ICD-10CM = O20.0 for threatened abortion
CPT= 99283
In this case, there is a patient with threatened abortion and the physician decides to manage and monitor the patient. The CPT code should be 99283 since the problem doesn't need urgent treatment(still in monitoring) and low to moderate severity.
If the question about ICD-10 then it should be O20.0 for threatened abortion since the abortion has not happened yet.