If I say, "Let only darkness cover me, and the light about me be night," even the darkness is not dark to thee, the night is bright as the day; for darkness is as light with thee. For thou didst form my inward parts, thou didst knit me together in my mother's womb. - Psalms 139: 11-13
My wife and I just passed the 10-week mark as we expect our first child. That puts our baby is at the same stage as the "precious feet". I'm not making any political, sociological, or philosophical arguments against abortion today; I just have these words and images to offer. I cannot imagine allowing something with those precious feet to be destroyed.
According to the Wikipedia pro-life article, "[b]iologically speaking, the zygote created at fertilization possesses a unique genome of human DNA, and the biological manifestations of a living organism." This makes the zygote itself - before it is a fetus or even an embryo - uniquely human. Those cells cannot and will not ever become anything else; they are destined to share either in our human life or, if we choose, human death.
Lastly, the an even stronger visual argument is made by this photo. The child has been developing for 21 weeks and has spina bifida. An in-utero surgery was being performed to correct the defect, when Samuel reached out and grabbed hold of the surgeon's finger. I dare anyone to look at this picture and say that Samuel is not already a person.