A fetus isn’t really a human being.
“Fetus” is a Latin term meaning “little one”, used to describe a stage of development, just like “infant”
or “adult.” According to the law of biogenesis, a fetus conceived by human parents, and growing according to the instructions in its own human genetic code, is by definition human.
Human life is a continuum, beginning with the newly conceived zygote, moving through the stages of embryo and fetus on through to adult. Although a fetus doesn’t look like an adult yet, neither does a newborn baby. A human fetus is no less human simply because it is smaller and more delicate.
For that matter, neither is an embryo less human, though it looks quite strange to our eyes, even in comparison to a fetus. Still, it is our duty to recognize our common humanity at all stages of development.