Important: This is intended as general information only. It may not apply to your specific situation. It is not a substitute for medical advice. If you have a question or concern, please raise it with me at your next appointment or contact me sooner if it's urgent.
Ectopic Pregnancy
An ectopic pregnancy is a pregnancy that has implanted somewhere other than in the cavity of the uterus. Most of the time (about 95% of the time in fact), this means that it has implanted in the fallopian tube – a tubal ectopic. Less commonly, the pregnancy may implant on the ovary (ovarian ectopic), in the cervix (cervical ectopic), in the junction of the fallopian tube and the uterus (cornual ectopic) or somewhere else in the abdomen (abdominal ectopic). Since tubal ectopics are far and away the most common variety, I’ll talk about them for the bulk of this information page, with a few words about the other sorts at the end.
Unfortunately, the pregnancy cannot be ‘transplanted’ into the uterus and therefore to two cannot survive. Because the space within the fallopian tube is limited, eventually the growing ectopic can cause the tube to burst. This can result in extensive bleeding within the abdomen and, without appropriate treatment, it is possible to bleed to death from this condition.
Causes of tubal ectopics
Ectopic pregnancies occur at a rate of about one to two in 100 pregnancies. Sometimes this is just bad luck. Contrary to popular belief, most of the time the sperm fertilizes the egg in the fallopian tube, not in the uterus itself. If there are any factors present that slow the journey of the newly-formed embryo along the fallopian tube, the risk of an ectopic pregnancy occurring is increased. This includes anything that may have damaged the fallopian tube such as previous infection, endometriosis or previous surgery. Smoking is also associated with an increased risk of ectopic pregnancy.
Diagnosing tubal ectopics
We suspect an ectopic pregnancy in anyone who presents with pain in the lower left or right part of the abdomen, particularly if this is associated with light bleeding.
To make the diagnosis, we like to be able to see the ectopic pregnancy in the tube. Sometimes, particularly if the pregnancy is still very small, this is not possible – all we can see is that there is no pregnancy within the uterus. This is called an unsited pregnancy. Whenever we have an unsited pregnancy, there are three possibile diagnoses:
- Normal pregnancy too early to see yet
- Ectopic pregnancy
- Miscarriage
To work out the difference, we usually do serial blood tests measuring the level of bhCG (pregnancy hormone) in the patient’s circulation. In a normal pregnancy in the first trimester, we expect to see this level approximately double every 48 hours. If this is what happens, we wait until the level rises enough that we would expect to see the pregnancy within the uterus and then repeat the ultrasound scan. If the levels rises at less than this rate or stays stable, this is very suggestive of an ectopic pregnancy and we usually repeat the ultrasound after a few days. If the level falls, this suggests a miscarriage. In this situation, we follow the level to make sure it returns to zero.
Occasionally, a women will become unstable and display signs suggesting that she may be bleeding internally. Even if we have not firmly made the diagnosis at this stage, it may be appropriate to perform surgery. Usually, this involves performing a laparoscopy (key hole surgery inserting a camera into the umbilicus) to see what is going on. In severe cases, a laparotomy (an operation to open up the abdomen) may be necessary.
Treating tubal ectopics
Depending on the circumstances, there are a couple of options for treating tubal ectopics. Obviously, if there is any suggestion of heavy or life-threatening bleeding, immediate surgery is required. Fortunately, this is rarely necessary.
If the ectopic is small (as seen on ultrasound), the tube has not yet been damaged and the bhCG level is reasonably low, it may be possible to treat the ectopic with an injection of a drug called methotrexate. This drug kills the pregnancy tissue which is then gradually resorbed by the body. Providing we select the right ectopic to treat (in terms of size and hormone level), a single dose of methotrexate works in about 85% of cases. In the cases where it doesn’t work, a second dose of methotrexate or surgery may be required. In order to make sure that the treatment has worked, it is important to perform serial blood tests to make sure that the bhCG level returns to zero. Most people who receive this treatment have very little in the way of side effects. Side effects we sometime see include stomach upset and nausea.
If the ectopic is larger on ultrasound, or there are already signs that the tube may have been damaged, or the bhCG level is higher, surgery is necessary. In most cases, this involves surgery to remove the tube with the ectopic (called a salpingectomy). This can usually be done laparoscopically (with keyhole surgery) but a laparotomy (opening up your abdomen) may be required in some cases. Trying to open the tube, remove the ectopic and repair the tube (called a salpingostomy) generally doesn’t work all that well – it tends to leave you with a scarred tube that is more likely to get an ectopic in it in the future. For this reason we generally don’t perform a salpingostomy unless your other tube is already damaged or absent.
The main advantage of using methotrexate is that you avoid having surgery. There is also the potential advantage of retaining the affected fallopian tube. However, the tube is often blocked after the ectopic and methotrexate treatment and studies have shown that subsequent fertility rates are much the same with both surgery and methotrexate therapy.
Depending on your blood group, you may require an injection of anti-D – see the Blood Group and Pregnancy information page for more information about this.
After a tubal ectopic
You would think that losing a fallopian tube – either because it has been removed or is blocked following methotrexate – might make it difficult to get pregnancy again. In practice, however, this doesn’t seem to have as much of an effect as you would think, assuming that the other tube is normal. One normal tube seems to be all you need.
Some of the things that cause ectopic pregnancies (like previous infection and smoking) also reduce fertility in and of themselves. If there is damage to the other tube or some other underlying issue present, we may need to address this problem to help you get pregnant again.
Even if there was no obvious reason for the ectopic, we consider that you may be at increased risk of ectopics in the future. Therefore, it is suggested that anyone who has had an ectopic in the past should have an early ultrasound scan (about 6 weeks) in any future pregnancies.
After receiving treatment with methotrexate, it is recommended that you delay getting pregnant again for 3 months. It is also important to recommence your folate tablets (or pregnancy multivitamins) in preparation for a future pregnancy.
Other ectopic pregnancies
Ectopic pregnancies in other places (cornual ectopics, cervical ectopics, abdominal ectopics etc) are more complex. They can be harder to diagnose and more advanced at the time of diagnosis. Treatment is also more complex and needs to be individualized. We often use methotrexate but may need to inject it directly (guided by ultrasound or laparoscopy) into the pregnancy. Several doses of methotrexate or a combination of methotrexate and surgery may be necessary. If you find yourself in this situation, I will discuss it with you in detail along with all the options for treatment.