August 2023

The Three-Parent In Vitro Baby

Three-parent in vitro fertilization (IVF) is a reproductive procedure aimed at preventing the transmission of certain genetic disorders caused by mitochondrial DNA mutations from mother to child. It is also known as mitochondrial replacement therapy (MRT) or mitochondrial donation, and the first baby born this way was in the US in 2016. 


This technique involves combining genetic material from three people – two biological parents and a female egg donor – to create a healthy embryo with minimized risk of mitochondrial-related diseases.


Mitochondria are tiny structures within cells responsible for producing energy. They have their own small amount of DNA, different from the nuclear DNA found in the cell's nucleus. Mutations in mitochondrial DNA can lead to serious health conditions, often affecting vital organs such as the heart, brain, and muscles. The severity of these conditions can vary widely, but they can potentially cause significant disability or even death in affected individuals.


The three-parent IVF technique was developed to address this issue. The procedure involves two main steps:

  1. Nuclear DNA Transfer: This step begins with the retrieval of eggs from the future mother and a healthy egg donor. The nucleus, containing the majority of the donor’s genetic material, is removed from the egg of the healthy person and replaced with the nucleus from the mother's egg. This process creates an egg containing the mother's nuclear DNA and the egg donor's healthy mitochondrial DNA.
  2. In Vitro Fertilization: The modified egg, now containing the nuclear DNA of the mother and the healthy mitochondria of the egg donor, is fertilized with sperm from the father using the IVF technique. This IVF embryo is then transferred to the mother's uterus for pregnancy.


The Three-Parent


By utilizing mitochondrial replacement therapy, the goal is to prevent the transmission of mitochondrial diseases from the mother to her child. The child's genetic makeup will consist of nuclear DNA from both parents, which determines traits and characteristics, and healthy mitochondrial DNA from the egg donor, ensuring the absence of mitochondrial mutations that cause diseases.


The three-parent IVF technique has sparked significant ethical and scientific discussions. Its critics voice concerns about the potential long-term effects of changing human genetics, as well as eventually unforeseen consequences. Additionally, the introduction of a third party's genetic material raises ethical considerations about the definition of parental identity and the potential for hereditary complexities.


Regulatory agencies and governments in various countries have taken different approaches to this technique. Some nations have chosen to allow the procedure under specific circumstances, such as the UK, while others, like the US, have prohibited it due to ongoing debates surrounding its safety, efficacy, and ethical implications.


In conclusion, the three-parent IVF technique, or mitochondrial replacement therapy, represents a pioneering approach in reproductive medicine designed to prevent transmitting mitochondrial diseases from mother to child. 


By combining nuclear DNA from the intended parents with healthy mitochondrial DNA from a donor, this technique has the potential to eliminate the risk of certain genetic disorders while sparking ongoing debates about its ethical and societal implications. As research continues, advancements in both technology and our understanding of genetics will shape the future of this revolutionary procedure.




  1. Schaefer GO, Labude MK. Genetic affinity and the right to 'three-parent IVF'. J Assist Reprod Genet. 2017 Dec;34(12):1577-1580. doi: 10.1007/s10815-017-1046-8. Epub 2017 Sep 18. PMID: 28920184; PMCID: PMC5714827.
  2. Rogers, K. (2014, December 3). Three-parent baby | Definition, Process, History, & Facts. Encyclopedia Britannica.