This doctor writes, after observing her first second trimester procedure at 21 weeks:
Seeing an arm being pulled through the vaginal canal was shocking. One of the nurses in the room escorted me out when the colour left my face… Not only was it a visceral shock; this was something I had to think deeply about… Confronting a 21-week fetus is very different. It… cannot feel pain or think or have any sense of being, but the reality is, this cannot be called ‘tissue’. It was not something I could be comfortable with.
She decided to do only earlier abortions, in which the baby was either too young to have a human-looking appearance or so fragile that the suction machine would tear it into bloody, unrecognizable pieces.
The article was about the D&E procedure, which is what this abortionist witnessed. In this type of abortion, the baby is dismembered with forceps.
Source: “What about us? Staff reactions to D&E”. In: Hern WM, Corrigan B editor. Advances in Planned Parenthood. 15:1980;p. 3–8