Ectopic Pregnancy: Why it Happens & What You Need to Know
An ectopic pregnancy occurs when a fertilized egg implants outside of the uterus—most often, in the fallopian tubes, but it’s also possible for an ectopic pregnancy to implant on the ovaries, in the abdomen, or in the cervix.
An ectopic pregnancy is a serious condition that can be life-threatening for the mother if left untreated. If you suspect that you may have an ectopic pregnancy, you should see a doctor right away.
Why do ectopic pregnancies occur?
In most pregnancies, the fertilized egg travels through the fallopian tubes to reach the uterus, where it implants in the uterine wall and begins to grow. But in about two percent of all pregnancies, the fertilized egg implants somewhere other than the uterus.
Most of the time, it is not possible to know exactly what caused an ectopic pregnancy. But there are some factors that can increase the risk of ectopic pregnancy, including:
- History of ectopic pregnancy. If you’ve had one in the past, you’re at increased risk to have another—though your odds of conceiving a healthy pregnancy are still much higher than your odds of another ectopic pregnancy.
- Infection of inflammation of the fallopian tubes, uterus, or ovaries. Anything that causes inflammation or infection in the reproductive system (pelvic inflammatory disease) can increase the risk of ectopic pregnancy. Often, the root cause is a sexually transmitted disease such as gonorrhea or chlamydia.
- Infertility and associated treatments. Some research suggests a connection between infertility and/or the use of fertility drugs and ectopic pregnancy.
- Structural issues. Ectopic pregnancies are more likely if you have an unusually shaped uterus, or if the fallopian tubes were damaged during surgery.
- Use of IUD. It’s very rare for pregnancy to occur when using an IUD. But if pregnancy does occur, it’s more likely to be ectopic. This is also true when pregnancy occurs after tubal ligation (AKA “having your tubes tied”).
- Smoking. Smoking cigarettes just before getting pregnant can increase the risk of ectopic pregnancy. The risk increases the more you smoke.
- Age. Ectopic pregnancy is more likely in women over the age of 35.
What are the signs of ectopic pregnancy?
Ectopic pregnancies may produce different symptoms in different women—especially early on, before the fertilized egg has grown large enough to cause any pain or other symptoms. At first, you may have typical early signs of pregnancy, such as breast soreness or nausea. You may also experience:
- Pregnancy spotting, or even bleeding that you might mistake for your period
- Lower back pain
- Mild cramping on one side of the abdomen
- Pain in the pelvic area
If the pregnancy continues long enough to cause a rupture, symptoms may intensify. These include:
- Fainting or dizziness
- Pressure in the rectum
- Low blood pressure
- Shoulder pain
- Sharp pain in the abdomen
How is an ectopic pregnancy diagnosed?
Most of the time, ectopic pregnancies are diagnosed using a combination of ultrasound and blood test. An ultrasound is used to show where a pregnancy is located. A pregnancy should be visible in the uterus by the sixth gestational week (since pregnancy is counted from the first day of the last menstrual period based on a 28-day cycle, six weeks pregnant is the same as two weeks after your missed period). An ectopic pregnancy is likely if there are no signs of an embryo in the uterus, but hCG levels are elevated and rising (as detected via blood test or home pregnancy test).
In addition to an ultrasound, two or more blood tests of hCG may be taken 48 hours apart (this is called a serial beta hCG test). In the early weeks of a normal pregnancy, hCG levels double roughly every 48 hours. Low hCG levels, or hCG levels that rise in an erratic pattern, suggest an ectopic pregnancy or miscarriage.
How is an ectopic pregnancy treated?
Once an ectopic pregnancy is diagnosed, treatment begins right away to avoid the risk of rupture. There are several different treatment options for ectopic pregnancy, including:
Ending the pregnancy with the medicine methotrexate. If the ectopic pregnancy was caught early enough (before a detectable heartbeat and/or when hCG levels are below 5,000), your doctor may recommend treating it with methotrexate. Methotrexate is most commonly used as a cancer drug. It works by stopping the growth of rapidly dividing cells. It is administered by injection.
After a methotrexate injection, your doctor will monitor your hCG levels to ensure they are falling. If the pregnancy continues after the first injection, you may need additional injections or surgical treatment.
After treatment with methotrexate, most physicians recommend taking between three and six months off from trying to conceive, as there is some concern that residual effects of the drug may contribute to birth defects[1.https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3024157/].
Ending the pregnancy with laparoscopic surgery. If your ectopic pregnancy is causing severe symptoms or has progressed beyond the early stages, surgery under general anesthesia may be required. Laparoscopic surgery uses a small incision to remove the pregnancy and repair the fallopian tubes.
Ending the pregnancy with emergency surgery. If the ectopic pregnancy has already ruptured, emergency surgery is required to remove part or all of the fallopian tube. One of the risks of surgery is further scar tissue that can make ectopic pregnancy more likely in the future.
Monitoring the pregnancy with expectant management. Some ectopic pregnancies miscarry on their own. If your pregnancy is early and appears to be ending by itself, your doctor may suggest no treatment while monitoring your hCG levels to ensure that they are dropping.
Is it possible to save an ectopic pregnancy?
Unfortunately it is not possible to save an ectopic pregnancy. Once a fertilized egg implants outside of the uterus, there is no way to transfer it to the uterus. If the pregnancy continues to progress without treatment, it will eventually burst the fallopian tube, ending the pregnancy and threatening the mother’s life.
Will an ectopic pregnancy impact my chances of getting pregnant again in the future?
The chances of having a successful pregnancy after an ectopic are very good. Sixty-five percent of women achieve healthy pregnancy within 18 months of their ectopic pregnancy, and some studies suggest this figure rises to around 85 percent after two years. These figures look at post-ectopic pregnancy outcomes as a whole—your individual chances of conceiving will depend very much on the health of your tubes, and what kind of treatment you had for your ectopic pregnancy.