The Beginning and End of Life

Thirty-nine years ago the U.S. Supreme Court handed down the Roe v. Wade decision making abortion legal in this country. Rather than settle the matter, it sparked one of the most bitter and protracted political battles in our history. It might seem odd to be talking about court decision or political debates on a blog that deals with science, but much of the abortion debate hinges upon a fundamental scientific question. When does human life begin?

Philosophers and religious leaders have been arguing about this for millennia, but neither philosophical schema nor church scripture offered a definitive answer. Over time, scientists and physicians joined the debate. They applied the methods of science, developing techniques for examining and measuring fetal development with ever greater precision. But still, pinning down a specific point at which the fetus transforms itself from a collection of cells into an actual human being continued to elude them. Perhaps it’s time to turn the question around. Maybe the best way to find a definition of when life begins is to ask, “When does life end?”

At one time, death was pronounced when someone’s heart stopped beating, but as medicine advanced, and we learned to resuscitate hearts, the need for a new definition became apparent.  Nowadays, someone is declared legally dead, not when the heart stops but when his or her brain stops functioning.  That cessation of brain function has 3 primary components:

A)    The patient has an electroencephalograph (EEG) showing that there isn’t any brain activity, what’s commonly referred to as a flat line EEG

B)     The patient is unable to respond to stimuli like bright lights, loud noises or pain

C)      The patient is incapable of voluntary movement

If all three of those criteria are met doctors may legally declare the person dead.

The problem is that cells and tissues continue to live long after the brain has stopped functioning.  If they didn’t, organ transplants would be impossible.  The reason they’re possible is that organs such as the heart and kidneys, among others, continue to live, and if placed in a new body, have the potential to keep living.  Is it immoral to remove these tissues from a dead body and use them to save a life?

Most people would argue it isn’t. Even though the organs of the deceased are alive, even though each of the cells of the formerly living contain human DNA, we are willing to say that removing a kidney or a heart isn’t murder. We recognize that there is a difference between a patient and a cadaver. For legal and ethical purposes the difference is that a patient has a functioning brain with measurable brain waves and a corpse, zombie movies notwithstanding, doesn’t.


If death can be defined by the absence of brain activity, then we can use the same criteria, i.e. presence of brain waves, response to stimuli and voluntary movement, to determine when an embryo or fetus should be considered a human life.  Contrary to the claims of much of the anti-abortion literature and web sites, embryos do not have “brain waves” as early as 6 weeks from fertilization.  They may have some electrical impulses.  However, the term brain waves refers to specific types of electrical patterns produced by the region of the brain called the cerebrum.  This is the largest region of the brain. It gives us our higher brain function, our personality, our memories.  In short, it is the cerebrum that gives us the qualities that we consider human.  But this region doesn’t develop in the fetus until well into the second half of pregnancy.  The fetal brain isn’t developed enough to produce anything resembling brain waves until at least 20 weeks.

In 2008, census data showed the number of abortions performed in this country was 1,212,000, down from 1,313,000 in 2000. According to the Centers for Disease Control (CDC), typically 58% of abortions are performed before 8 weeks of pregnancy. 88% were performed before 13 weeks. At that stage of development the fetus has nothing resembling a brain capable of detectable brain waves. Put simply, if it were possible to perform an EEG on a fetus at this stage, it would be a flat line.

Then where do anti-abortion activists get the frequently cited idea that brain waves start at 6 weeks? Although sources are rarely given for this claim, an extensive search of their literature shows that it is based upon two sources. One is a speech presented at a 1964 American Medical Association (AMA) convention, subsequently printed in the Journal of the American Medical Association (JAMA). The second is a letter to the New England Journal of Medicine (NEJM) published in 1982. Neither the speech nor the letter was given any sort of peer review or cite any sources for their assertions. In the absence of that, they are simply unsubstantiated claims that should not be given any weight, no matter where they are printed.

Contrast that to a 2005 peer reviewed article in JAMA, Fetal Pain: A Systematic Multidisciplinary Review of the Evidence by Susan J. Lee, et al. The authors conducted an exhaustive search through the available scientific literature on pain perception in fetuses and concluded that it was highly unlikely that any fetus could perceive pain prior to the the third trimester.

Another article, Fetal Brain & Cognitive Developmentby Rhawn Joseph, Ph.D. published in 1999 in the journal Developmental Review states that a fetus doesn’t have a voluntarily response to stimuli until sometime between the

Normal fetus and fetus with anacephaly

20th and 25th week of

pregnancy. Similarly, a 2006 article in Seminars in Fetal & Neonatal Medicineby Dr. Ivica Kostovic, MD, Ph.D. and Dr. Natasa Jovanov-

Milosevic concluded that a fetus in incapable of voluntary

movement before this age. Any movements seen prior to this are the

result of involuntary reflexes and are seen in normal fetuses as well as those suffering from anacephaly, a condition in which the fetal brain never forms.

According to census data, very few abortions are performed after that 20 week point, to be precise, less than 1.4%. That means that 98.6% of all abortions are performed before the fetus has any measurable brain waves, before it is capable of voluntary movements, before it is able to respond to outside stimuli of any kind. If you were doctor with a patient who presented like that, you could reasonably declare the patient dead.

It is, therefore, not unreasonable to conclude that a fetus that meets these same criteria should probably not be considered alive. Aborting a 1st or 2nd trimester fetus is no more the destruction of a human life than performing an autopsy. That may seem unduly cold and clinical, but it’s important to remember that an abortion is a serious matter, considered long and hard by the woman undergoing the medical procedure, and the health-care providers performing it. To demean them or use anti-scientific hysteria to deny them the right to choose an abortion is to deny them the respect they deserve.