An ectopic pregnancy is when a fertilised egg implants itself outside of the womb, usually in one of the fallopian tubes. This means the embryo will not be able develop into a baby as the fallopian tube is not large enough to support the growing embryo, which can be devastating to the pregnant woman.
In a few cases an ectopic pregnancy causes no noticeable symptoms and is only detected during routine pregnancy testing. However, most women do have symptoms and these usually become apparent between week 4 and week 12 of pregnancy.
Early diagnosis and treatment is important to prevent life-threatening bleeding and also, if possible, so the tube can be saved and it can continue to work.
Symptoms of ectopic pregnancy
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.
Shoulder tip pain - shoulder tip pain is felt where your shoulder ends and your arm begins. It is not known exactly why shoulder tip pain occurs, but it usually occurs when you are 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). The irritation to 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.
How is ectopic pregnancy diagnosed?
It can be difficult to diagnose an ectopic pregnancy from the symptoms alone, as they can be similar to other conditions.
Some of the tests used to diagnose an ectopic pregnancy include:
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.
Methotrexate is not always needed, as in around half of cases the egg dies before it can grow larger.
Ectopic pregnancies detected at a more advanced stage will require surgery to remove the pregnancy sac.
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 nauseous or vomiting
- 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 000 and ask for an ambulance.
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).
In many cases, it's not clear why a woman has an ectopic pregnancy. Sometimes it happens when there's a problem with the fallopian tubes, such as them being narrow or blocked.
The following are all associated with an increased risk of ectopic pregnancy:
- pelvic inflammatory disease (PID) - an infection of the female reproductive system, typically caused by chlamydia
- having a previous history of ectopic pregnancies
- previous surgery on your fallopian tubes - such as an unsuccessful female sterilisation procedure
- fertility treatment, such as IVF - taking medication to stimulate ovulation (the release of an egg) can increase the risk of ectopic pregnancy
- becoming pregnant while using an intrauterine device (IUD) or intrauterine system (IUS) for contraception - it's rare to get pregnant while using these, but if you do you're more likely to have an ectopic pregnancy
- increasing age - the risk is highest for pregnant women who are aged 35-40.
In around half of all cases, there are no obvious risk factors.
The loss of your pregnancy at any stage can have a huge impact on you and your partner. One day you are pregnant and planning your future life with your child, and then within a short time, your pregnancy ends. The ending of an ectopic pregnancy is a form of miscarriage – and the feelings that a woman and her partner may experience can be similarly difficult.
It is not uncommon for feelings of grief and bereavement to last for 6 to 12 months, although these feelings usually improve with time.
Pregnancy, Birth and Baby offers free and confidential support and counselling to women, their partners, friends and relatives. Call on 1800 882 436.
Many women affected by a miscarriage benefit from counselling. SANDS (miscarriage, stillborn and neonatal death support) provide support groups for parents and their family whose baby has died through stillbirth, neonatal death, miscarriage, ectopic pregnancy and medically advised termination.
Information on SANDS groups in Australian states can be obtained from the SANDS Australia website.
Trying for another pregnancy
It is normally recommended that you wait for at least 2 menstrual cycles before trying for another pregnancy, as this will allow time for your fallopian tubes to recover (if treated with methotrexate, you will need to wait at least 3 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.
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.
Last reviewed: August 2016