One disadvantage of methotrexate over surgery is the longer time period needed to resolve the condition, compared to the immediate surgical termination of the ectopic pregnancy. Side effects of methotrexate may occur (such as mild nausea), but they are generally not severe and are time limited.
For methotrexate treatment to be effective, the patient must fit several strict criteria. Below is a partial list of these criteria.
Usually, methotrexate is given as a single injection into a muscle. The dosage is based upon the patient's height and weight. A blood test for the hormone hCG is analyzed four days after the injection and is measured again seven days after the shot. The hCG level must decline at least 15% between the fourth and seventh day in order for the single injection to be considered successful. If the hormonal decline was not adequate, the patient is reassessed to determine whether a second methotrexate injection is appropriate. If the hormonal decline is adequate, weekly hCG levels are followed along with the woman's clinical status until it is determined that the ectopic pregnancy has been resolved. If the patient becomes unstable at any point in time, she is rushed to the hospital for surgical intervention.
Surgical therapy is generally chosen for women who are not candidates for medical treatment. These women may be in shock (hemodynamically unstable), have an advanced ectopic pregnancy (determined by high hCG blood levels or an ultrasound measurement of a large pregnancy sac), and be in moderate to severe pain.
"Conservative" surgery involves creating a small incision in the fallopian tube at the site of the tubal pregnancy. Depending on the individual circumstance, the surgeon may use laparoscopy (see above) or a larger, major abdominal incision to get to the fallopian tube. Once the incision into the tube is made, the ectopic pregnancy tissue is removed from the tube and the tube is allowed to heal naturally. This procedure preserves the fallopian tube. Occasionally, some of the pregnancy tissue is inadvertently left behind, necessitating the postoperative use of methotrexate or possibly another surgical procedure. If the tube heals well, it may function adequately in the future, allowing the patient to potentially conceive normally. However, if the tube heals poorly or was previously damaged, leaving it in place may make a future ectopic pregnancy more likely.
"Radical" surgery involves removing all or part of the fallopian tube via a procedure called salpingectomy. Again, performed by either laparoscopy or a larger abdominal incision, the potential advantage of removing the affected tube is a lower likelihood of accidentally leaving some of the ectopic pregnancy tissue behind (and therefore a lower probability of needing further treatment after the surgery). The disadvantage of removing the tube is the decrease in fertility that is generally experienced with an absent fallopian tube.