assisted Reproductive Technologies
Feb. 22, 2010 -- Babies born via IVF and other assisted reproductive technologies (ART) have more genetic differences than do babies conceived naturally, according to a researcher, although the majority of the ''test tube'' babies he studied are still within the normal range.
''There's not a big difference between the two groups of kids, so it's comforting," says researcher Carmen Sapienza, PhD, professor of pathology and laboratory medicine and acting director of the Fels Institute for Cancer Research at Temple University Medical School in Philadelphia. He presented findings from his study at this week's American Association for the Advancement of Science annual meeting in San Diego and published his findings in Human Molecular Genetics.
The information, as it evolves, should help parents of ART babies -- and the children themselves, as they mature -- stay aware of any additional health risks associated with the genetic differences and take preventive action, Sapienza tells WebMD.
Since the first ''test tube baby'' was born in 1978, more than 3 million children have been born with the help of ART.
Health Risks of ART Babies
Experts have known that as a group, ART children are at greater risk for some birth defects and for being born at a low birth weight, which in turn is associated with risks for obesity, high blood pressure, and type 2 diabetes later in life.
So, Sapienza and his colleagues looked at samples of placental and cord blood DNA from 10 ART children and 12 children who had been conceived naturally. The researchers were looking for differences in the levels of DNA methylation -- a type of modification that turns genes on and off.
Turning on a particular gene, Sapienza says, may be linked with a higher risk for disease -- for instance, a gene that controls glucose metabolism, when turned on too much, may be associated with type 2 diabetes.
First, researchers looked at the DNA methylation marks in 800 genes in the two groups of children, Sapienza says. "What we found is between 5% and 10% of the genes have significant differences between the two groups in the methylation, depending on whether we were looking at placental or cord blood."