Researchers: Most `test tube' kids are healthy

SAN DIEGO, CA More than 3 million children have been born worldwide as a result of what is called assisted reproductive technology, and injecting sperm into the egg outside the human body now accounts for about 4 percent of live births, researchers reported Sunday at the annual meeting of the American Association for the Advancement of Science.

The majority of assisted reproduction children are healthy and normal, according to researchers who have studied them. These children do face an increased risk of some birth defects and of low birth weight, which is associated with obesity, hypertension and Type 2 diabetes later in life, the researchers said.

According to Carmen Sapienza, a geneticist at Temple University School of Medicine, researchers found differences in 5 percent to 10 percent of chromosomes between assisted reproduction children and other kids.

What's not clear is whether these differences result in some way from assisted reproduction techniques or if they stem from other factors, perhaps ones that caused the couple's infertility in the first place.