Life News is carrying an interesting debate about whether pro-lifers should use the word “conception” or “fertilization” to describe the beginning of human life.
On one side of the debate is my friend, Jack Willke, M.D., the president of Life Issues Institute. Jack is long considered the father of the modern-day pro-life movement.
Dr. Willke agrues that “There was a meeting of officials of the American College of Obstetrics and Gynecology, the U.S. Food and Drug Administration, some drug companies, and a prominent physician, Alan Guttmacher. They … officially, but very quietly (ruled) that henceforth the word “conception” would no longer mean union of sperm and egg, but rather would mean implantation one week later.”
He also points out, “The word ‘pregnancy’ was also a problem, so they changed its definition from beginning at fertilization to beginning at implantation.”
Almost no one was told about it then, nor do most doctors know about it now, but this semantic redefinition enabled the drug companies to call the birth control pill and the IUD “contraceptives.”
So, Dr. Wilke concludes, “I have always recommended that we do not use the word ‘conception’ because of the confusion that these pro-abortion authorities have created. When we use ‘fertilization’ … it is clear that they mean that defining point when a sperm enters the ovum.”
On the other side of the coin, Paul A. Byrne, M.D., a Clinical Professor of Pediatrics University of Toledo College of Medicine and the past-President of the Catholic Medical Association, argues that “Life on earth for every person begins with conception.”
He argues, “Fertilization is a biological term that can be applied to reproduction of beasts that can indicate a new individual beast.” 
He goes on to say, “Life for every person begins with creation by the Creator. The reference to creation is prior to time. Life is the substantial fact of the existence in time. Human time begins with Adam and Eve. The living person is visible. The soul is the life of the person. It cannot be seen because it is spiritual.”
Dr. Byrne correctly says, “Immediately after conception. Every person since Adam and Eve, including Jesus, has lived within the body of his/her mother.”
He asserts, “Those who claim that a person begins at fertilization are not using the correct term or referring to the correct process. Sperm and ovum have the activities of individual cells, but they cannot be a cause of liberty or a rational soul. Fertilization is a physiological activity in beasts and plants, but this is not enough to understand human creation and procreation.”
My Take?
I’m comfortable with both terms, and usually use them together. If I had to choose one over the other, I’d lean toward conception. Why? It’s the term used in the Bible (see #3 below).
For me, the key is that at conception/fertilization, the life of a unique person of inestimable value begins.
And, I suspect Drs. Willke and Byrne would agree with me on these principles:
1) Humans are created in the Image of God 
Genesis 1:27 – God created man in His own image, in the image of God He created him; male and female He created them. 
(See also: Acts 17:28-29)
2) Life begins Spiritually in the Mind of God
Psalm 139:16 – Your eyes have seen my unformed substance; and in Your book were all written the days that were ordained for me, when as yet there was not one of them.
Jeremiah 1:5 – Before I formed you in the womb I knew you, and before you were born I consecrated you; I have appointed you a prophet to the nations.
Galatians 1:15 – …God…set me apart even from my mother’s womb… 
(See also: Ephesians 1:3-4; Zechariah 12:1; Isaiah 49:1; Romans 9:10-12)
3) Life begins physically and genetically at conception
Numbers 5:28 – But if the woman has not defiled herself and is clean, she will then be free and conceive children.
Job 3:3 – “Let the day perish on which I was to be born, And the night which said, ‘A boy is conceived’.”
Matthew 1:20 – …behold, an angel of the Lord appeared to (Joseph) in a dream, saying, “Joseph, son of David, do not be afraid to take Mary as your wife; for the Child who has been conceived in her is of the Holy Spirit.”
(See also: Judges 13:2)
4) God is wonderfully at work from conception through birth
Psalm 139:13-15: For You formed my inward parts; You wove me in my mother’s womb. I will give thanks to You, for I am fearfully and wonderfully made; Wonderful are Your works, And my soul knows it very well. My frame was not hidden from You, When I was made in secret…
Isaiah 44:2 — “Thus says the Lord who made you, your help, who formed you from the womb:”
Isaiah 44:24 — “Thus says the Lord, your redeemer, who formed you from the womb: I am the Lord, who made all things, who alone stretched out the heavens; when I spread out the earth, who was with me?”
(See also: Eccl 11:5; Lk 1:41; Isa 44:2; 66:9;  Gen 4:1; Job 31:15; Psa 22:9-10; 100:3)
5) God alone is sovereign over life and death
Deuteronomy 32:39 – ‘See now that I, I am He, and there is no god besides Me; It is I who put to death and give life. I have wounded and it is I who heal, and there is no one who can deliver from My hand.
Job 33:4 — “For the spirit of God has made me, the breath of the almighty keeps me alive.”
(See also: Isaiah 64:8, I Corinthians 6:8)
5) God condemns murder and abortion
Genesis 9:6-7 – Whoever sheds man’s blood, by man his blood shall be shed, for in the image of God He made man. As for you, be fruitful and multiply; populate the earth abundantly and multiply in it.
Exodus 20:13 – You shall not murder.
6) God gives children as a blessing
Genesis 1:28 – God blessed them; and God said to them, “Be fruitful and multiply…”  
Psalm 127:3-5 – Behold, children are a gift of the LORD, the fruit of the womb is a reward… How blessed is the man whose quiver is full of them…
(See also: Genesis 9:1; Genesis 35:11; Psalm 128:3; Luke 18:16)