Respect Life

When Does Life Begin?

The medical science community recognizes life begins at conception.

"Human development is a continuous process that begins when an ovum from a female is fertilized by a sperm from a male. Cell division, growth, and differentiation transform the fertilized ovum, a specialized cell called a zygote*, into a multi-cellular adult human being. Most developmental changes occur during the embryonic and fetal periods, but important changes also occur during the other periods of development: infancy, childhood, adolescence, and adulthood.
"Although it is customary to divide development into prenatal and postnatal periods, it is important to realize that birth is merely a dramatic event during development resulting in a change in environment.
"Development does not stop at birth."
The Developing Human: Clinically Oriented Embryology Fourth Edition, a medical school textbook on embryology by Dr. Keith L. Moore.

*Later in the same passage the term zygote is defined: "A zygote is the beginning of a new human being."

Other terms follow as defined in The Developing Human:
Embryo. This term refers to the developing human during the early stages of development.... The embryonic period extends until the end of the eighth week, by which time the beginnings of all major structures are present.
Fetus. After the embryonic period, the developing human is called a fetus. During the fetal period (ninth week until birth), many systems develop further. Though developmental changes are not so dramatic as those occurring during the embryonic period, they are very important.

Other quotes from the book, used to train obstetricians-to-be:
"In addition to caring for the mother, obstetricians must guard the health of the embryo and the fetus."
"Human development begins at fertilization, when a male gamete or sperm unites with a female gamete or ovum to form a single cell called a zygote (Gr. zygotos, yoked together). This cell marked the beginnings of each of us as a unique individual."