For example, the ob-gyn performs a dilation and curettage (D&C) for a blighted ovum (631, Other abnormal product of conception). In this case, the nonobstetrical D&C code (58120, Dilation and curettage, diagnostic and/or therapeutic [nonobstetrical]) doesn't seem right. The correct code, rather, depends on when - or if - the ob-gyn discovered the blighted ovum and pregnancy.
The treatment for a blighted ovum, which is a fertilized egg that fails to develop into a fetus, may be the same as a missed abortion, but only if the doctor has confirmed a pregnancy. For example, a patient may come in with unexplained vaginal bleeding before she realizes that she may have been pregnant, and a pregnancy test comes back negative. If this is the case, and there is a negative pregnancy test, you should report 58120 even if the pathology report indicates a blighted ovum after the fact.
On the other hand, if the ob-gyn has diagnosed the patient as pregnant either prior to or at the same visit and she begins to bleed, she may spontaneously abort, or she may require surgery to remove the retained products of conception. The blighted ovum may not become apparent until the pathology report comes back, but because there was a positive pregnancy test, you should report 59812 (Treatment of incomplete abortion, any trimester, completed surgically).
Although unusual, a patient with a blighted ovum may only complain of a missed period. The ob-gyn will likely order a pregnancy test and perform an ultrasound. If the pregnancy test is positive and the ultrasound reveals a blighted ovum (but no symptoms of abortion, for example, discharge or bleeding), the physician will likely perform a D&C. In this case, you would report 59820 or 59821 with 631. Submit the ultrasound with 76856 (Ultrasound, pelvic [nonobstetric], B-scan and/or real time with image documentation; complete).
With a blighted ovum, you are not inducing an abortion because there is no embryo or fetus. Rather, you may be helping along what nature has already started.