Tubal Ectopic Pregnancy: Management

MANAGEMENT

Management may be either surgical or medical, depending on a variety of factors. Surgery may be minimal or extensive, depending on the gestational age of the pregnancy and other factors. Due to the inherent risks of each, medical therapy is preferred over surgery in appropriate patients.

Medical Management Methotrexateis the medical treat-ment usually used as an alternative to surgical therapy. Methotrexate is a folic acid antagonist that competi-tively inhibits the binding of dihydrofolic acid to dihydro-folate reductase, which in turn reduces the amount of active intracellular metabolite, folinic acid.

The best candidate for medical therapy is the woman who is asymptomatic, motivated, and who has resources to be compliant with follow-up. Relative and absolute contraindications for medical management are listed in Box 13.1.

Factors that can be assessed in predicting the success of medical therapy include initial β-hCG level, size of ec-topic pregnancy as determined by TVS, and presence or absence of fetal cardiac activity. The initial serum β-hCG level is the single best prognostic indicator of treatment success in women given single-dose methotrexate. An ini-tial serum value <5000 IU/L is associated with a success rate of 92%, whereas an initial concentration >15,000 IU/L has a success rates of 68%. Although there are few data concerning the effect of ectopic pregnancy size on success rates with methotrexate, many early trials used “large size” as an exclusion criterion. Success rates with single-dose methotrexate were 93% in cases with ectopic masses <3.5 cm. Cardiac activity and size greater than 3.5 cm are considered relative contraindications to medical manage-ment because these findings are associated with a lower success rate.

The most common side effects of methotrexate in-clude nausea, vomiting, diarrhea, gastric distress, dizziness, and stomatitis. Intramuscular methotrexate given as a single dose has been the most widely used medical treatment of ectopic pregnancy. Close monitoring is imperative. A serum β-hCG level is determined before administering methotrexate and is repeated on days 4 and 7 following injection. Levels may continue to rise until day 4. Compar-ison is then made between the day 4 and the day 7 serum values. If there is a decline by 15% or more, weekly serum β-hCG levels are measured until they are undetectable. Ifthe β-hCG level does not decline, the patient may require either surgery or a second dose of methotrexate if no con-traindications exist. If there is an adequate treatment re-sponse, hcG determinations are reduced to once a week. An additional dose of methotrexate may be given if β-hCG levels plateau or increase in 7 days. Surgical intervention may be required for patients who do not respond to med-ical therapy.

During the first few days following methotrexate administration, up to half of women experience abdom-inal pain that can be controlled with nonsteroidal anti-inflammatory drugs. This pain presumably results from tubal distention caused by tubal abortion or hematoma formation or both.

Surgical Management Women who are hemodynami-cally stable and in whom there is a small tubal diameter, no fetal cardiac activity, and serum β-hCG concentrations <5000 IU/L have similar outcomes with medical or surgi-cal management. Conservative surgical techniques have been developed that maximize preservation of the fallopian tube. If removal is done through the laparoscope, definitive diagnosis and treatment can be accomplished at the same operation with minimal morbidity, cost, and hospitaliza-tion. In a linear salpingostomy, the surgeon makes an in-cision on the fallopian tube over the site of implantation, removes the pregnancy, and allows the incision to heal by secondary intention. A segmental resection is the removal of a portion of the affected tube (Fig. 13.5). Salpingectomy is removal of the entire tube, a procedure reserved for those cases in which little or no normal tube remains.

When conservative surgery or nonsurgical treatment is used, the patient must be followed posttherapy with serial quantitative β-hCG levels to monitor regression of the pregnancy. Subsequent surgery or methotrexate ther-apy is needed if trophoblastic function persists as evi-denced by persistent or rising levels of hCG. Rh-negative mothers with ectopic pregnancy should receive Rh im-mune globulin to prevent Rh sensitization.