An ectopic pregnancy is when the fertilized egg attaches (implants) outside the uterus. Most ectopic pregnancies occur in the fallopian tube. Rarely do ectopic pregnancies occur on the ovary, intestine, pelvis, or cervix. An ectopic pregnancy does not have the ability to develop into a normal, healthy baby. Having an ectopic pregnancy can be a life-threatening experience. However, if the ectopic pregnancy is found early enough, it can be treated with a medicine. This medicine is called methotrexate. Methotrexate works by stopping the pregnancy from growing. It helps the body absorb the pregnancy tissue over a 2 to 6 week period (though most pregnancies will be absorbed by 3 weeks).
If methotrexate is successful, there is a good chance that the fallopian tube may be saved. Regardless of whether the fallopian tube is saved, a mother who has had an ectopic pregnancy is at a much higher risk of having another ectopic occur in future pregnancies. One serious concern is the potential for the fallopian tube to tear (rupture). If it does, emergency surgery is needed to remove the pregnancy, and methotrexate cannot be used.
The ideal patient for methotrexate is a person who is:
Not bleeding internally.
Has no severe or persistent abdominal pain.
Is committed to following through with lab tests and appointments until the ectopic has absorbed.
Is healthy and has normal liver and kidney functions on evaluation.
Methotrexate should not be given to women who:
Have a normal pregnancy (intrauterine pregnancy).
Have liver, lung, or kidney disease.
Have blood problems.
Are allergic to methotrexate.
Have peptic ulcers.
Have an ectopic pregnancy larger than 1½ inches (3.5 cm) or one that has fetal heartbeats. This is a rule that is followed most of the time (relative contraindication).
Before giving the medicine:
Liver tests, kidney tests, and a complete blood test are performed.
Blood tests are performed to measure the pregnancy hormone levels and to determine the mother's blood type.
If the woman is Rh negative, and the father is Rh positive or his Rh type is not known, a RhoGAM shot is given.
There are 2 methods that your caregiver may use to prescribe methotrexate. One method involves a single dose or injection of the medicine. Another method involves a series of doses. This method involves several injections.
Blood tests will be taken for several weeks to check the pregnancy hormone levels. The blood tests are performed until there is no more pregnancy hormone detected in the blood. There is still a risk of the ectopic pregnancy rupturing while using the methotrexate. There are also side effects of methotrexate, which include:
Nausea and vomiting.
Increased abdominal pain.
Increased vaginal bleeding or spotting.
Hair loss. This is rare and reversible.
On very rare occasions, the medicine may affect your blood counts, liver, kidney, bone marrow, or hormone levels. If this happens, your caregiver will want to perform further evaluations.