Written by Ada’s Medical Knowledge Team
What is an ectopic pregnancy?
An ectopic pregnancy, also known as an extrauterine pregnancy, is a fairly common pregnancy complication, in which a fertilized egg implants and develops outside of the uterus, also known as the womb. The word ectopic means ‘out of place’. In about 95 percent of cases, the fertilized ovum, also known as an egg, implants in one of the fallopian tubes. This is often due to scarring from previous infection or other abnormalities in the pelvic area, but it can also happen without a clear cause.
The symptoms of an ectopic pregnancy include vaginal bleeding, abdominal pain and absence of menstruation. However, some people experience symptoms that are similar to those found in gastroenteritis, also known as stomach flu, and miscarriage. 1 Ectopic pregnancy may also be asymptomatic.
While most people make a good recovery from an ectopic pregnancy, the condition can be life -threatening if left untreated. An ectopic pregnancy cannot be moved to the uterus to grow normally and almost never survives until birth. It may pass out of the cervix on its own, though medical or surgical intervention is normally required. 2
Many people experience emotional distress after an ectopic pregnancy, particularly if it occurs during a planned pregnancy. A range of therapeutic treatment options are available.
Ectopic pregnancy symptoms
If symptoms of ectopic pregnancy occur, they typically appear early on in the pregnancy, sometimes before a person realizes they are pregnant.
- Lower stomach pain. Ectopic pregnancy pain is often located on one side of the body
- Vaginal bleeding, which may be dark, watery and heavier, lighter or more prolonged than a normal period
- Pregnancy symptoms such as a missed menstrual period, breast tenderness, frequent urination or nausea
However, it is possible to have an ectopic pregnancy without any of the above symptoms.
Other signs of ectopic pregnancy
Less common symptoms include:
- Bowel and bladder problems, such as diarrhea, and pain when defecating or urinating
- A feeling of fullness when lying down that is not associated with eating, particularly in people who have already had a child
- Back pain
It is possible to have an ectopic pregnancy without experiencing any symptoms until rupture of the fallopian tube or close organs. After rupture, signs and symptoms may include: 3
- Severe stomach pain
- Vaginal bleeding
- Lightheadedness, sometimes followed by fainting
- Shoulder pain, described as a strange pain that feels different to any pain that a person has otherwise experienced, located at the tip of the shoulder, where it joins the arm, caused by internal bleeding
What causes ectopic pregnancy?
When a person becomes pregnant, the sperm and the egg, also known as an ovum, join in the fallopian tube, the tube that carries the ovum from the ovary to the uterus. Usually, the fertilized egg passes along the fallopian tube and into the uterus and implants into the lining of the uterus, known as the endometrium, where it will grow and develop.
Ectopic pregnancy occurs when a fertilized egg implants and starts to grow outside the uterus, usually in a fallopian tube. This is often due to scarring from previous infections or other abnormalities in the tube’s shape, for instance a birth defect.
As the ectopic pregnancy gets bigger, it can run out of space to grow and rupture the fallopian tube, causing severe pain and internal bleeding. Rarely, an ectopic pregnancy can also occur in other places, such as the ovary or inside the abdomen.
Previous ectopic pregnancy: If a person has experienced an ectopic pregnancy already, they have an increased risk of having another one.
Fertility treatment: Embryo transfer during in vitro fertilization (IVF) can occasionally result in ectopic pregnancy if, for example, an embryo travels into the fallopian tube.
Infertility: Women with infertility have a two or three times higher risk of ectopic pregnancy, possibly reflecting the increased number of people in this group who have tubal abnormalities, which may also be a cause of infertility. 6
Age: The risk of ectopic pregnancy increases with age.
Pelvic inflammatory disease (PID): Previous infection of the pelvic region, commonly chlamydia and gonorrhea, can sometimes damage the fallopian tubes.
Tubal sterilization: People who become pregnant after tubal sterilization, either because it has failed or because they have had it reversed, are at higher risk.
Cesarean section: An embryo can implant in the scar tissue of the uterus lining, caused by cesarean section.
Copper contraceptive coil (IUD): IUDs ensure a very low risk of any pregnancy, either intrauterine or ectopic. However, if a person does conceive, the probability of the pregnancy being ectopic is higher than in women not using an IUD. 3 An IUD is still more protective against ectopic pregnancy than not using contraception.
Smoking tobacco: This can hinder the transfer of the ovum to the uterus by decreasing the ability of the muscles in the fallopian tube walls to contract.
In-utero diethylstilbestrol (DES) exposure: Exposure before birth to DES, a synthetic form of the female hormone estrogen that was prescribed to pregnant women from the 1940s to 1970s to prevent pregnancy complications, has been found to increase the risk of ectopic pregnancy by about four times. 6
Types of ectopic pregnancy
The kind of ectopic pregnancy a person has depends on where the fertilized egg implants.
Also known as tubal pregnancy, a fallopian ectopic pregnancy can be further divided into three sub-types:
- Ampullary (in the middle part of the fallopian tube), accounting for 80% of ectopic pregnancies
- Isthmic (in the upper part of the fallopian tube close to the uterus), accounting for 12% of ectopic pregnancies
- Fimbrial (at the end of the tube), accounting for 5% of ectopic pregnancies
The tube has a delicate structure made up of cilia, which are tiny hair-like projections, and mucus-producing cells, which work together to propel an ovum, fertilized in the fallopian tube, to the uterus to implant, over the space of about four days.
Sometimes, the transportation of the developing embryo is slow, perhaps for reasons of inflammation or infection of the fallopian tube or for no obvious reason. In such cases, it can implant in the fallopian tube.
About 95 percent of ectopic pregnancies occur in the fallopian tube.
Other types of ectopic pregnancy
There are other types of ectopic pregnancies, all of which are rare. These include: 7
Interstitial pregnancy: This occurs in the part of the fallopian tube embedded in the uterus wall. It is typically hard to diagnose and can therefore be particularly dangerous, as it may progress further and rupture later, damaging both the fallopian tube and the uterus wall.
Cervical ectopic pregnancy: Pregnancy in the cervix – the passage between the womb and vagina – is one of the rarest forms of ectopic pregnancy and carries a risk of life-threatening vaginal hemorrhage. This is due to the possibility of heavy bleeding when the ectopic pregnancy tissue separates from the cervix, which contains many blood vessels.
Ovarian ectopic pregnancy: This is typically difficult to diagnose, as it can appear very similar to a tubal ectopic pregnancy that is stuck to the ovary. It is usually not diagnosed until surgery, when partial or complete removal of the ovary will usually be necessary.
Cesarean scar ectopic pregnancies: This occurs when a fertilized egg implants into the scar from a cesarean section. The pregnancy can grow out of the uterus or into the cervix, which can lead to massive internal or vaginal bleeding. In some cases, the fetus may be able to survive until birth, but with the risk of significant maternal bleeding and removal of the womb, known as hysterectomy, at delivery.
Intramural pregnancy: This is a difficult-to-diagnose pregnancy that implants outside of the womb cavity, but within its muscular wall. It may occur if the uterus is scarred from surgery or if a condition called adenomyosis is present, in which the inner lining of the uterus breaks through the muscle wall of the uterus.
Abdominal pregnancy: Pregnancies in the abdomen are thought to start as tubal pregnancies, before separating from the wall of the fallopian tube and passing into the abdominal cavity, where they reattach. These can take many weeks before showing symptoms.
Heterotopic pregnancy: This term describes the co-existence of an intrauterine pregnancy and an ectopic pregnancy. The intrauterine twin is able to survive until birth in about one third of cases, after surgical treatment of the ectopic pregnancy.
Diagnosis of ectopic pregnancy usually begins with a physical exam and taking the person’s medical history. A person may be referred to a gynecology clinic for further assessment.
Ectopic pregnancies are most commonly diagnosed using a combination of tests, including:
- Human chorionic gonadotropin (hCG) test
- Laparoscopy (keyhole surgery) if the previous exam results are still ambiguous
Good to know: Diagnosis of ectopic pregnancy can be delayed because the symptoms are often similar to other, more well-known conditions, such as gastroenteritis, appendicitis or miscarriage. For more information, see the resource about signs of miscarriage.
Ultrasound is an imaging technique which uses soundwaves to create an image of the developing pregnancy. It is a painless and non-invasive procedure which can be performed in two different ways: 8
- Transvaginally: A scanning probe is inserted into the vagina.
- Transabdominally: Gel is spread onto the skin of the lower abdomen, and the scanner is passed over the area.
In diagnosing an ectopic pregnancy, doctors will look for where the pregnancy is located in the ultrasound images. These can help them determine whether the person’s symptoms are being caused by an ectopic pregnancy, a healthy pregnancy or another condition. Ultrasound indicators for ectopic pregnancy include: 9
No pregnancy in the uterus, or a gestation sac in the uterus missing an embryo: This is a pregnancy of unknown location (PUL). This is a label given until the pregnancy location can be found, and a diagnosis can be given. Many of these will not be ectopic and will not need treatment.
No pregnancy in the uterus and a possible mass in the area of a fallopian tube: This would likely lead to diagnosis of a possible ectopic pregnancy.
hCG test for ectopic pregnancy
Human chorionic gonadotropin (hCG) is a hormone produced by the placenta, an organ that develops in the womb during pregnancy. A beta hCG blood test can detect hCG in the blood approximately 11 days after conception and establish the precise amount of hCG present. This might be used if a person has been pregnant for six weeks, but an ultrasound scan does not show a developing pregnancy in the uterus. The test may be repeated at intervals to measure changes in hCG levels. 10
Possible indicators for ectopic pregnancy from a beta hCG blood test include: 11
- Declining hCG levels: This can be an indicator that the ectopic pregnancy has ended and is self-resolving or will be miscarried in the coming days or weeks.
- Slow rising hCG levels: If the levels rise more slowly than in a normal pregnancy, it is likely that the pregnancy is ectopic.
In a healthy pregnancy, hCG levels in the blood double about every two to four days throughout the first trimester, reaching their peak after 8-11 weeks and then decreasing before plateauing during the second trimester.
Rarely, laparoscopy, a type of keyhole surgery, is used to confirm the diagnosis, if hCG and ultrasound results are ambiguous. Under general anesthetic, a laparoscope, a narrow instrument with a camera and light on the end, is inserted through a small cut, usually into the belly button, to look at the pelvis. If an ectopic pregnancy is found, treatment to remove it may take place during the same operation. 3
An ectopic pregnancy can be life threatening if left untreated and normally requires medical or surgical intervention to remove it. However, in some cases, when it is diagnosed early, ectopic pregnancy may be monitored to see if it will resolve on its own.
Treatment options depend on:
- HCG levels
- How many weeks pregnant the affected person is
- Size and impact of the ectopic pregnancy as shown on an ultrasound
- Pain levels
- General health
- The options the hospital has available
- Personal views and preferences, such as future pregnancy plans
Also known as conservative or wait-and-see management, expectant management involves waiting to see if the ectopic pregnancy tissue passes out of the cervix on its own, instead of undergoing immediate treatment.
Expectant management is only offered as an option in some cases of very early diagnosis. Candidates for expectant management of ectopic pregnancy should: 12
- Be asymptomatic
- Show signs that the ectopic pregnancy is resolving, such as declining beta-human chorionic gonadotropin (β-HCG) levels
- Not show signs of rupture
- Not show signs of hemodynamic instability (abnormal blood pressure)
- Have easy access to a hospital and be prepared to continue with follow-up
- Be willing to accept the potential risks of tubal rupture
The approach involves close monitoring by medical professionals through repeated blood tests to check that hCG levels are dropping. It can take a few weeks or sometimes months for this to happen. About half of ectopic pregnancies may resolve on their own where there is a drop in hCG levels.
If a person develops new symptoms, another ultrasound scan may be done, and treatment options will be reassessed. Medical or surgical intervention may be required if it does not complete as planned.
Medical management with methotrexate for ectopic pregnancy
Sometimes, an ectopic pregnancy may be treated with a medication called methotrexate. This stops the growth of the embryo and typically allows surgery to be avoided. Medical management may be suitable if a diagnosis has been made very early.
Treatment with methotrexate is an especially attractive option if the pregnancy is located in the cervix or ovary or in the interstitial or the cornual portion of the tube. Surgical treatment in these cases is often associated with an increased risk of hemorrhage.
Methotrexate is administered as an injection, usually a single shot into the buttock muscle. After the injection, there may be an overnight stay in hospital, and regular follow-up visits will be needed for a few weeks to monitor hCG levels until they return to normal. Some people will need a second injection of methotrexate. Very occasionally, surgery will still be required.
Some pain is likely in the first few days after the injection, but this can usually be controlled with paracetamol. Certain substances should be avoided during treatment, including: 3
- Nonsteroidal antiinflammatory drugs (NSAIDs), e.g., ibuprofen or naprosyn, as they can interact with methotrexate and reduce its effectiveness
- Alcoholic beverages, as the liver will be working hard to metabolise methotrexate
- Supplements containing folic acid, as this can interact with methotrexate, preventing it from achieving the desired effect
Good to know: Apart from being used as a medication for ectopic pregnancy, methotrexate is a chemotherapy drug and immune system suppressant used to treat a variety of other conditions. It can cause significant side-effects. However, the dose to treat ectopic pregnancy is much lower and is unlikely to cause severe problems.
Ectopic pregnancy removal with surgery
There are two possible aims for surgical management, which will be decided depending on damage to the affected fallopian tube and the condition of the other tube. These are: 12
Total salpingectomy: This involves removal of the tube containing the ectopic pregnancy and is normally recommended for people who either do not want to have any children in future, who have had another ectopic pregnancy in the same fallopian tube, or who have severely damaged tubes. This reduces the risk of a persistent ectopic pregnancy, in which some ectopic cells are left behind and continue to grow, or further ectopic pregnancies. Total salpingectomy may also be chosen in cases of uncontrolled bleeding and abnormal blood pressure.
Linear salpingostomy: This is a more conservative approach, involving a surgical incision into a fallopian tube, which aims to remove the ectopic pregnancy without removing the tube. This is normally recommended for people who have an unruptured ectopic pregnancy in the ampullary (middle) portion of the tube. This may also be chosen if the person only has one tube, or their other tube does not seem to be healthy. It carries a higher risk of future ectopic pregnancy and persistent ectopic pregnancy, but still leaves the possibility of a future uterine pregnancy. However, salpingostomy is not always possible.
The operation will be performed under general anesthetic in one of two ways:
Laparoscopy: This is keyhole surgery involving minimal incisions. Recovery is about two to four weeks, though this varies from person to person.
Laparotomy: This is open surgery, which is used if severe internal bleeding is suspected. It involves a larger incision in the lower abdomen. Recovery is about four to six weeks, though this varies from person to person.
Ruptured ectopic pregnancy
An ectopic pregnancy may rupture the fallopian tube, leading to heavy bleeding, which can cause serious medical problems and may, occasionally, be life-threatening. Ruptured ectopic pregnancy requires emergency, life-saving surgery.
Symptoms of a rupture include: 1
- A sudden, intense stomach pain
- Dizziness or fainting
- Looking pale
- Rapid pulse
In surgery, the ruptured Fallopian tube and remnant of the ectopic pregnancy are removed.
Ectopic pregnancy treatment complications
There are some possible, but very rare complications after surgery, as well as side effects from taking methotrexate. A doctor will discuss these with the person affected by ectopic pregnancy, before commencing treatment. 1
Persistent ectopic pregnancy
A persistent ectopic pregnancy may occur, in which some ectopic cells are left behind and continue to grow, or further ectopic pregnancies occur.
If there is no history of diseases of the fallopian tubes, the chances of having another ectopic pregnancy may not be much higher than in a person who has not previously had an ectopic pregnancy.
If a person has some of the risk factors for ectopic pregnancy, as listed above, then the risk of problems in the future increases.
Fertility problems following ectopic pregnancy
Most women will make a full recovery from ectopic pregnancy and will be able to conceive normally in future.
Rarely, fertility may be affected, especially in the case of ruptured ectopic pregnancy or if a fallopian tube is removed in treatment.
If treatment has involved any kind of surgery, the risk of fertility problems is higher than if medical treatment or no treatment was needed. 1
Ectopic pregnancy and emotions
It is normal to feel distressed after an ectopic pregnancy. It can mean coming to terms with the loss of a baby, with a potential impact on future fertility or, for some, with the thought of having nearly lost their life. In some people, these emotions can develop into depression and anxiety if left untreated.
According to the Miscarriage Association, a person with ectopic pregnancy may be emotionally affected in a variety of ways, including: 13
Shock: A person may experience shock about the diagnosis, especially in cases where there has been emergency surgery or about what might have happened without diagnosis.
Loss and grief: It is normal to feel grief for the baby that was expected.
Feeling ‘in limbo’ and unable to move on: It is common to feel frustrated at having to wait some time before being able to try again and having to have follow-up and repeated blood and urine tests.
Counseling is available for people affected by an ectopic pregnancy. Support groups are also available and may be able to put a person in touch with others in a similar situation.
A health professional will be able to provide advice on choosing the most appropriate kind of support for a person, couple or family who has experienced an ectopic pregnancy.
Q: How common is ectopic pregnancy?
A: About one in 50 pregnancies are ectopic. 14 Many early ectopic pregnancies resolve on their own, without treatment. Some ectopic pregnancies will resolve before they produce symptoms.
Q: Can a person have an ectopic pregnancy with a copper coil (IUD)?
A: IUDs ensure a very low risk of any pregnancy, either intrauterine or ectopic. However, if a person does conceive, the probability of the pregnancy being ectopic is higher than in women not using an IUD. 3 An IUD is still more protective against ectopic pregnancy than not using contraception. 14
Q: Can a person have an ectopic pregnancy with IVF?
A: Yes, in vitro fertilization puts a person at higher risk of ectopic pregnancy. It may increase the occurrence of unusual types of ectopic pregnancies, such as heterotopic pregnancy, in which there is simultaneous intrauterine and tubal pregnancies, and interstitial pregnancy, which occurs in the part of the fallopian tube embedded in the uterus wall. 15
Q: Is it possible to miscarry an ectopic pregnancy?
A: In the very early stages, the fetus may pass out of the cervix on its own, without the need for further treatment. This may result in some symptoms of miscarriage being present. As the fetus develops, it becomes less likely that it will pass out of the womb on its own, and medical or surgical management will be needed to remove it. However, the techniques used to treat ectopic pregnancy may differ from those used to treat incomplete miscarriage. See this resource on miscarriage for more information.
Q: Is prevention of ectopic pregnancy possible?
A: Preventing ectopic pregnancy is not normally possible. Adequate use of contraceptives significantly reduces the risk of ectopic pregnancy. A person may be able to prevent a tubal pregnancy in the fallopian tube, if things that scar the tube, such as smoking and exposure to sexually transmitted diseases (STDs), can be avoided.
In some cases of ectopic pregnancy, a person may have surgery to remove the tube containing the ectopic pregnancy, which will reduce the risk of further ectopic pregnancies or persistent ectopic pregnancy. This occurs if some ectopic cells are left behind and continue to grow, or if there are subsequent ectopic pregnancies.
Other names for ectopic pregnancy
- Extrauterine pregnancy
- Tubal pregnancy
- Interstitial pregnancy
- Cervical ectopic pregnancy
- Ovarian ectopic pregnancy
- Cesarean scar ectopic pregnancies
- Intramural pregnancy
- Abdominal pregnancy
- Heterotopic pregnancy