More from Why Pro-Life? Caring for the Unborn and Their Mothers by Randy Alcorn (bold emphasis mine)
Many supporters of the pro-choice (abortion) movement argue that a baby is part of his mom. This is untrue:
"A body part is defined by the common genetic code it shares with the rest of its body. Every cell of the mother's tonsils, appendix, heart, and lungs shares the same genetic code. The unborn child also has a genetic code, but it is distinctly different from his mother's. Every cell of his body is uniquely his, each different from every cell of his mother's body. Often his blood type is also different, and half the time his gender is different.
If the woman's body is the only one involved in a pregnancy, then consider the body parts she must have - two noses, four legs, two sets of fingerprints, two brains, two circulatory systems, and two skeletal systems. Half the time she must also have male genitals. If it's impossible for a woman to have male genitals, then the boy she is carrying cannot be part of her body.
A Chinese zygote implanted in a Swedish woman will always be Chinese, not Swedish, because his identity is based on his genetic code, not that of the body in which he resides.
A child may die and the mother live, or the mother may die and the child live, proving they are two separate individuals. "
He writes more on the inconsistencies we see in our society:
"At the Medical University of South Carolina, if a pregnant woman's urine test indicates cocaine use, she can be arrested for distributing drugs to a minor. Similarly, in Illinois a pregnant woman who takes an illegal drug can be prosecuted for 'delivering a controlled substance to a minor.' This is an explicit recognition that the unborn is a person with rights, deserving protection even from his mother.
However, that same woman who's prosecuted and jailed for endangering her child is free to abort that same child. In America today, it's illegal to harm your preborn child, but it's perfectly legal to kill him. "
"Being inside something isn't the same as being part of something. (A car isn't part of a garage because it's parked there.) Louise Brown, the first test-tube baby, was conceived when sperm and egg joined in a Petri dish. Did she become part of her mother's body when she was placed in her uterus? No more than she'd been part of the Petri dish when she lived there.
Human beings shouldn't be discriminated against because of their place of residence. There's nothing about birth that makes a baby essentially different than he was before birth. There's no magic that changes a child's nature when she moves twenty inches, from inside her mother to outside."