As a parent or soon-to-be parent of an IVF-conceived child, have you ever worried about the differences in your child’s DNA caused by IVF? Rest assured that while in-vitro fertilization and other artificial conception technologies cause small differences in DNA directly after birth, recent studies from the National Institute of Health and other organizations have shown that these differences largely disappear by late childhood.
To examine whether IVF-conceived children’s DNA differs from naturally conceived children’s, multiple studies have analyzed their subjects’ DNA methylation levels. Deoxyribonucleic acid (DNA) methylation is a tool used by cells that affects how certain genes develop and present themselves. The addition of methyl groups to a gene causes it to turn off, disabling it from producing proteins. These methyl groups fluctuate in genes throughout every person’s lifespan, but they can also fluctuate heavily at any step of IVF.
Dysfunctional methylation levels can be caused by certain diseases, and a possible result of these diseases is passing erroneous methylation levels down to offspring. Issues with methylation have been linked to improper embryonic development, chromosome instability, and other genetic diseases, according to an article from Nature.com.
Early studies had shown links between IVF and rare genetic disorders, perhaps caused by inadequate methylation levels, but these studies were conducted with few subjects and had inconsistent results.
A study published in April 2021 by the National Institute of Health, led by Edwina Yeung, Ph.D, had promising results that supported there being little difference between DNA produced by IVF.
Yeung’s study utilized 855 newborns and 152 children around age nine from New York State, with some being conceived naturally and others through assisted reproductive technologies. Their DNA methylation levels were measured and compared to see whether there were differences between methylation levels in the types of conception methods.
The results of this study showed that in newborns conceived through IVF specifically, there were lower levels of methylation in some segments of their DNA. However, the older children conceived through IVF in the study showed lower methylation levels for only one gene called GNAS.
The data from this study conveys that low methylation levels in IVF DNA are largely eliminated by early childhood, except for the GNAS gene.
Another study published by Genome Medicine in 2017 also evaluated whether IVF produced lower levels of methylation in children. This study differed from its counterparts because of the use of newborn twins instead of randomized individual subjects. Twins that were conceived naturally and through IVF had blood samples taken at birth, which were then assessed for abnormal methylation levels.
The data supported that methylation levels were notably lower in IVF twins compared to the naturally conceived group, but that these levels were only abnormal in a handful of specific genes. Twins were used in the study to eliminate potential environmental factors influencing the methylation levels, but the results were ultimately inconclusive. The researchers concluded that the correlation between IVF and low DNA methylation was not strong enough to suggest a relationship and that the low levels could be attributed to a number of other factors for the subjects.
The study acknowledges the variability of its results, as well as pointing out the possible misjudged conclusions of other studies. While almost all studies that analyzed this topic found that infants conceived through IVF had lower levels of DNA methylation at birth, this result could be attributed to parental fertility issues and other environmental factors. Only by conducting a greater number of more varied studies can the relationship between DNA methylation levels and IVF-conceived offspring be better understood.
While recent research has supported the belief that children conceived through IVF and ART have little to no differences in their DNA compared to their naturally-conceived counterparts by the time they reach early childhood, more research is necessary to better understand the effects ART processes have on embryonic development and other health issues.
Some earlier studies have discovered other health risks that come with IVF conception, including the development of heart problems like high blood pressure, blood vessel rigidity, and insulin resistance later in life, according to an article from TheConversation.com.
Additionally, an article from UCLA Health discusses how IVF may “significantly increase the risk of birth defects,” citing potential issues with the “eyes, heart, reproductive organs and urinary system” in children not conceived naturally. The article cites a UCLA study that found IVF infants were about 1.25 times more likely to have birth defects compared to naturally conceived babies.
While this may seem troubling, many doctors state that the benefits of IVF outweigh the possibility of these health defects. Many of the studies mentioned previously, both about DNA methylation and health risks associated with IVF and ART, are the first of their kind. Data on the effects of IVF on infants, and whether those effects follow children throughout their lives, is still in its infancy and has room for error.
Ultimately, despite the relieving data showing that DNA of IVF children may be indistinguishable from naturally conceived DNA and the upsetting data conveying that there may be elevated health risks when using IVF for conception, it is always best to talk to health care professionals when assessing the risks of assisted reproductive technologies.