In this TED video, medical imaging expert Alexander Tsiaras presents a fascinating animation of prenatal development, showing both external and internal features. The emphasis is on the earlier stages of pregnancy, when development is most rapid. It's hard to know where Tsiaras stands on abortion-- the language used in the video varies widely-- but it's a wonderful pro-life resource. (The meat of the video begins at 1:55.)
I apologize that the embedded video is cut off at the side; this is a Blogger problem that I can't fix. To view the video with better quality, go here.