Assisted reproductive technology (ART) is the collection of strategies to conceive a child, and includes a batery of actions available to those suffering from infertility. Fertility treatmens which occur entirely outside of the body are in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI). IVF is the fertilization of an egg by a sperm outside the body, while ICSI is a more specific form of IVF in which sperm is injected into the egg cell.
But are IVF and ICSI affecting the future health of children conceived that way?
In the process of performing IVF or ISCI, certain epigenetic changes in both egg and sperm take place. These effects can become amplified as organs and tissues develop out of manipulated parental cells and possibly affect the health of the future child.
Back in 2003 and we had magazines publishing reports and stories like: babies conceived via ICSI don’t face any more health problems than babies conceived by natural means, babies conceived via IVF are as healthy as others etc. Which is no wonder, given that numbers of babies born to reproductive technologies was exploding and the longest-running study to that date was reporting about children who was under the age of five. Researchers compared rates of various problems experienced by 541 children and came to the conclusion that there were NO major differences in birth weight, growth, total IQ, or motor development found between the children conceived with infertility treatments and those conceived naturally. However, even in this small sample of children, the rate of birth defects was 6.2% and 4.1% for ICSI and IVF babies, respectively, compared with 2.4% among naturally conceived babies (and the rates achieved statistical significance only when comparing ICSI children with naturally conceived children, not the IVF ones). Malformations were also more commonly seen in boys than in girls.
To date,about 5 million children worldwide have been born via IVF and ICSI. The first one are reaching the age of 30 and it becomes possible to answer questions about the longer-term effects of IVF and ICSI on a range of health issues.
Epigenetics is still a new field, but one that has amazing potential to change how we understand the embryonic development. Darwinian thought assumed that the genes of an organism are the sole basis of what we are are and can become (and I still remember sitting in biology classes and feeling terrified that we all might be determined by our genes…thank God this turned out to be a hollow dogma).
We know now, however, that the DNA changes a LOT, by being in constant interaction with the environment. Those alterations can too affect our lives (and some can also be inherited). There are a variety of environmental causes that could induce alterations in the epigenome and manipulations such IVF and ICSI definitely belong there.
Studies performed on animals suggest that IVF or ISCI is associated with epigenetic changes that increase risk of obesity and diabetes. But also in human embryos, as published in Fertility and Sterility in 2011 by Batcheller et al., artificial technologies were found to possibly be harming heart health of children conceived using these methods. Also this study agrees that different aspects of ART treatment cause epigenetic differences and that fetal growth and placental development may serve as mediators for the programs which ultimatelly will affect cardiometabolic health.
Several more studies suggested that IVF increases blood pressure in children born via this method. Given the robustness of the cellular manipulation like ICSI, I was not surprised that there were differences found in long-term health of the children conceived this way. But I did get very surprised to read that the results could actually be caused by the in vitro culture that the cells were placed in, not just the manipulation of ovary or sperm. In this study you can find out how IVF children that had different cell cultures showed a significant difference of 250g in birth weight, indicating that partially at least the medium itself was influencing these alterations.
Clearly there is more to find out about the effects of IVF and ISCI, but the data so far indicate that there are potential risks to long-term health of children conceived via reproductive technologies.
There is a good news, too: in general, IVF and ICSI are safe and babies born that way are healthy and grow into healthy adults. To this, children born via IVF and ICSI tend to have moms and dads who are more committed to their role as parents than others, which remains THE best predicting factor for the future of the child.
- Batcheller, A., Cardozo, E., Maguire, M., Decherney, A., &Segars, J. (2011). Are there subtle genome-wide epigenetic alterations in normal offspring conceived by assisted reproductive technologies? Fertility and Sterility, 1306-1311.
- Yeung, E., &Druschel, C. (2013). Cardiometabolic health of children conceived by assisted reproductive technologies. Fertility and Sterility, 318-326.e4.
- Dumoulin JC, Land JA, Van Montfoort AP, Nelissen EC, Coonen E, Derhaag JG, Schreurs IL, Dunselman GA, Kester AD, Geraedts JP, et al. Effect of in vitro culture of human embryos on birthweight of newborns. Hum Reprod. 2010;25:605–612.