It was more than 30 years ago when the world greeted its first "test-tube" baby. Now, after years of study, researchers are finding few medical differences between these children and kids conceived in the traditional way.
More than 3 million children have been born worldwide as a result of what is called assisted reproductive technology, and they account for about 4 percent of live births today.
Researchers say the majority are healthy and normal. Still, these kids face an increased risk of some birth defects and of low birth weight -- and it's not immediately clear why that is.
The findings are being presented Sunday at the annual meeting of the American Association for the Advancement of Science in San Diego.