Final answer:
The principal diagnosis for the patient with spotting, fever, a recent miscarriage, and products of conception found during aspiration dilation and curettage, who is now septic, should be puerperal sepsis.
Step-by-step explanation:
The patient in the scenario is experiencing a medical condition known as puerperal sepsis, also referred to as puerperal infection or childbed fever. This condition is associated with childbirth and the postpartum period where the female reproductive system is returning to a non-pregnant state.
Considering that the patient had a miscarriage and was treated for it, followed by symptoms of spotting and fever, and then treated with aspiration dilation and curettage with found products of conception, it is indicative that the principal diagnosis for this patient should be puerperal sepsis. The patient being septic means that the infection has spread, which aligns with the diagnosis of puerperal sepsis following a miscarriage.