Designer Babies/Three-Parent Babies
Science & Technology › Biotechnology – Applications · Topic 11.31
A designer baby is a child whose genes have been selected or edited before birth to give chosen traits, while a three-parent baby is a child born using mitochondrial replacement therapy, in which healthy mitochondria from a donor woman replace faulty mitochondria in the mother's egg, so that the child carries DNA from three people, mainly from the two parents with a small amount, about 37 genes, from the donor. The techniques are maternal spindle transfer and pronuclear transfer. Their aim is to prevent serious mitochondrial disease, which passes only from the mother. The United Kingdom legalised mitochondrial donation in 2015, and in 2025 researchers in Newcastle reported the birth of eight children by this method.
5 min read · UPSC Prelims · Science & Technology · Biotechnology – Applications
At a Glance
- Aim Prevent mitochondrial disease
- Methods Spindle and pronuclear transfer
- DNA from Three people
- Inheritance Mitochondria from mother only
- UK law Legal since 2015
- Exam link UPSC Prelims, Science & Technology: Biotechnology – Applications
Where Does It Fit?
This is the last topic of the macro on applications of biotechnology. It joins embryo transfer, stem cells and gene editing in one of the most debated uses of reproductive biotechnology. Previous topic: India’s First Biomass-to-Ethanol Plant and Its Commercialization. Next topic: Types of Orbits (LEO, MEO, GEO, Polar, Sun-Synchronous).
How Is a Three-Parent Baby Made?
| Technique | How it works |
|---|---|
| Mitochondrial disease | Faulty mitochondrial DNA causes conditions that affect muscles, brain and heart. It passes only through the mother’s egg |
| Maternal spindle transfer | The nucleus, held in a spindle, is removed from the mother’s unfertilised egg and put into a donor egg whose own nucleus has been taken out. The egg is then fertilised with the father’s sperm |
| Pronuclear transfer | Eggs are fertilised first. The pronuclei, which hold the parents’ DNA, are moved from the mother’s embryo into a donor embryo with the donor’s own pronuclei removed |
| Genetic result | The child has nuclear DNA of both parents and mitochondrial DNA of the donor |
| Carry over | A small amount of faulty mitochondria may move along with the nucleus, so some babies may still have mild risk |
| Sex of embryo | Only female babies pass on mitochondria, so some programmes choose male embryos to avoid inheritance |
| Alternative | Preimplantation genetic testing can help some couples to select healthy embryos |
What Is the Law and What Are the Ethical Issues?
- United Kingdom: the Human Fertilisation and Embryology (Mitochondrial Donation) Regulations 2015 made it the first country to legalise the method, with licensing by the HFEA
- Newcastle results: in July 2025 the team reported eight babies born after mitochondrial donation, and said the method was promising but not free of risk
- Mexico, 2016: a baby was born through spindle transfer in Mexico by a United States doctor, as the method was not allowed in his home country
- Australia: passed Maeve’s Law in 2022 to allow mitochondrial donation under licence
- United States: the regulator is barred by law from reviewing applications for the technique
- Heritable change: the change passes on to the daughters of the child, which makes the method a form of germline modification
- Safety and welfare: long term follow up of children is needed
- Designer baby fears: critics fear that these methods will lead to choice of traits like height or intelligence, which is not possible now with current science
What Else Should You Remember?
- Mitochondria: organelles that make energy in cells, with their own small circular DNA of about 16,500 base pairs and 37 genes, inherited from the mother
- Share of donor DNA: the donor contributes less than one per cent of the child’s DNA
- Designer babies: usually refers to selecting embryos by preimplantation genetic testing or editing their genes. In 2018 He Jiankui of China announced babies born from edited embryos, and was later jailed, as in Gene Editing (CRISPR) and Gene Therapy
- Preimplantation genetic diagnosis: testing embryos for serious inherited disease before transfer, allowed in many countries, as in Embryo Transfer Technology
- India: the Assisted Reproductive Technology (Regulation) Act, 2021 and the guidelines of the Indian Council of Medical Research do not permit germline gene editing or creation of embryos for modification in clinical practice, and sex selection is prohibited
- PCPNDT Act: the Pre-Conception and Pre-Natal Diagnostic Techniques Act, 1994 prohibits sex determination and selection
- Oviedo Convention: Article 13 of the European convention allows changes to the human genome only for preventive, diagnostic or therapeutic reasons, and not to change the genome of descendants
- Slippery slope: a concern that acceptance of one use will lead to others
- Social justice: access would be limited to the wealthy, which could widen inequality
- Consent: future generations cannot consent to heritable changes
- Patient groups: families with mitochondrial disease strongly support the research, because there is no cure
- Link: the nature of germline editing is also discussed in UK’s Approval of Gene-Editing License Research
Why Does It Matter for the Exam?
- Methods: maternal spindle transfer and pronuclear transfer
- Biology: mitochondrial inheritance from mother
- Law: UK 2015, Australia 2022, India’s ART Act
- Current affairs link: Newcastle babies and gene editing debates
- Common errors: saying the child has three full sets of parental genes, or that the donor passes on nuclear traits
As an analytical point, mitochondrial donation offers a way to prevent a serious inherited illness, but because it creates heritable change it needs strict licensing, follow up and public debate. Enhancement for non-medical reasons should stay outside the permitted area.
Why Is This Topic Important?
- Biology Mitochondrial DNA
- Methods MST and PNT
- Ethics Heritable change
What Came Next?
The next macro covers space technology and the Indian Space Research Organisation. Next topic: Types of Orbits (LEO, MEO, GEO, Polar, Sun-Synchronous).
Key People and Terms
- Mitochondrial DNA Maternal energy organelle DNA
- MST Maternal spindle transfer
- PNT Pronuclear transfer
- Germline Passed to offspring
- PGT Preimplantation genetic testing
- HFEA UK regulator
Exam Corner
Points to Remember
- UK legalised mitochondrial donation in 2015.
- Mitochondrial DNA has 37 genes.
- Donor gives under 1 per cent of DNA.
- Edited babies announced in 2018 in China.
- Australia’s Maeve’s Law: 2022.
Do Not Confuse With
- Three-parent baby and designer baby Disease prevention technique versus selection or editing of traits
- MST and PNT Egg stage versus embryo stage
- Mitochondrial and nuclear DNA Mother only, 37 genes versus both parents
Memory Hook
Faulty mitochondria swapped out; spindle before the sperm, pronuclei after.
Mains Angle
Questions ask about the technique, law and ethics. These points help.
- Benefit Prevent disease
- Concern Heritable change
- Law Licence and limits
A Question You May Face
An original practice question, not a past paper question.
“What is a three-parent baby? Discuss the scientific basis, the ethical concerns and the legal position of such technologies in India.”
How to Answer
- Science Mitochondrial replacement.
- Benefit Disease prevention.
- Concern Germline, equity.
- Law ART Act, ICMR.
GS Relevance
Frequently Asked Questions
What is a three-parent baby?
A three-parent baby is a child born using mitochondrial replacement therapy, in which healthy mitochondria from a donor woman replace the faulty mitochondria of the mother's egg or embryo. The child has nuclear DNA from the two parents and a small amount of mitochondrial DNA, under one per cent of the total, from the donor.
Why is mitochondrial replacement done?
Mitochondrial replacement is done to prevent serious mitochondrial diseases, which are caused by faults in mitochondrial DNA inherited only from the mother. These diseases can damage the brain, muscles and heart and have no cure. Replacing the faulty mitochondria offers a mother a chance to have a genetically related, healthy child.
What is the difference between maternal spindle transfer and pronuclear transfer?
In maternal spindle transfer, the nuclear material is moved from the mother's unfertilised egg into a donor egg before fertilisation. In pronuclear transfer, both the mother's and donor's eggs are fertilised first and the pronuclei, which hold the parental DNA, are moved from the mother's embryo into the donor embryo.
Where is mitochondrial donation legal?
The United Kingdom legalised mitochondrial donation in 2015 under a licensing system run by the Human Fertilisation and Embryology Authority, and Australia passed Maeve's Law in 2022. In the United States it cannot be reviewed by the regulator, and in India clinical germline modification is not permitted under the Assisted Reproductive Technology Act and medical research guidelines.
What are designer babies?
Designer babies is a popular term for children whose genes have been selected or edited before birth to give chosen traits. Selection of healthy embryos for serious disease is already done in many countries, but editing for enhancement is widely opposed. The 2018 birth of edited babies in China was condemned as unsafe and unethical.
PYQ Practice — Statement Analysis
1 Mitochondrial DNA is inherited only from the mother.
Through the egg.
2 The United Kingdom was the first country to legalise mitochondrial donation.
In 2015.
3 In maternal spindle transfer, the nucleus of the mother's egg is moved into a donor egg.
Before fertilisation.
4 The donor in a three-parent baby contributes most of the child's DNA.
Under one per cent.
Past Mains Questions on This Topic
This topic comes under Biotechnology – Applications. UPSC Mains questions asked on the matching syllabus topic, year-wise with marks:
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