Question: I need a diagnosis code for positive human chronic gonadotropin (HCG) four weeks after an abortion. The ultrasound showed no gestational sac. California Subscriber Answer: You can try reporting Z32.00 (Encounter for pregnancy test, result unknown). You shouldn’t use any diagnoses from the O04.- (Complications following (induced) termination of pregnancy) code category, because this is not a complication of the abortion. An elevated HCG along with no gestational sac may be an indication of ectopic pregnancy. Question whether this is something the ob-gyn suspects. If so, you’ve got another reason to report Z32.00 when the ob-gyn hasn’t confirmed the pregnancy or ruled it out at the time of performing the ultrasound.