Controversies in family planning: persistently elevated serum human chorionic gonadotropin levels after aspiration abortion.

Low but rising serum human chorionic gonadotropin (hCG) levels occur infrequently after an induced abortion. Because this scenario rarely occurs after suction aspiration, clinicians may have higher suspicion for an uncommon diagnosis. The differential diagnosis includes both common and uncommon diagnoses, such as incomplete abortion, heterotopic or ectopic pregnancy, a new intrauterine pregnancy and gestational trophoblastic neoplasia. The etiology of this presentation may be unclear, especially in the absence of abnormal bleeding or pain which would suggest incomplete abortion, or when significant time has passed since the procedure. We describe two cases of an uncommon presentation of retained products of conception after aspiration abortion in which hCG levels were low but rising.