Pros and Cons of Stem Cells and Custom Babies

A close-up of genetic manipulation of a cell
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New discoveries continue to be made in genetic research and in vitro (IVF) techniques. The study of the human gene helps detect and one day may prevent diseases. In vitro allows for the manipulation of the mature eggs outside of the body which can then be fertilized and implanted back into the mother.

These technologies have led some to theorize that, in the near future, wanna-be parents will be able to create designer babies with the specific traits they desire.

Essentially, genetically modified (GM) humans.

Current Status of Stem Cell Manipulation

While the technology isn't yet available to design every aspect of your baby, the fact that people are talking about it means there are laboratories willing to make the effort to make it possible, no matter what the ethical costs.

In vitro does allow you to see the sex of an embryo before implantation. However, at this point in time, we only just beginning to understand how sex is determined in an embryo or the epigenetic controls that cause one gene to be preferentially expressed over another during blastocyst development. This kind of knowledge could then conceivably be applied to test-tube babies, but we are a long way off from that yet.


As we learn more about stem cells and the differentiation of pluripotent cells and epigenetics, the concept of controlling cell differentiation becomes more real. If we can control tissue formation and the size and shape of organs and the expression of genes controlling human traits, we can make designer babies.

The conclusion of the human genome project has also contributed to this fantasy of GM children since scientists have now sequenced each and every gene in the human cell and we are also well on our way to determining the function of each.


Parents can get what they want in at least the physical features of the child they conceive. Also, known, inheritable genetic diseases could be avoided.


To some, it just seems unethical to control what a child will be before they're even born. Maybe you want your child to be tall, or blonde, or athletic. There may be yet unknown consequences of manipulation.