From the Guidelines
The initial management for a hemodynamically stable ectopic pregnancy should be medical treatment with methotrexate, specifically a single intravenous or intramuscular dose of 50 mg/m2, as it is a useful and effective treatment strategy for patients with unruptured ectopic pregnancy 1.
Key Considerations for Methotrexate Therapy
- Methotrexate is contraindicated in patients with alcoholism, immunodeficiency, peptic ulcer, or active disease of the lungs, liver, kidneys, or hematopoietic system, and relatively contraindicated in patients with an ectopic gestational sac larger than 3.5 cm or with embryonic cardiac motion observed on ultrasound 1.
- Treatment success rates are lower in patients who have a b-hCG level of 5,000 mIU/L or more 1.
- Patients should be closely monitored for signs of treatment failure, including increasing pain and/or signs of hemodynamic instability, and should receive prompt diagnostic studies, such as abdominal and pelvic ultrasonography, to establish or exclude the diagnosis of ruptured ectopic pregnancy 1.
Monitoring and Follow-up
- Follow-up care is essential, with patients requiring outpatient management and monitoring of beta-hCG levels to assess treatment response 1.
- Arranging outpatient follow-up for patients who receive methotrexate therapy in the ED for a confirmed or suspected ectopic pregnancy is a Level B recommendation 1.
Potential Complications
- Treatment failure, with rupture of the ectopic pregnancy, is one of the most serious complications of methotrexate therapy, occurring in more than 20% of patients in several cohort studies 1.
- Ruptured ectopic pregnancy must be considered in the differential diagnosis of patients who present to the ED with concerning symptoms or signs after methotrexate therapy 1.
From the Research
Initial Management of Hemodynamically Stable Ectopic Pregnancy
The initial management of a hemodynamically stable ectopic pregnancy (EP) involves medical treatment, specifically the use of methotrexate, as an alternative to surgical therapy.
- Methotrexate is a folic acid antagonist that can be used to treat ectopic pregnancy, with a success rate of above 90% achievable in certain cases 2.
- The most commonly used protocol consists of methotrexate 50 mg/m of actual body weight, with assessment of human chorionic gonadotropin (hCG) levels repeated on days 4 and 7 2.
- Contraindications for methotrexate treatment include hemodynamically unstable patients or those with elevated liver enzymes, low white blood count, or abnormal renal function 2.
Factors Influencing Success of Methotrexate Treatment
The success of methotrexate treatment for ectopic pregnancy depends on several factors, including:
- Beta-hCG levels: Lower levels of beta-hCG are associated with higher success rates of methotrexate treatment 3, 4.
- Size of the ectopic mass: Smaller masses are more likely to be successfully treated with methotrexate 3.
- Relative changes in serum beta-hCG: A decrease in beta-hCG levels after methotrexate treatment can predict a successful outcome, with a cut-off value of 0.15 (15%) considered indicative of a positive result 4.
Expectant Management
Expectant management may be considered in cases where methotrexate treatment is not successful or not indicated, although there is limited evidence to support this approach 5, 3.
- Close monitoring of the patient's condition and beta-hCG levels is necessary to determine the best course of action 6.
Case Reports and Studies
Several studies and case reports have demonstrated the effectiveness of methotrexate treatment for ectopic pregnancy, including cases with high beta-hCG levels 6.
- A study published in 2004 found that methotrexate treatment was successful in 62% of cases with ruptured ectopic pregnancy and hemodynamically stable patients, and 81% of cases with unruptured ectopic pregnancy 5.
- Another study published in 2017 found that methotrexate treatment had a 95% probability of success if the relative change in beta-hCG from the 1st to the 4th day of monitoring was within a certain interval 4.