Methotrexate for ectopic pregnancy

Methotrexate is typically given by injection. Two injection sites are sometimes used to administer one dose—this increases absorption of all of the medicine.

Methotrexate can be given by mouth. But ectopic pregnancy treatment success rates are lower with oral use than with injections.¹

Methotrexate stops the growth of rapidly dividing cells, such as embryonic, fetal, and early placenta cells.

During the week that you have methotrexate injections, your pregnancy hormone levels (human chorionic gonadotropin, or hCG) are tested several times. Your health professional will look for a drop in hCG levels, which is a sign that the pregnancy is ending (hCG levels sometimes rise during the first few days of treatment, then drop).

• If your hCG levels have dropped enough after 1 week, you are then tested on a weekly basis until they are low enough to suggest that the pregnancy has safely ended. This usually takes about a month but can take more than 3 months.
• If your hCG levels aren't dropping enough after 1 week, you will be given another dose of methotrexate. Your hCG levels will be monitored as above.
• If your hCG levels continue at higher levels, or if your health professional becomes concerned about tubal rupture, surgery will be needed to remove the ectopic growth.

Methotrexate can be used to:

• End an early ectopic pregnancy.
• Prevent the growth of any embryonic or fetal cells that are left behind after surgery to end an ectopic pregnancy.

It is also used to treat certain types of cancer, rheumatoid arthritis, and as part of an induced abortion.

Methotrexate treatment is most likely to be successful:

• When your pregnancy hormone (hCG) levels are low (less than 5,000).
• During the first 6 weeks of pregnancy.
• When the embryo has no heart activity.

Methotrexate treatment can be given as a single shot or as several injections. If an ectopic pregnancy continues after 2 or 3 doses of methotrexate, surgical treatment is needed to remove the ectopic pregnancy.

Methotrexate series. Although it is an uncommon practice, methotrexate can be given every other day until pregnancy hormone (hCG) blood tests confirm that the pregnancy has ended. On alternate days, a medicine called leucovorin (folinic acid) is given by injection to decrease methotrexate side effects. Treatment time for a methotrexate series varies from case to case but can take a month or longer.

Severe side effects from methotrexate treatment are usually related to longer-term use, such as for cancer treatment. Using alcohol or certain medicines during treatment can also lead to severe methotrexate side effects.

You will be advised to completely avoid the following until your treatment has finished:

• Vitamins containing folic acid, including prenatal vitamins
• Alcohol
• Penicillin

During treatment with methotrexate, only use a nonsteroidal anti-inflammatory drug (NSAID) for pain with your doctor's approval. NSAIDs can affect the level of methotrexate in the body. If you have nausea, do not use NSAIDs, which may make your nausea worse.

Common side effects of methotrexate treatment for ectopic pregnancy include:²

• Abdominal pain. Cramping abdominal pain is the most common side effect, and it usually occurs during the first 2 to 3 days of treatment. Because abdominal pain is also a sign of a ruptured ectopic pregnancy, report any abdominal pain to your health professional.
• Vaginal bleeding or spotting.
• Nausea, vomiting, and indigestion.
• Fatigue, lightheadedness, or dizziness.

Rare side effects from methotrexate treatment for ectopic pregnancy include:

• Skin sensitivity to sunlight.
• Inflammation of the membrane covering the eye.
• Sore mouth and throat.
• Temporary hair loss.
• Severe low blood counts (bone marrow suppression).
• Inflammation of the lung (pneumonitis).

Because of the risk of side effects, methotrexate treatment requires close medical supervision by a health professional who is experienced with this medicine. During methotrexate treatment, keep your health professional informed of any symptoms that you have.

See Drug Reference for a full list of side effects. (Drug Reference is not available in all systems.)

Methotrexate is sometimes used just after surgical treatment to stop the growth of any remaining fetal cells.

Methotrexate versus surgery

If your ectopic pregnancy is not too far advanced and has not ruptured, methotrexate may be a treatment option for you. Methotrexate treatment avoids the risks of surgery, may be less likely to damage the fallopian tube than surgery, and may offer a better chance of maintaining your fertility after treatment.

If you are not concerned with preserving fertility, surgery for an ectopic pregnancy is faster than methotrexate treatment and causes less bleeding.

Some women who receive a methotrexate series for ectopic pregnancy report more side effects and less overall comfort than women who have laparoscopy. On the other hand, women who have laparoscopy may experience side effects related to general anesthesia and surgery, such as fatigue, abdominal bloating, and shoulder pain.

Successful methotrexate treatment is less expensive than laparoscopic surgery for ectopic pregnancy.³

Methotrexate instead of surgery

Methotrexate can be used instead of surgery in the following cases:

• Pregnancy hormone (hCG) levels are low. Methotrexate treatment is not likely to be successful when hCG levels are high.
• No fetal heart movement is noted on ultrasound (methotrexate treatment is not as likely to be successful when the embryo is more developed and growing and has heart activity).
• The ectopic pregnancy is smaller than 4 cm.
• There is no bleeding into the abdomen.
• The fallopian tube has not ruptured.
• The use of anesthesia during surgery would pose a significant risk (for example, if you have a respiratory infection).
• You want to maximize your chances of becoming pregnant in the future.

When methotrexate cannot be used

Methotrexate cannot be used if you:

• Are breast-feeding.
• Have liver or kidney disease.
• Have a low red blood cell count (anemia).
• Have an impaired immune system.
• Have a ruptured fallopian tube.

If you are treated with methotrexate

You may be advised to avoid:

• Gas-producing foods, such as beans and cabbage, because abdominal discomfort is common with methotrexate.
• Exposure to the sun, because methotrexate can cause skin sensitivity to sunlight.
• Use of alcohol and other medicines.

Complete the new medication information form (PDF)(What is a PDF document?) to help you understand this medication.

Citations

1. Lipscomb GH, et al. (2002). Oral methotrexate for treatment of ectopic pregnancy. American Journal of Obstetrics and Gynecology, 186(6): 1192–1195.

2. American College of Obstetricians and Gynecologists (1998). Medical management of tubal pregnancy. ACOG Practice Bulletin No. 3. Obstetrics and Gynecology, 92(6): 1–7.

3. American Society of Reproductive Medicine (2006). Technical bulletin: Medical treatment of ectopic pregnancy. Fertility and Sterility, 86(4): S96–S102.