In the early stages of pregnancy, an egg is released from one of your ovaries into one of your fallopian tubes, where it is fertilised by sperm.

Each fallopian tube is about 10cm (4 inches) long and lined with millions of moving, hair-like structures called cilia. In a normal pregnancy, the cilia push the fertilised egg along the tube and into the womb, where the egg implants itself into the womb’s lining (endometrium) and develops into a baby.

However, if the fallopian tube has been damaged (for example, if there is a blockage or narrowing of the tube), the cilia may not be able to move the egg to the womb, and the pregnancy may develop in the fallopian tube.

Common risk factors

Some of the most common risk factors for an ectopic pregnancy are discussed below.

Pelvic inflammatory disease

Pelvic inflammatory disease (PID) is a bacterial infection of the female reproductive system. Most cases of PID are caused by an infection in the vagina or the neck of the womb (cervix) that has spread to the reproductive organs higher up.

Many different types of bacteria can cause PID, but most cases are due to a chlamydia infection – this is a type of sexually transmitted infection that can be spread during unprotected sex.

Chlamydia often exhibits no noticeable symptoms, so women may not know they are infected. However, the bacteria can cause inflammation of the fallopian tubes, which is known as salpingitis. Salpingitis leads to a four-fold increase in the risk of having an ectopic pregnancy.

Previous history

Having a previous history of ectopic pregnancy means you have an increased risk of having one in the future.

Depending on the underlying factors, the risk of having another ectopic pregnancy is somewhere between 1 in 10 and 1 in 4.

Previous surgery

If you have ever had surgery that involved your fallopian tubes, you have an increased risk of having an ectopic pregnancy. Types of surgery known to increase your risk include:

• female sterilisation (a type of surgery known as tubal ligation or “tying the tubes”) – in around 1 in 200 cases surgery fails, the woman becomes pregnant and can result in an ectopic pregnancy
• earlier surgery to remove a previous ectopic pregnancy

Fertility treatments

Taking medication to stimulate ovulation (the release of an egg) can increase the risk of ectopic pregnancy by around four-fold.

The type of fertility treatment known as in-vitro fertilisation (IVF) is not always successful and can accidentally result in an ectopic pregnancy.

This occurs in around 1 in 22 cases of IVF.

Contraception

The intrauterine device (IUD) and the intrauterine system (IUS) are very effective in preventing pregnancy – the success rate is estimated to be around 99 out of 100 cases. But if a pregnancy does occur when using these types of contraception, it is more likely to be an ectopic pregnancy than a normal pregnancy.

There is also a risk that if you take emergency contraception and it fails to work, any subsequent pregnancy could be an ectopic pregnancy.

Other risk factors

Other potential risk factors for an ectopic pregnancy include:

• structural problems – ectopic pregnancy is more likely if you have an abnormally shaped fallopian tube
• smoking – smokers are twice as likely to have an ectopic pregnancy than non-smokers
• being aged over 35

To avoid complications, it’s important that an ectopic pregnancy is diagnosed as early as possible.

Physical complications

In the UK, many women who have an ectopic pregnancy receive early diagnosis and treatment – as a result, they don’t have any physical complications.

Some early pregnancy clinics will use an ultrasound scan to screen women thought to be at increased risk of having an ectopic pregnancy. People at risk include those that have a previous history of ectopic pregnancy or pelvic inflammatory disease.

The most common physical complications are described below.

Another ectopic pregnancy

The later an ectopic pregnancy is diagnosed and treated, the more likely it is that your fallopian tubes will be damaged. If this happens, you’re more likely to have another ectopic pregnancy in the future.

Rupture

You are also more likely to have a ruptured ectopic pregnancy (when the fallopian tube splits) and severe internal bleeding, which can lead to shock (when your blood pressure suddenly drops to a dangerously low level).

In very rare cases, this can be fatal. There are around three deaths a year in England that are the result of an ectopic pregnancy.

Infertility

Around 65% of women have a successful pregnancy 18 months after experiencing an ectopic pregnancy.

The emotional impact of an ectopic pregnancy

The loss of a pregnancy can have a profound emotional impact – not only on the woman herself, but also on her partner, friends and family.

The most common emotions that are felt after an ectopic pregnancy are grief and bereavement.

Physical symptoms of grief and bereavement include:

• fatigue (tiredness)
• loss of appetite
• difficulties concentrating
• sleeping problems

Emotional symptoms of grief and bereavement include:

• guilt
• shock and numbness
• anger (sometimes at a partner, or at friends or family members who have had successful pregnancies)
• an overwhelming sense of sadness and distress

These types of symptoms are often at their worst four to six weeks after the loss of pregnancy, before gradually improving, but it can sometimes take up to 12 months for feelings such as distress to pass.

Getting support

If you are worried that you or your partner are having problems coping with grief, you may need further treatment and counselling. Support groups can provide or arrange counselling for people who have been affected by loss of a pregnancy.

Read more about dealing with loss and counselling.

You can also find bereavement support services in your area.

Your GP can give you support and advice, and the following organisations can also help:

• The Ectopic Pregnancy Trust – who have a weekday helpline (10am-4pm) on 020 7733 2653, as well as an online message board where you can talk to other people affected by ectopic pregnancy
• The Ectopic Pregnancy Foundation – provides information on research into the different medical aspects of ectopic pregnancy
• The Miscarriage Association – a charity that offers support to people who have lost a baby. Call them on 01924 200 799 (Monday-Friday, 9am-4pm) or email them on info@miscarriageassociation.org.uk to be put in touch with a support volunteer
• Cruse Bereavement Care – helps people understand their grief and cope with their loss. Call their helpline on 0844 477 9400 (Monday-Friday, 9am-5pm). They also have a network of local branches, where you can find support

It’s difficult to diagnose an ectopic pregnancy from the symptoms alone, as they can be similar to other conditions.

Your GP may examine you and offer a pregnancy test. If you have the symptoms of an ectopic pregnancy and a positive pregnancy test, you may be referred to a an early pregnancy assessment service for further testing.

Some of these tests are outlined below.

Blood tests

If you start to have symptoms of an ectopic pregnancy a few weeks into your pregnancy, you may be offered a blood test to measure blood levels of the hormone human chorionic gonadotropin (hCG), which is produced by placental tissue.

The hCG levels are usually lower than normal if your pregnancy is ectopic, or you’re going to have a miscarriage.

Read more information about blood tests.

Vaginal ultrasound

An ectopic pregnancy is usually diagnosed by carrying out a transvaginal ultrasound scan.

This uses high-frequency sound waves to create an image of your reproductive system.

A small probe is inserted into your vagina, to take a close-up image of your womb and surrounding areas. It will usually show the location of your pregnancy.

Laparoscopy

If a diagnosis of ectopic pregnancy has still not been confirmed, a laparoscopy may be performed.

This is a direct examination of the womb and fallopian tubes using a viewing tube (a laparoscope), which is passed through a small opening in the wall of your abdomen.

The procedure is done under general anaesthetic (meaning you are put to sleep).

Scan

Ultrasound scans are a way of producing pictures of inside the body using sound waves.

An ectopic pregnancy is when a fertilised egg implants itself outside of the womb, usually in one of the fallopian tubes.

This means the egg will not develop into a baby, which can be devastating to the pregnant woman.

Occasionally, an ectopic pregnancy doesn’t cause any noticeable symptoms and is only detected during routine pregnancy testing. However, most women do have symptoms, and these usually become apparent between week 5 and week 14 of pregnancy.

They include:

• abnormal vaginal bleeding
• abdominal pain, typically just in one side, which can range from mild to severe
• an absent period (amenorrhoea), and other symptoms of pregnancy 

Read more about the symptoms of an ectopic pregnancy.

How is an ectopic pregnancy treated?

If an ectopic pregnancy is detected at an early stage, a medication called methotrexate is sometimes needed to stop the egg developing. The pregnancy tissue is then absorbed into the woman’s body.

However, methotrexate is not always needed – in around half of cases, the egg dies before it can grow.

Ectopic pregnancies detected at a more advanced stage will require surgery to remove the egg.

If an ectopic pregnancy is left to develop, there is a risk that the fertilised egg could continue to grow and cause the fallopian tube to split open (rupture), which can cause life-threatening internal bleeding.

Signs of a ruptured fallopian tube are:

• sudden, severe, sharp pain
• feeling faint and dizzy
• feeling or being sick
• diarrhoea
• shoulder tip pain

A ruptured fallopian tube is a medical emergency. If you think that you or someone in your care has experienced this complication, call 999 and ask for an ambulance.

Read more about treating ectopic pregnancy.

Why does an ectopic pregnancy happen?

In a normal pregnancy an egg is fertilised by sperm in one of the fallopian tubes, which connect the ovaries to the womb. The fertilised egg then moves into the womb and implants itself into the womb lining (endometrium), where it grows and develops.

An ectopic pregnancy occurs when a fertilised egg implants itself outside the womb. It most commonly occurs in a fallopian tube (this is known as a tubal pregnancy), usually as the result of damage to the fallopian tube or the tube not working properly.

Less commonly (in around 2 in 100 cases), an ectopic pregnancy can occur in an ovary, in the abdominal space or in the cervix (neck of the womb).

Things that increase your risk of ectopic pregnancy include:

• pelvic inflammatory disease (PID) – an infection of the female reproductive system, typically caused by chlamydia
• smoking
• having a previous history of other ectopic pregnancies

In around half of all cases, there are no obvious risk factors.

Read more about the causes of, and risk factors for, an ectopic pregnancy.

Support

Losing a pregnancy can be devastating and many women feel the same sense of grief as if they had lost a family member or partner.

It is not uncommon for feelings of grief and bereavement to last for 6-12 months, although these feelings usually improve with time.

Many women affected by an ectopic pregnancy benefit from counselling. Read more about dealing with loss and the emotional impact of ectopic pregnancy.

Trying for another pregnancy

How long it is advisable to wait before you try for another pregnancy will depend on your specific circumstances. Your doctor should be able to advise you when (or if) it will be safe to do so.

In most cases it is recommended that you wait for at least two full menstrual cycles before trying for another pregnancy, as this will allow time for your fallopian tubes to recover. However, if you were treated with methotrexate, it is usually recommended that you wait at least three months.

However, many women are not emotionally ready to try for another pregnancy so soon.

Your chances of having a successful pregnancy will depend on the underlying health of your fallopian tubes. In general, 65% of women achieve a successful pregnancy 18 months after having an ectopic pregnancy.

If you cannot conceive in the normal way, then fertility treatment such as in-vitro fertilisation (IVF) may be an option.

IVF treatment is where an egg is fertilised by a sperm outside the womb (usually in a test tube) and, after fertilisation, the embryo is surgically implanted into the womb.

Who is affected

It is estimated that around 1 in 90 pregnancies in the UK develops into an ectopic pregnancy. This is around 10,700 pregnancies a year.

Nowadays, deaths from ectopic pregnancies are extremely rare.

Cervix

The cervix is at the lower end of the womb. It connects the womb with the vagina.

Fallopian tubes

Fallopian tubes (also called oviducts or uterine tubes) are the two tubes that connect the uterus to the ovaries in the female reproductive system.

Ovaries

Ovaries are the pair of reproductive organs that produce eggs and sex hormones in females.

You cannot always prevent an ectopic pregnancy, but you can reduce your risk of having one by protecting yourself against pelvic inflammatory disease (PID).

Pelvic inflammatory disease (PID) is thought to be the leading cause of ectopic pregnancies, as it can damage your fallopian tubes.

PID is usually caused by a sexually transmitted infection (STI) such as chlamydia or gonorrhoea, which starts in the vagina and spreads to the reproductive organs higher up.

Preventing STIs

The male condom is the most effective method of preventing sexually transmitted infections (STIs). It’s also important to have regular sexual health check-ups:

• when you start a relationship with a new partner
• after having unprotected sex
• after having sexual contact with someone who you think may have been infected with an STI
• if you experience any symptoms of an STI

You can have a sexual health check-up by visiting your local genito-urinary medicine (GUM) or sexual health clinic. To find your local clinic, see the NHS Choices service directory.

Read more about the health benefits associated with using a condom and safe sex.

Quitting smoking

Stopping smoking will also lower your risk of ectopic pregnancy as well as many other serious health conditions, including lung cancer, stroke and heart disease.

If you decide to stop smoking, your GP can refer you to an NHS Stop Smoking Service, which will provide you with dedicated help and advice about the best ways to give up smoking. You can also call the NHS Stop Smoking Helpline on 0300 123 1014 (England only). The specially trained helpline staff can give you free expert advice and encouragement.

If you are committed to giving up smoking but don’t want to be referred to a stop smoking service, your GP should be able to prescribe medical treatment to help with any withdrawal symptoms you may have after giving up.

For more information about giving up smoking, read our pages on treatment for quitting smoking and stopping smoking.

The Map of Medicine is used by doctors throughout the NHS to determine the best treatment options for their patients. NHS Choices offers everyone in England exclusive and free access to this cutting-edge internet resource, which lets you see exactly what your doctor sees.

The information in the Map has been approved by the UK’s leading clinical experts, is based on the best available clinical evidence, and is continually updated. To take advantage of this unique resource go to:

Map of Medicine: ectopic pregnancy

Some women who have an ectopic pregnancy do not have any symptoms. They may not find out it is ectopic until an early scan shows the problem or a woman’s fallopian tube has ruptured.

If there are symptoms, they usually appear between weeks 5 and 14 of the pregnancy. These are outlined below.

Common symptoms

One-sided abdominal pain

You may experience pain, typically on one side of your abdomen (tummy), which can be persistent and severe.

Vaginal bleeding

Vaginal bleeding is a different type of bleeding from your regular period. It often starts and stops, and can be bright or dark red in colour. Some women mistake this bleeding for a regular period and do not realise they are pregnant.

Less common symptoms

Shoulder tip pain

Shoulder tip pain is felt where your shoulder ends and your arm begins. It’s not known exactly why shoulder tip pain occurs, but it usually happens when you’re lying down and is a sign that the ectopic pregnancy is causing internal bleeding.

The bleeding is thought to irritate the phrenic nerve, which is found in your diaphragm (the muscle used during breathing that separates your chest cavity from your abdomen). Irritation of the phrenic nerve causes referred pain (pain that is felt elsewhere) in the shoulder blade.

Bowel pain

You may experience pain when passing urine or stools.

Diarrhoea and vomiting

An ectopic pregnancy can cause similar symptoms to a gastrointestinal disease and is often associated with diarrhoea and vomiting.

When to seek medical advice

You should always contact your GP if:

• you notice a change to your normal pattern of menstruation
• you have unusual vaginal bleeding and/or
• you have persistent abdominal pain

When to seek emergency medical treatment

The most serious symptom of an ectopic pregnancy is known as “collapse”. This occurs when an ectopic pregnancy has split open the fallopian tubes (tubal rupture) and is causing dangerous internal bleeding.

People who have experienced collapse describe feeling lightheaded (dizzy) and faint. You may also:

• experience a sharp, sudden, intense abdominal pain
• feel sick
• have an increased heart rate
• look pale
• have diarrhoea

If your fallopian tubes rupture, you will need emergency surgery to prevent blood loss. Dial 999 immediately and ask for an ambulance.

In rare cases, a ruptured fallopian tube can be fatal. However, this is very uncommon and in most cases, the fallopian tube can be successfully repaired or removed.

The baby cannot be saved in an ectopic pregnancy.

If the ectopic pregnancy is diagnosed before your fallopian tube ruptures, you have the following treatment options:

• active monitoring – where you receive no immediate treatment but your condition is carefully monitored
• medication – a medicine called methotrexate can be used to stop the ectopic pregnancy growing 
• surgery – surgery can be used to remove the egg

Your specialist or gynaecologist can advise you on the benefits and risks of each option.

Active monitoring

If you are only experiencing mild symptoms, there is a chance that the pregnancy will resolve itself. The fertilised egg will die and then be absorbed into nearby tissue, without the need for treatment.

This is more likely if your blood tests show low levels of the human chorionic gonadotropin (hCG) hormone.

Should you decide on this option, you will still need to have regular blood tests and, in some cases, ultrasound scans to assess the pregnancy’s progress.

If tests do not show a continued drop in hCG levels, you will need more treatment (this usually happens in around one in three cases treated using active monitoring).

The advantage of active monitoring is that you won’t have to experience any side effects of treatment.

A disadvantage is that there is still a small risk of your fallopian tubes splitting open (tubal rupture), even if blood tests show low levels of the hCG hormone.

Methotrexate

If an ectopic pregnancy is growing but is diagnosed early enough, it can be ended using a medicine called methotrexate.

Methotrexate works by stopping the embryo cells growing. It is usually only suitable if the ectopic pregnancy:

• is no larger than 3.5cm in diameter, with no visible heartbeat
• is not causing a lot of pain
• has a serum hCG level less than 1500 IU/litre
• has no intrauterine pregnancy (as confirmed by an ultrasound scan)

Methotrexate may also not be suitable if you have one or more of these:

• a condition known to weaken the immune system, such as diabetes
• any type of blood disorder that causes low levels of certain types of blood cells, such as anaemia
• liver disease
• kidney disease

If methotrexate is recommended, your condition will need to be closely monitored through regular blood tests after you have taken the medicine.

Methotrexate is usually given as a single injection into your buttocks, and a second dose is sometimes required.

You need to use reliable contraception for three to six months (depending on how many doses) after taking methotrexate. This is because there is an increased risk of developmental problems in your next baby if you become pregnant after being given the medication.

It is also important to avoid drinking alcohol until you are told it is safe to do so, as drinking soon after receiving a dose of methotrexate can damage your liver.

The most common side effect of methotrexate is abdominal pain, which usually develops a day or two after a dose is given. This pain is usually mild and should pass within 24-48 hours.

Other side effects can include:

• feeling sick
• being sick
• diarrhoea
• dizziness
• mouth ulcers

You will need to have blood tests around days four and seven after taking methotrexate. If the test doesn’t show a significant drop in hCG levels, you may need surgery.

There is still around a 1 in 14 chance of your fallopian tubes splitting open (rupture) after medical treatment with methotrexate, even if your hCG levels are going down. This means you need to be aware of the potential symptoms of a rupture – be ready to call an ambulance if you think one has happened.

Surgery

Surgery to remove the egg is the most common treatment for an ectopic pregnancy. Keyhole surgery (laparoscopy) is normally used.

This is where a tiny camera and surgical instruments are inserted through small cuts in your abdomen. This is done under general anaesthetic (meaning you will be asleep). If your other fallopian tube looks healthy, then the tube containing your ectopic pregnancy is usually removed (in a procedure known as a salpingectomy). This is the most effective treatment and does not reduce the chance of becoming pregnant again.

To avoid having two surgical procedures, surgery to remove an ectopic pregnancy or fallopian tube is sometimes done at the same time as a laparoscopy to confirm your ectopic pregnancy.

Your consultant will explain the chances of this happening before you go into hospital, and will ask if it is ok to remove your fallopian tubes, should this be necessary.

Most women can leave hospital a few days after surgery, although it can take up to a month before you fully recover.

If your fallopian tube has ruptured, you will need emergency surgery. The surgeon will make an incision in your abdomen (this is known as a laparotomy) to stop the bleeding and, if possible, repair your fallopian tube.

After surgery for an ectopic pregnancy, you should be offered a treatment called anti-D rhesus prophylaxis if your blood type is RhD negative (see blood groups for more information). This involves an injection of anti-D immunoglobulin, which helps prevent problems caused by rhesus disease in future pregnancies.

Follow up

Once your ectopic pregnancy has been treated, you may want to consider making a follow-up appointment with your GP.

Your GP should be able to discuss a number of issues, such as:

• what counselling services are available, if you feel you need this
• the likely impact your ectopic pregnancy and its treatment will have on your fertility
• when (or if) it is safe to try for another baby
• what options are available if your fallopian tubes have been damaged or removed