Kahono Hirasawa—McMaster Health Sciences 2026
You may have come across the term designer babies in recent years as the topic has started to rise in popularity. Although they may sound like babies who cruise around town in their Gucci baby stroller, snuggled up in their Louis Vuitton onesie, the reality is much more fascinating. Unfortunately, however, many still need to be made aware of the actual science, methods, and implications of the development of designer babies and how we may already be seeing the application of this technology all around us.
The idea of designer babies was initially proposed to reduce or avoid heritable diseases coded by mutations in our DNA, creating healthy and happier babies (1). This process is done by editing the genome through methods such as preimplantation genetic diagnosis or genetic modification (1).

SOURCE: inviTRA
Preimplantation genetic diagnosis (PGD) is the process of genetic testing of an embryo before it is implanted in the uterus and is used in conjunction with in vitro fertilization (IVF) (2). PGD identifies potential genetic abnormalities in embryos before embryo transfer (implanting a newly formed embryo into the woman’s uterus), commonly used to prevent single-gene conditions such as cystic fibrosis or sickle cell anemia (3). For example, in sickle cell anemia, a single allele point mutation can be targeted. However, more complex conditions such as autism involve the interaction of many genes and the environment and cannot be targeted or even understood as thoroughly. Despite this, PGD is available for all inherited conditions where the exact mutation is known and can be tested on the embryo (3).
The possibilities with PGD are still in development, and although the technique still suffers from limitations, it is a practical and more sensible approach to reducing heritable diseases.
However, the idea of the designer baby in popular culture has taken a new meaning and often refers to the use of genomic editing technologies for purposes beyond simply reducing heritable disease (1). Unlike PGD, the topic of gene editing in humans is an ever-changing debate on the ethics, morality, and beliefs regarding this technology’s political and social implications. Nevertheless, individuals have already begun creating babies with edited genomes and engineered mutations (4).
Individuals may take advantage of this technology to create babies with certain facial features and physical characteristics such as coloured eyes, athletic builds, and taller bodies. However, using genomic editing to create babies with “ideal” features strongly reinforces stereotypes and prejudice against people with features that are not considered a high priority for gene editing. Thus, the use of this technology poses various questions regarding its safety, ethics, and social implications. Furthermore, as this technology is in the early stages of development, it is likely that access to this resource will come at a high cost and will not benefit individuals who lack the necessary finances to support such procedures, widening the gap between the socioeconomic classes seen throughout society. A highly controversial use of genome editing is demonstrated when human genomes are altered using technologies such as CRISPR-Cas9 (6). CRISPR-Cas9 involves genome editing that may be used to make changes to genes in egg or sperm cells or to the genes of an embryo that could be passed to future generations. This application of genome editing raises the previously mentioned ethical concern of passing down enhanced human traits such as height or intelligence and the possible issues with the safety of such technique. In addition, it is possible that the use of CRISPR-Cas9 may produce “off-target” effects and can damage the genome in unpredictable ways.

SOURCE: The Scientist
Currently, genomic editing is conducted using genome editing tools to alter or destroy mutated mitochondrial DNA (1). In the embryo, thousands of copies of mitochondrial DNA (mtDNA) are present in the cell’s cytoplasm, which is highly prone to mutations (1). A high enough concentration of mutated mtDNA will lead to the development of mitochondrial diseases, which genomic editing hopes to reduce. This application of genome editing is widely accepted throughout the scientific community; however, it still comes with risks.
Thus, the creation of designer babies remains in the early stages of development. Although there have been many significant advances in genetic editing and modification in recent decades, the topic still causes many to question if it should even exist and the ethical controversies it proposes (5).
References
- Pang T.K. Ronald, Ho, P.C. Pang. Designer Babies [Internet]. 2016;26(2): 59-60. Obstetrics, Gynaecology & Reproductive Medicine. Available from: https://doi.org/10.1016/j.ogrm.2015.11.011
- Resnik Robert. Preimplantation Genetic Diagnosis: Molecular Genetic Technology. [Internet]. Creasy and Resnik’s Maternal-Fetal Medicine: Principles and Practice. 2019. Available from: https://www.sciencedirect.com/topics/medicine-and-dentistry/preimplantation-genetic-diagnosis
- UCSF Health. Pre-Implantation Genetic Diagnosis [Internet]. The Regents of The University of California. Available from: https://www.ucsfhealth.org/treatments/pre-implantation-genetic-diagnosis
- Cyranoski, David. The CRISPR-baby scandal: what’s next for human gene-editing [Internet]. Nature. 2019. Available from: https://www.nature.com/articles/d41586-019-00673-1
- Ly, Sarah. Ethic of Designer Babies [Internet]. The Embryo Project Encyclopedia; 2011. Available from: https://embryo.asu.edu/pages/ethics-designer-babies
- Medline Plus. What are genome editing and CRISPR-Cas9? [Internet]. National Library of Medicine. 2022. Available from: https://medlineplus.gov/genetics/understanding/genomicresearch/genomeediting/