Contraindications to methotrexate. In addition to strict medical contraindications to methotrexate, relative contraindications that indicate a higher risk of methotrexate failure include the presence of fetal cardiac activity, EP mass greater than 4 cm, and serum hCG above 5,000 mIU/mL.26 Because of the potential risk of tubal rupture during medical management, relative contraindications also include patient inability to follow up as an outpatient and patient refusal of blood transfusion.26 Patients with contraindications to methotrexate, hemodynamic instability, ultrasonographic or clinical evidence of EP rupture, or those electing for surgical management may be managed with laparoscopy.11 Discussion of surgical management of EP is beyond the scope of this article.
Follow the hCG level. In patients with a failing IUP or an EP treated with methotrexate or salpingostomy, the hCG level should always be followed until it is negative, usually by weekly measurements once the diagnosis is made. In some cases, the hCG level may plateau after an initial decline, alerting the clinician to failed treatment for a known EP or the need for recategorization of a failed IUP as an EP.
CASE Concluded
The patient’s second and third hCG measurements at 2-day intervals were 1,903 mIU/mL (14% rise) and 2,264 mIU/mL (16% rise). At that point, a repeat transvaginal ultrasonography showed no IUP, adnexal mass, or free fluid. The patient was counseled for outpatient endometrial aspiration, which was performed using manual vacuum aspiration. The serum hCG level on the morning of the procedure was 2,420 mIU/mL. On postprocedure day 1, the serum hCG level fell to 1,615 mIU/mL, a 33% decline. The patient was counseled that this decline in hCG indicated a failing IUP. The final pathologic analysis was returned 3 days later, showing no evidence of trophoblasts and chorionic villi. Regardless, the diagnosis of failing IUP remained given the rapid hCG decline; the tissue from the disrupted failing IUP was likely very scant or simply not drawn into the cannula. Serum hCG levels repeated at weekly intervals revealed ongoing decline, and after 4 weeks, the serum hCG was negative.
In summary
For women diagnosed with PUL, the primary goal is to distinguish an IUP from an EP to reduce the risk of EP rupture through expeditious diagnosis and treatment. In women for whom the pregnancy is desired, distinguishing a viable IUP from a nonviable IUP or an EP is the more specific goal to avoid intervention on a viable IUP (with methotrexate or endometrial aspiration). In women with abnormal hCG trends and indeterminate ultrasonography results (particularly with a serum hCG above the discriminatory zone), outpatient endometrial aspiration is a highly effective way to determine pregnancy location, which dictates further treatment. ●