Facts and Conclusion
Facts and Conclusion
Before we describe what three-parent in vitro fertilization is, let us first define what in vitro fertilization (I.V.F) is in the first place. In vitro fertilization is a process wherein the man’s sperm and a woman’s egg are fertilized outside the woman’s body (Storck, 2014). Once fertilization occurs and the fertilized egg divides to become an embryo, the embryo is placed in the uterus (womb) of the woman. Pregnancy in this sense happens once the embryo attaches to the lining of the uterus (Storck, 2014).
The process of in vitro fertilization is often done for couples who have difficulty conceiving a child due to different infertility problems. These infertility problems include older age of the woman, damaged or blocked fallopian tubes, endometriosis which means the cells from uterus grows in other parts of your body (Storck, 2013), and male factor infertility. According to the Society of Assisted Reproductive Technologies (SART), the success rate of I.V.F. up to conception of a live baby varies depending on the age of the woman. Generally, SART says for women under the age of 35, success rate is at 41 to 43 percent. For women who are 35 to 37 years old, the success rate is at 33 to 36 percent. For women aged 38 to 40, the success rate is at 23 to 27 percent while the success rate of women who are older than 40 is at 13 to 18 percent (as cited in Storck, 2014).
Scientists are now trying to refine the process to answer not only to infertility issues but prevention of some diseases that are inherited through the DNA present in mitochondria.
Mitochondria are called the ‘engines’ of a cell because they are responsible for driving metabolism through the key energy currency called adenosine triphosphate or ATP. As already mentioned, Mitochondria contains their own DNA which is called mitochondrial DNA (mtDNA). Typically these mtDNA are passed on solely from the mother to the offspring because the paternal mtDNA does not survive during fertilization and are destroyed. Mitochondrial DNA is passed to both female and male offspring and with it, any mutation or defect in the maternal mtDNA is also passed. The diseases that may arise therefore are manifested in the offspring regardless of the gender (Virginia Tech, 2008).
Two of the diseases that are caused by mutation in the mitochondria are Mitochondrial Encephalomyopathy with Lactic Acidosis and Stroke-like episodes (MELAS) and Leber hereditary optic neuropathy (LHON). Both diseases are inherited via the ovum which means that it is inherited through the maternal genes.
MELAS is a disease wherein, as suggested by the name, patients experience repeated stroke-like events. The disease, however, is different from the typical stroke because the part of the brain that is affected is different. Some of the symptoms accompanying the stroke-like event in MELAS are also different. For example, young patients without prior history of stroke or had never exhibited risk factor for it, sometimes experience stroke-like symptoms. These are usually followed by migraines, seizures, limb weakness and loss of hearing (Mandava, 2011).
LHON, on the other hand, deals with vision loss that usually begins in the teenage years or the twenties. The first symptoms of LHON are blurring and clouding of vision starting in one eye or in both eyes. These symptoms will only worsen over time until the patient can no longer detect sharpness or color in an image. In most cases, the effects of LHON are permanent (“Leber hereditary optic neuropathy,” 2013).
There are two methods of incorporating the mitochondria into the embryo. The first method is called Pronuclear Transfer, which means that the procedure is performed after fertilization. First, there needs to be two fertilized eggs – one from the parents and one from the donor. Both eggs should be fertilized by the same man. After that, the nuclear materials are removed from both the parents’ egg and the donor’s egg. The nuclear materials from the donor’s egg and the egg cell of the parents are discarded. The last step would be to insert the nuclear materials from the parents’ egg to the donor egg. The second method is called Maternal Spindle Transfer and is done before fertilization. The nucleus from the donor’s egg is removed and is replaced by the nucleus of the mother’s egg. The egg is then fertilized (Sample, 2013).
In my opinion TPIVF should be considered as a treatment. After all, several studies and researches have proved that it is safe and beneficial. As mentioned above, there are many diseases borne out of mitochondrial defects and if it could be prevented by TPIVF then why should we rob the future generation of such promise? The tipping point in the favor of TPIVF in my opinion is the living testimonies that TPIVF can change people’s lives and bring hope to otherwise devastated couples. Lives like Alana Saarinen (Weintraub, 2013) and Emma Ott (Tingley, 2014), who were both born through TPIVF, should be celebrated because they are the proof that medicine and science have upheld their core value – to help people.
Works Cited
(2013). Leber hereditary optic neuropathy. Retrieved from
http://ghr.nlm.nih.gov/condition/leber-hereditary-optic-neuropathy
Amato P., Tachibana M., Sparman M., & Mitalipov S. (2014). Three-parent in vitro fertilization:
gene replacement for the prevention of inherited mitochondrial diseases [Abstract].
American Society for Reproductive Medicine, 101(1), 31-35. Retrieved from
http://www.ncbi.nlm.nih.gov/pubmed/24382342
Madava, P. (2011). MELAS - Mitochondrial Encephalomyopathy, Lactic Acidosis, Strokelike
Episodes Overview of MELAS. Retrieved from
http://emedicine.medscape.com/article/1162238-overview#aw2aab6b4
Sample, I. (2013, June 28). Three-person IVF: UK government backs mitochondrial transfer.
TheGuardian. Retrieved from http://www.theguardian.com/science/2013/jun/28/uk-government-ivf-dna-three-people
Storck, S. (2013). Endometriosis. Retrieved from
http://www.nlm.nih.gov/medlineplus/ency/article/000915.htm
Storck, S. (2014). In vitro fertilization (IVF). Retrieved from
http://www.nlm.nih.gov/medlineplus/ency/article/007279.htm
Tingley, K. (2014, June 27). The Brave New World of ThreeParent I.V.F. The New York
Times. Retrieved from http://www.nytimes.com/2014/06/29/magazine/the-brave-new-world-of-three-parent-ivf.html?_r=0
Virginia Tech. (2008, January 31). How Mitochondrial Disease Is Passed Down From Mother To
Child: Predicting Severity. ScienceDaily. Retrieved October 29, 2014 from
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Weintraub, K. (2013, December 16). Three Biological Parents and a Baby. The New York Times.
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