Can natural miscarriage be avoided without dilation and curettage?

Patient's question:

Gender: Female
Age: 25
Menstruation has been ongoing for a long time. About 10 days ago, there was a significant amount of dead blood, and now it has reduced noticeably, but sometimes there are still blood clots.
pH test strips show positive, but ultrasound shows no pregnancy. The doctor diagnosed a miscarriage.
What raises suspicion is that I have had an intrauterine device (IUD) in place. About 10 days ago, a clump of dead blood came out along with the IUD.
Duration and persistence of the current condition: Since early this month until now.
Medical history: None
Current general condition: Bleeding has decreased, but occasional blood clots still appear.

Doctor's answer:

Hello, this situation may be caused by incomplete miscarriage. It's best to have an ultrasound examination first, and consider a D&C if necessary. For miscarriage, it is recommended to go to a regular hospital gynecology department. The diet should be light, avoid spicy and irritating foods, and drink more water.