Does a doctor always do a d & c on u after a spontaneous abortion?

Depends: Most of the time residual contents from a spontaneous abortion are removed by the ob, a d&c. But each case is different. Your OB will decide. Trust him/her.

Nope: If you had an sab, you shouldn't need a D&C unless you have continued bleeding & pain from retained tissue (incomplete abortion). Often, a non-viable pregnancy (like a blighted ovum = anembryonic pregnancy) can pass spontaneously & not require surgery. Like any surgery, make sure you understand why it's required. Ultrasound can easily be used to see if any tissue is retained & it's less invasive.