- What is an ectopic pregnancy?
- How does it happen?
- Can an ectopic pregnancy survive?
- How is it diagnosed?
- What is the treatment?
- What are the chances of a second ectopic pregnancy?
- When to see a doctor
What is an ectopic pregnancy?
The word ectopic means displaced, and an ectopic pregnancy is one which grows somewhere other than its normal site, ie. the womb (uterus). Often referred to as a tubal pregnancy, this is a potentially dangerous condition in which the pregnancy fails to reach the womb and embeds itself into the wall of the Fallopian tube. Although it is a rare condition, occurring approximately once in every 350 pregnancies, it can be a very painful and distressing experience for a woman. Women who have damaged Fallopian tubes, eg. as a result of infections, are at higher risk of having an ectopic pregnancy.
How does it happen?
On the seventh day after fertilisation, the ovum or egg will have developed special protrusions on its outer side called chorionic villi. These enable the pregnancy to embed itself within whatever maternal tissue is nearest or most convenient at the time. If the newly-fertilised egg has not reached the womb within seven days it will embed itself into the wall of the Fallopian tube and become an ectopic or tubal pregnancy.
Can an ectopic pregnancy survive?
The short answer is no, it is always doomed to failure. The Fallopian tube is relatively thin compared to the thick, spongy muscle bed of the uterus where the pregnancy is meant to grow. As the pregnancy advances, it stretches the outer wall of the tube which will eventually burst causing acute pain and internal bleeding if the condition is undiagnosed. If untreated this could be potentially fatal to the woman.
How is it diagnosed?
In its early stages, it is impossible to differentiate between an ectopic pregnancy and one which is situated normally within the cavity of the uterus as both pregnancies produce exactly the same hormones.
One of the first indications that something may be going wrong with the pregnancy is the sudden onset of sharp pain low down in one side of the abdomen. This is due to the stretching of the Fallopian tube as the pregnancy grows. Any women in the early stages of pregnancy who experiences severe pain which is confined to only one side of her abdomen and is situated low down should contact her GP or antenatal clinic immediately. Many, but not all, women with an ectopic pregnancy will also experience vaginal bleeding, although it is rarely heavy bleeding and is often described as a period.
These symptoms may occur in a woman who may not be aware she is pregnant as her period may only be a week or two overdue.
Occasionally, the first warning of an ectopic pregnancy is sudden, severe lower abdominal pain and collapse, due to the rupture of the Fallopian tube in which the pregnancy has implanted. This requires urgent treatment.
If an ectopic pregnancy is suspected, a pregnancy test will be carried out, if one has not already confirmed a pregnancy. An ultrasound scan is helpful in the diagnosis. The diagnosis will generally be confirmed by a laparoscopic examination. This entails inserting a viewing tube through the abdominal wall under anaesthesia to view the uterus and tubes.
What is the treatment?
If an ectopic pregnancy is confirmed at laparoscopy, there are a number of treatment options, depending on the precise situation.
If the ectopic pregnancy has ruptured the tube or is in imminent danger of doing so, the tube and pregnancy are surgically removed. In some cases where the ectopic pregnancy has not ruptured, the tube may be opened, the ectopic removed and the tube repaired, all via the laparoscope. This method of treatment may be used when the ectopic is diagnosed early, or when there is only one tube remaining and preservation of fertility is important.
If the ectopic pregnancy is diagnosed at an early stage, medical treatment with a drug to cause the pregnancy to be reabsorbed may be possible. This requires careful follow up with repeated blood tests to ensure that it has been successful.
What are the chances of a second ectopic pregnancy?
The complete removal of an otherwise healthy Fallopian tube after an ectopic pregnancy naturally leads to anxiety about future fertility, but most women in this position happily go on to conceive and carry a normal pregnancy to full-term as their second tube is still functioning.
While the incidence of an ectopic pregnancy occurring in the remaining Fallopian tube is rare, it does happen in roughly 10 per cent of cases with a previous history of the condition.
The best advice to any woman with a history of ectopic pregnancy is to see her GP or visit the antenatal clinic as soon as she discovers she is pregnant. Ultrasound scanning will confirm that the pregnancy is in the right place.
When to see a doctor
A visit to the GP is strongly advised for any woman with a combination of any of the following symptoms:
- Missed period and/or a positive pregnancy test.
- Abdominal pain which occurs on one side only and is situated low down in the abdomen.
- Vaginal bleeding which starts after a bout of lower abdominal pain.
- Those with an IUD (coil) in place, are taking the progestogen-only pill, or have had previous pelvic inflammatory disease or ectopic pregnancy. All of these make the possibility of an ectopic pregnancy more likely.
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