What an ectopic pregnancy is
In an ectopic pregnancy, a fertilised egg implants outside the womb, usually in one of the fallopian tubes that connect the ovaries to the womb. A tube cannot hold a growing pregnancy: the egg will not develop into a baby, and the person's health may be at risk if the pregnancy continues. The NHS is clear that the pregnancy cannot be saved and usually has to be removed with medicine or an operation (NHS, Ectopic pregnancy).
It is not rare. According to the NHS, around 1 in every 90 pregnancies in the UK is ectopic, which is around 11,000 pregnancies a year.
Why it happens
Often there is no clear reason; sometimes the tube is narrowed or blocked. The NHS lists the following as associated with a higher risk:
- pelvic inflammatory disease, an inflammation of the reproductive organs usually caused by a sexually transmitted infection;
- a previous ectopic pregnancy, after which the risk of another is around 10%;
- previous surgery on the fallopian tubes, such as an unsuccessful sterilisation;
- fertility treatment such as IVF, because medicines that stimulate ovulation can increase the risk;
- becoming pregnant with an intrauterine device (coil) or intrauterine system in place, which is rare but, when it happens, more often ectopic;
- smoking, and increasing age, with the risk highest over 35.
Risk factors do not tell the whole story. The NICE guideline on ectopic pregnancy and miscarriage (NG126) reminds clinicians that about a third of women with an ectopic pregnancy have no known risk factor, so the diagnosis has to be considered even when nothing in a person's history points to it. Of the risks that can be changed, the NHS mentions two: using condoms when not trying for a baby, to protect against infections, and stopping smoking, which is also part of the advice in what the official guidance recommends before trying for a baby.
The warning signs
An ectopic pregnancy does not always cause symptoms and may only be found at a routine scan. When symptoms appear, they tend to develop between the 4th and 12th weeks of pregnancy. The NHS lists a combination of:
- a missed period and other signs of pregnancy;
- tummy pain low down on one side, which may come on suddenly or gradually;
- vaginal bleeding or a brown, watery discharge, which often starts and stops and can be mistaken for a period;
- pain in the tip of the shoulder, where the shoulder ends and the arm begins, which can be a sign of internal bleeding;
- discomfort when peeing or pooing.
Each of these can have harmless causes, such as a stomach bug. The NHS advises contacting a GP or calling NHS 111 if you have a combination of these symptoms and might be pregnant, even if you have not had a positive pregnancy test. NICE warns professionals that atypical presentations are common, and that the symptoms can resemble those of gut or urinary infections.
When it is an emergency
Occasionally the pregnancy grows large enough to split the fallopian tube open. This is called a rupture and needs surgery as soon as possible. Call 999 or go straight to A&E if you have a combination of:
- sharp, sudden and intense pain in the tummy;
- feeling very dizzy or fainting;
- feeling sick;
- looking very pale.
The NHS stresses that ruptures are uncommon and treatable if dealt with quickly, and that deaths from them are extremely rare in the UK. The same emergency signs appear in our guide to miscarriage, because bleeding with severe pain in early pregnancy always needs urgent assessment, whatever the cause turns out to be.
How it is diagnosed
Symptoms alone are not enough to make the diagnosis. A GP will usually offer a pregnancy test and, if it is positive and symptoms fit, refer to an early pregnancy assessment service. There, two tests do most of the work.
A transvaginal ultrasound scan, with a small probe placed in the vagina, is the main tool. NICE NG126 lists which scan features confirm a tubal ectopic pregnancy and which only raise the suspicion, such as an empty womb. Very early on, the pregnancy may be too small to see anywhere.
That situation has a name: a pregnancy of unknown location. NICE asks clinicians to treat it as a possible ectopic pregnancy until the location is known. The second tool is then blood tests for hCG, the pregnancy hormone, taken as near as possible to 48 hours apart. NICE says hCG cannot show where a pregnancy is, but the change between the two results guides what happens next:
- a rise of more than 63% in 48 hours suggests a developing pregnancy in the womb, although an ectopic pregnancy is not excluded, and a scan follows;
- a fall of more than 50% suggests the pregnancy is unlikely to continue, and a urine pregnancy test 14 days later checks that it has ended;
- anything in between leads to a clinical review within 24 hours.
NICE asks clinicians to give more weight to symptoms than to hCG results. If the picture is still unclear, a laparoscopy (keyhole surgery under general anaesthetic) can look at the tubes directly and remove an ectopic pregnancy in the same operation.
The three treatment options
Which treatment is offered depends on symptoms, the size of the pregnancy on the scan and the hCG level. NICE NG126 sets out the thresholds that NHS services use (NICE NG126, Management of tubal ectopic pregnancy).
- Expectant management (careful monitoring). Many very early ectopic pregnancies resolve on their own. NICE recommends offering this to women who are stable and pain free, with a tubal pregnancy smaller than 35 mm and no visible heartbeat, an hCG level of 1,000 IU/L or less, and who can come back for follow-up; it can be considered up to 1,500 IU/L. hCG is rechecked on days 2, 4 and 7 and then weekly until it is negative. On limited evidence, NICE says outcomes appear similar to those after medicine.
- Methotrexate. A single injection of this medicine stops the pregnancy growing. NICE recommends offering it when there is no significant pain, the mass is smaller than 35 mm with no heartbeat, hCG is below 1,500 IU/L, a pregnancy in the womb has been ruled out, and follow-up is possible. Between 1,500 and 5,000 IU/L, patients can choose between methotrexate and surgery, knowing that medicine is more likely to need further treatment. hCG is checked on days 4 and 7, then weekly. The NHS advises reliable contraception for at least 3 months afterwards, because the medicine can harm a baby conceived during that time.
- Surgery. NICE recommends surgery first when there is significant pain, a mass of 35 mm or more, a visible fetal heartbeat or an hCG level of 5,000 IU/L or more, and for anyone who cannot return for follow-up. It should be done by keyhole surgery whenever possible. The usual operation, a salpingectomy, removes the affected tube; a salpingotomy removes the pregnancy but keeps the tube and is considered when there are other risks to fertility, such as damage to the other tube. NICE says up to 1 in 5 women who have a salpingotomy may need further treatment. A ruptured tube needs emergency open surgery.
People who are rhesus negative (D-negative), were at least 12 weeks pregnant and have medical or surgical treatment are usually offered an anti-D injection to protect future pregnancies.
Recovery and the next pregnancy
After keyhole surgery most people leave hospital within a few days, although full recovery can take 4 to 6 weeks. The grief can last for months, for partners too; a GP can refer for counselling, and the NHS points to charities including the Ectopic Pregnancy Trust and Miscarriage UK.
The outlook for a future pregnancy is generally good. The NHS says most women who have had an ectopic pregnancy can get pregnant again, even if a tube has been removed, although some will need fertility treatment such as IVF. The usual advice is to wait for at least two periods before trying again, and at least three months after methotrexate. Because the risk of a repeat ectopic pregnancy is higher, tell a GP as soon as you are pregnant again; NICE adds that women can refer themselves to an early pregnancy assessment service in future pregnancies if they have any concerns.
This article summarises NHS information and the NICE guideline used in England. It is not personal medical advice. If you might be pregnant and have pain on one side, bleeding or shoulder tip pain, contact your GP or NHS 111, and call 999 for severe pain, fainting or dizziness.