An ectopic pregnancy happens when a fertilized egg implants outside the uterus. In most cases, it implants in a fallopian tube. This is a tube that goes from the uterus to an ovary. When this happens, the embryo can't grow normally. An ectopic pregnancy never becomes a normal pregnancy and birth.

In some cases, the embryo may stop growing quickly. Or it may grow until the fallopian tube tears (ruptures). This can cause severe bleeding, pain, and a risk of death.

Methotrexate is a medicine that stops the embryo from growing. The tissue is then absorbed by your body. This treatment can prevent the rupture, bleeding, and risk of death. Methotrexate is often used instead of surgery to remove the embryo. Surgery has risks, such as bleeding, infection, scarring of the fallopian tube, infertility, and the risks of anesthesia.

Methotrexate is most often given by a shot (injection) into a muscle. It can also be given through an I.V. (intravenous) line.

After having the shot, you may have:

• Mild belly (abdominal) pain or cramping.
• Nausea and vomiting.
• Diarrhea.
• Extreme tiredness (fatigue).

Once you are home, you can resume normal activities as you are able. You will have some bleeding and pain. While you are recovering, you can use acetaminophen for pain if advised by your doctor. You may be told to flush the toilet twice after each use to clear the toilet of methotrexate. Follow your doctor's specific instructions.

Do NOT do the following until your doctor says it's okay to do so:

• Do not take nonsteroidal anti-inflammatory drugs (NSAIDs), such as aspirin, ibuprofen, or naproxen.
• Do not have foods or vitamins that contain folic acid or folate (for example, prenatal vitamins have folate).
• Do not drink alcohol.
• Do not take penicillin or certain other antibiotics.
• Do not use tampons or douche.
• Do not have sex.

Make sure to:

• Stay out of the sun during the first week after your shot. This medicine can make your skin more sensitive to the sun and cause a rash during this time.
• Use birth control for at least 3 months after treatment.
• Talk with a counselor if you feel sadness or grief after pregnancy loss.

You will have blood tests several times in the weeks after you have the shot. This is to make sure that your pregnancy hormone (HCG) level is getting lower. This shows that the embryo is no longer growing. It may take up to 4 weeks for your level to drop to 0. In most cases, only one shot is needed. If HCG levels are not low enough, your doctor may give you a second shot. In some cases, this treatment does not work and surgery is needed. Your doctor can tell you more about surgery for ectopic pregnancy.

Contact your doctor now or seek immediate medical care if:

• You have lower belly pain that gets worse or doesn't go away.
• You have heavy vaginal bleeding.
• You have nausea or vomiting that needs treatment.
• You have dizziness, weakness, or fainting.
• You have a fever of 100.4°F (38°C) or higher, or as advised by your doctor.