Currently in Spain about 150.000 In Vitro Fertilization (IVF) treatments are carried out per year and about 34.000 Artificial Insemination (AI). With these figures, today, around 9% of Spanish babies are the result of an Assisted Reproduction (RA) treatment.
However, there are many people who are respectful of resorting to fertility aid methods. Many times they argue that it is not something natural, that the machine is being forced and that, perhaps, if they cannot have children it is because it has to be that way.
But… Is this true?
Is there any scientific evidence that shows that having children via assisted reproductive treatment carries some risk compared to having them natural form?
The truth is that the processes of in vitro fertilization they are many times considered 'miracles' even by science itself. And, of course, they pose a challenge to the laws of nature. As such, it is also true that each face can have its tail.
Let's see what science says about it.
Studies on the risks of assisted reproduction
The studies that analyze the potential sequelae that children born through reproductive techniques could suffer are still not very concise. On many occasions, the groups are scarce, the data complex to compare and there are no studies with sufficient perspective to offer data related to the subsequent development of babies.
Almost all the studies conducted focus on complications at birth: intrauterine growth restriction, delivery complications, prematurity, low birth weight, small size for gestational age, increased malformations, and higher perinatal mortality.
Complications at birth
However, a large French study analyzed 162 IVF singleton pregnancies with 263 pregnancies resulting from stimulated (non-IVF) cycles and 5096 natural pregnancies.
No significant differences were found between the first two groups with respect to complications. But the results do indicate that these complications are more common for pregnancies after ovarian stimulation (with or without IVF) compared to natural pregnancies.
For this reason, it is believed that the increased risk does not appear to be related to the IVF method itself, but rather to other common factors in these two populations. That is, the characteristics of the population, the underlying infertile state along with ovarian stimulation.
In the case of higher prevalence of congenital malformations, it is believed that it is not due so much to the technique as to the characteristics of the parents who undergo them.
mild cardiovascular disorders
The studies with the greatest projection over time seem to confirm that the use of assisted reproductive techniques can lead to children with cardiovascular and metabolic disorders during adolescence or early adulthood.
In 2012, Swiss scientists, led by a team from the University Hospital of Bern, compared 64 children born with IVF techniques and 57 children conceived naturally and found that among the first group, 30% of the participants showed high pulmonary arterial pressure, aging premature vascular disease, increased blood vessel stiffness at high altitude, and increased risk of hypertension in adolescence.
Other researchers have since concluded that assisted reproductive technology induces intrauterine cardiac remodeling that persists until the child is around 3 years of age.
metabolic alterations
In the same study, researchers looked at 54 children conceived through IVF when they had a mean age of 16 years and compared them with 43 control participants with a mean age of 17 years.
Their blood lipid and high-sensitivity C-reactive protein levels were normal and comparable, as were their birth weight and gestational age.
In the study, maternal body mass index, maternal smoking, and overall maternal cardiovascular risk profile were also similar. However, the young people conceived through IVF appeared to be more susceptible to developing a metabolic pathology called insulin resistance.
According to the study's conclusions, it is also presumed that differences in cholesterol levels, glucose levels and other metabolic parameters could appear later in life.
The findings were published in the journal Circulation by David Celermajer, professor of cardiology at the University of Sydney Medical School.
However, he himself wanted to qualify and contextualize his findings.
"When all variables are considered, IVF parents should not worry. I think, to put it in perspective, IVF has given them, overall, very healthy children. And if this study is confirmed, it could imply that, once they grow up, they may have heart disease somewhat prematurely, in their 50s or 60s instead of 70s or 80s. So, if you compare that to the gift of life first, I don't think parents should be too worried right now.
The study was "relatively small," he said, and did not conclusively show that people born through IVF had more heart attacks or strokes.
"It just points to an area of potential concern rather than immediate concern."
Celermajer emphasized that the benefits outweigh the potential risks, but added that the recent research results provide a "somewhat worrying sign that manipulating nature in this way may have some adverse results."
Today, all the objectives in fertility research are set on minimizing them.
Main causes of potential alterations in children born through assisted reproduction
During IVF, doctors remove an egg from the ovaries and then incubate it together with the sperm in a test tube. Alternatively, they can inject a sperm directly into the egg to help with fertilization. The embryo created by this process is grown in culture for a few days and then implanted in the mother's uterus.
This phase of development is incredibly critical.
In those first 10 days after the egg and sperm meet to form an embryo, so much happens to determine the future health that even subtle changes in the physical and chemical environment can cause very important changes in the development of the baby in the end. of the gestation Dr. Michael Miller, a cardiologist at the University of Maryland Medical Center, agrees that lThe reason for high blood pressure is likely due to how genes are expressed during the “stressful and unnatural” conditions that can occur with IVF.
There are two possible causes of cellular stress that embryos can experience.
One, the physical stress of being picked up, injected, or handled, and the other, the chemical stress related to chemicals in the test tube environment or changes in oxygen level.
Sometimes cells that thrive in an environment where it is slightly more acidic, for example, can experience greater oxidative stress. And, in simple terms, this adversely affects cells' use of energy, growth and development.
Faced with this evidence that certain alterations could be a consequence of the chemical processes that occur while the embryo is still in the Petri dish, some scientists develop some fears.
It is believed that the chemical substances of the crops could influence the expression of some genes and this cause subsequent alterations. The fact that these alterations occur at such an initiation moment in the life of a being is especially worrying.
Being a stress experienced by the stem cells that we call pluripotent in the embryonic phase, it could end up affecting not only the blood vessels, but also other organs.
Little by little, studies on kidney, liver, lung, brain, or other organ conditions that have not been thoroughly studied right now will grow.
However, members of the Swiss team also pointed out that many people not born through IVF have these same genetic markers in advance and does not mean a significant decrease in their quantity or quality of life.
Many studies have been done on the psychosocial development of children born by IVF and on their likelihood of developing autism spectrum disorders, with or without hyperactivity. None of them have identified significant differences in this population group with respect to the general population.
Prevention and actions to avoid alterations in assisted reproduction
For now, studies say that assisted reproductive techniques potentially increase the probability of suffering from cardiovascular and metabolic disorders in adolescence. Faced with this potential situation, increasing healthy lifestyle habits is, without a doubt, the first of the recommendations to be made.
It is essential to maintain a diet that is mainly low in trans fats, from cooked vegetable oils, and low in poor-quality saturated fats, such as meat from large animals that have not been able to move with some freedom.
In addition, it is important that the diet is especially rich in vegetables, fruits, seeds, nuts, legumes, and good-quality protein, such as fish, shellfish, poultry, eggs, or grass-fed meat.
The excess of flour and sugar favors the appearance of metabolic syndromes that could end up negatively influencing cholesterol levels and cardiovascular pathologies. Quite the opposite of what would be recommended for the IVF Generation.
And studying the beneficial effects of intermittent fasting for this type of pathology would be equally recommended.
The last recommendation, but by no means least, would be to maintain a high level of daily movement. Minimum 30 minutes of light physical exercise a day, preferably outdoors and in the sun. If it were possible to combine light exercise with strength exercises, which help to increase muscle mass, it would be even more interesting in order to avoid metabolic pathologies. Muscle is a big consumer of blood sugar. The more muscle, the less risk of diabetes.
References:
- François Olivennes, P. Rufat, B. André, A. Pourade, MC Quiros, René Frydman, Pregnancy: The increased risk of complication observed in singleton pregnancies resulting from in-vitro fertilization (IVF) does not seem to be related to the IVF method itself, Human Reproduction, Volume 8, Issue 8, August 1993, Pages 1297–1300, https://doi.org/10.1093/oxfordjournals.humrep.a138245
- Bengt Källén, Orvar Finnström, Karl Gösta Nygren and Petra Otterblad Olausson. In vitro fertilization (IVF) in Sweden: Risk for congenital malformations after different IVF methods. Clinical and Molecular Teratology. Birth Defects Research Part A. First published: January 27, 2005 https://doi.org/10.1002/bdra.20107
- Konstantinidis G., Pavlović V., Stojadinović A., and Katić K. Characteristics and morbidity of prematurely born newborns conceived with assisted reproductive technologies. Srpski arhiv za celokupno lekarstvo 2020 Volume 148, Issue 9-10, Pages: 571-576. https://doi.org/10.2298/SARH191029049K
- Paul Merlob, Onit Sapir, Jaqueline Sulkes, Benjamin Fisch. The prevalence of major congenital malformations during two periods of time, 1986–1994 and 1995–2002 in newborns conceived by assisted reproduction technology. European Journal of Medical Genetics, Volume 48, Issue 1, 2005, Pages 5-11, ISSN 1769-7212, https://doi.org/10.1016/j.ejmg.2005.01.019.
- Michael von Wolff and Thomas Haaf. In Vitro Fertilization Technology and Child Health. Risks, Mechanisms and Possible Consequences. Dtsch Arztebl Int. 2020 Jan; 117(3): 23–30. Published online 2020 Jan 17. doi: 10.3238/arztebl.2020.0023
- Verdult R. (2021) The Psychotherapeutic Treatment of IVF/ICSI Babies: A Clinical Report. In: Evertz K., Janus L., Linder R. (eds) Handbook of Prenatal and Perinatal Psychology. Springer, Cham. https://doi.org/10.1007/978-3-030-41716-1_15
- Diop, H., Cabral, H., Gopal, D. et al. Early Autism Spectrum Disorders in Children Born to Fertile, Subfertile, and ART-Treated Women. Matern Child Health J 23, 1489–1499 (2019). https://doi.org/10.1007/s10995-019-02770-z
- Manon Ceelen, Mirjam M. van Weissenbruch, Jan PW Vermeiden, Flora E. van Leeuwen, Henriette A. Delemarre-van de Waal, Cardiometabolic Differences in Children Born After in Vitro Fertilization: Follow-Up Study, The Journal of Clinical Endocrinology & Metabolism, Volume 93, Issue 5, 1 May 2008, Pages 1682–1688, https://doi.org/10.1210/jc.2007-2432
- Cui, L., Zhou, W., Xi, B. et al.. Increased risk of metabolic dysfunction in children conceived by assisted reproductive technology. Diabetologia 63, 2150–2157 (2020). https://doi.org/10.1007/s00125-020-05241-1
- Christina Bergh & Ulla-Britt Wennerholm (2020) Long-term health of children conceived after assisted reproductive technology, Uppsala Journal of Medical Sciences, 125:2, 152-157, DOI: 10.1080/03009734.2020.1729904
- Taravat Talebi, Neda Mohsen-Pour, Mahshid Hesami, Majid Maleki & Samira Kalayinia (2021) The association between in vitro fertilization and intracytoplasmic sperm injection treatment and the risk of congenital heart defects, The Journal of Maternal-Fetal & Neonatal Medicine, DOI: 10.1080/14767058.2021.1949705
- Derk Kuiper, Annemieke Hoek, Sacha la Bastide-van Gemert, Jorien Seggers, Douwe J Mulder, Maaike Haadsma, Maas Jan Heineman, Mijna Hadders-Algra, Cardiovascular health of 9-year-old IVF offspring: no association with ovarian hyperstimulation and the in vitro procedure. Human Reproduction, Volume 32, Issue 12, December 2017, Pages 2540–2548, https://doi.org/10.1093/humrep/dex323
- Frank van Balen Development of IVF Children, Developmental Review, Volume 18, Issue 1, 1998, Pages 30-46, ISSN 0273-2297, https://doi.org/10.1006/drev.1997.0446.