The first "test tube baby" was born in 1978. With advances in reproductive science, an estimated one percent of all American babies are now born each year through in vitro fertilization --(IVF). But IVF and other assisted fertility treatments may be solving one problem by creating another, suggests new evidence from Tel Aviv University.
In a recent study, Dr. Ditza Zachor of Tel Aviv University's Sackler School of Medicine reported a strong link between IVF and mild to moderate cases of autism. Her findings were presented last month at the International Meeting for Autism Research in Philadelphia.
According to her research at the Autism Center at the Assaf Harofeh Medical Center in Israel, which Dr. Zachor directs, 10.5% of 461 children diagnosed with a disorder on the autism spectrum were conceived using IVF, a significantly higher number than the 3.5% autism rate in the general Israeli population.
Other factors in play
While the study doesn't draw any definitive conclusions, it presents some urgent questions, says Dr. Zachor. "It's too early to make a serious deduction based on that evidence alone," she says, citing other birth-related factors in her study, such as low birth rate and prematurity. Dr. Zachor's ongoing research will attempt to separate out these risk factors to come up with more precise numbers for autism and other prenatal conditions in IVF.
The key may be "imprinting," a biochemical procedure during cell division which determines which genes will be selected or "expressed" in the embryo. Research into epigenetics -- changes in gene expression that occur without a change in the DNA sequence -- suggest that the malformations may be caused by imprinting abnormalities introduced into the embryo while it's in a test tube environment, says Dr. Zachor. One such disorder linked with IVF appears to be Angelman syndrome.
However, Dr. Zachor does not want to discourage infertile couples from undergoing IVF implantation, which most often results in a healthy child.
Age-appropriate fertility treatments