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Conception/Fertilization - What's The Difference?

What's the difference?

By Cecelia M. Cody

I was out having coffee with a pro-life friend a few weeks ago and we were discussing the question, "When does life begin?" She was making a definite distinction between "conception" and "fertilization," so I asked, "What's the difference?" My friend explained that when we are defending the sanctity of life, we usually use the word "conception" to mark the beginning of life. For example, we tell people that life is sacred from the moment of conception to the moment of natural death. However, she explained, due to some frightening happenings it may be time to be more precise with our language.

By "conception," we in the pro-life movement understand this word as meaning "the union of sperm and ovum." Another word for that same event is "fertilization." Even the U.S. Senate used these two terms synonymously as recently as 1982 in its two-volume report on the Human Life Bill then being debated. [1]

The meaning of the word "conception" has been intentionally changed by pro-abortion forces in recent years to refer not to the fertilization of the ovum by the sperm, but instead to the implantation of the blastocyst (the newly developing human at about a week after fertilization) into the wall of the mother's uterus. This change in definition has become so commonplace that it is reflected in standard medical reference books such as OB & GYN Terminology: "Conception is the implantation of the blastocyst. It is not synonymous with fertilization." [2]

One example of this change in definition is the following, a quote from Planned Parenthood's website:

"According to general medical definitions of pregnancy that have been endorsed by many organizations including the American College of Obstetricians and Gynecologists and the United States Department of Health and Human Services, pregnancy begins when a pre-embryo [3] completes implantation into the lining of the uterus. [4] Methods of contraception, including emergency contraception, prevent pregnancy by inhibiting ovulation, fertilization and/or implantation."[5]

So what's the big deal? Well, this means that now if a preborn baby is purposely killed before implantation, what happens is not called abortion (the name it deserves), but rather contraception, or the "prevention of conception." Look at that Planned Parenthood quote again - they are admitting that some methods of contraception prevent "pregnancy" by preventing "implantation"! If a baby is alive and ready to implant it her mother's womb, isn't the mother pregnant? (Yes!) Wouldn't killing this baby be abortion? (Yes!) Well, not any more! This shift in language is a public relations move to cover up countless abortions. Beware of these new definitions of words when you hear someone talk about "preventing conception." What they really mean includes ABORTION.

So, should we use the term "fertilization" now instead of "conception," just to be crystal clear in what we mean? With modern technology, genetic manipulation, and the threat of cloning, there can even be problems with saying "fertilization." Yes, human life begins with the union of sperm and ovum. But now, even though the procedures used are immoral and contrary to God's plan for creating people, some human lives may begin by other methods of asexual reproduction and the transfer of cell nuclei. Similarly, if a person were ever cloned, he or she would still be a person, with full human rights and dignity. Using the word "fertilization" might be seen as excluding these instances of human life.

So now, to avoid any confusion about whether or not the smallest human beings are persons, it may be best to explain that "human life is sacred, and is to be protected, from the single-cell stage." This wording makes it clear that implantation is not the start of a human life, and that all human beings are members of our family regardless of the circumstances of their beginnings.

[1] See Human Life Bill, US Senate Committee on the Judiciary, Subcommittee of Separation of Powers, 97th Congress, S-158, April-June 1982, Serial No. J-97-16).
[2] OB & GYN Terminology, E. Hughes, ed., Philadelphia: F.A. Davis, 1972.
[3] Note: There is no such official term as a "pre-embryo." Use of this term is yet another attempt to de-personalize the preborn human being.
[4] ACOG, 1998; DHHS, 1978; Hughes, 1972; "Make the Distinction..." 2001.
[5] From website dated August 2002,