Controversies Surrounding Stem Cell Technology

There have been many debates surrounding stem cell research since it was developed. They are primarily driven by the methods concerning embryonic stem cell (ESC) research. It was only in the year 1998 that scientists from the University of Wisconsin-Madison extracted the first human ESCs that we're able to be maintained alive in lab conditions. The main critique of stem cell research was that it required the destruction of a human blastocyst which is a fertilized egg that was not given the chance to develop into a fully-grown human.

When does life begin?

This is a highly debatable issue in the realm of developmental biology. Many researchers claim that life begins at conception which is the moment when the egg is fertilized. It is often argued that the embryo deserves the same status as any other full-grown human being. hence, destroying it (by removing the blastocyst to extract stem cells) is similar to murder. Others have identified different points in gestational development that ascertain the beginning of life such as after the development of certain organs or after a certain gestational period. Although some would argue that there is also a probability that even in normal conditions a fertilized and even an implanted egg may not achieve full growth.


People have also taken issues with the creation of chimeras. A chimera is an organism that contains both human and animal cells/tissues. Often in stem cell research, experimental procedures are undertaken wherein human cells may be inserted into animals (like mice or rats) and allowed to develop to see the results when stem cells are implanted. However, objections arise due to the creation of an organism that is "part human".

The stem cell debate has reached the highest level of courts in many countries. Production of ESC lines is deemed illegal in countries such as Austria, Denmark, Germany, France, and Ireland, but permitted in Finland, Greece, Sweden, Netherlands, and the UK. In the USA, although it is not illegal to work with or create ESC lines the issue arises in the area of funding, and it is, in fact, illegal for federal funds to be utilized in the research of stem cell lines that were created after August 2001.

What moral status does a human embryo have?

Point 1: The embryo has full moral status from fertilization onwards

Arguments for  Arguments against
The process of development of a baby from a fertilized egg is a continuous process and pinpointing the exact time when personhood begins is considered arbitrary. Although an embryo does not presently have the characteristics of a living person, it will eventually become a person and should be provided the respect and dignity of a person.

A preimplantation embryo cannot have the psychological, emotional or physical properties that we confer to a living person. It, therefore, would not have any personal interests that need to be protected and can be used for the benefit of patients.

The embryo grown in vitro cannot develop into a child unless it is transferred to a uterus. It needs external assistance to develop. Even then, the probability that the embryos that were used for in vitro fertilization will develop into full-term successful births is low. This is why many researchers believe that something that could potentially become a person should not be treated as if it actually were a person

Point 2: There is a cut-off point at 14 days after fertilization

Some people would argue that a human embryo deserves special protection from around day 14 after fertilization because after the 14th day, the embryo can no longer split to form twins. Before this stage, the embryo could still be split to give two or more babies, or it might abort entirely
Before day 14, the embryo has not yet developed a central nervous system and therefore has no senses. By this logic organs from patients who have been declared brain dead and used for transplants can be considered similar to hundred-cell embryos that have no nervous system.
The fertilization process itself is not a singular ‘moment’. An embryo in its earliest stages cannot be clearly defined as an individual.

Reproductive cloning and therapeutic cloning

There's is a clear difference between using cloning for reproductive purposes compared to therapeutic purposes.  It has a high failure rate, the benefits are unclear, and the consequences, known and unknown, provide a reason for hesitation in the scientific community. This is why most scientists are highly opposed to reproductive cloning and the creation of human beings and other animals using this technology.

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