Ahem! What we mean is that being conceived in a dish versus the natural way can affect the methylation of your DNA.
Previous studies suggested that the less romantic method of putting sperm and egg together in vitro (assisted reproduction technology; ART) resulted in a higher risk of birth defects and rare disorders that involve imprinting. To test whether DNA methylation could be a factor, researchers at the Temple University School of Medicine, Illumina, and the U Penn School of Medicine compared the DNA methylation levels of placental tissue and cord blood from in vitro and in vivo human conceptions with a custom-designed methylation bead-array platform. Then, they assayed the expression of some of these genes.
Small, but significant, differences emerged. In general, placenta tissue from in vitro conceptions had lower levels of DNA methylation at CpGs, whereas cord blood had higher levels of methylation. Some of the differentially methylated genes also were differentially expressed.
Interestingly, there appeared no correlation between in vitro or in vivo conceptions and their methylation patterns while Barry White was playing in the background, but this variable requires further investigation.
Mull over all the data at Human Molecular Genetics, July 2009