Source: IVF-infertility
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Risks and complications of IVF treatment

Ectopic pregnancy

Ectopic pregnancy is a potentially life threatening condition. Ectopic pregnancy is a well-known but comparatively rare, complication of assisted conception treatments.

What is an ectopic pregnancy?

Ectopic pregnancy is any pregnancy that occur outside the cavity of the womb.

What is the incidence of ectopic pregnancy?

The reported incidence of ectopic pregnancy after IVF treatment varies between 2-11% of all pregnancies. This is much higher than is reported after natural conception, which is about 1 in 100 to 300 pregnancies. After one ectopic pregnancy, the risk of recurrence is between 10-20%.

In addition there is heterotopic pregnancy (a combined normal pregnancy and ectopic pregnancy). The incidence of heterotopic pregnancy after IVF is about 1% of all pregnancies compared with 2 in 30,000 after natural conception.

Where are the embryos most likely to implant in an ectopic pregnancy?

The commonest site of ectopic pregnancy is in the Fallopian tube (75-96%). Other less common sites include the ovary and cervix. Abdominal pregnancy is very rare, usually the fetus dies. However, occasionally it develops fully and survives, the delivery is performed by cutting the abdomen (laparotomy).

It is usual for the afterbirth (placenta) to be left over after the delivery of abdominal pregnancy, this is because it is usually fixed to the internal organs and removing it may results in damages to the these organs. These uncommon sites are very rarely encountered after natural conception compared to IVF pregnancies.

What are the causes of ectopic pregnancy?

This is not yet fully understood but the most common cause is a narrowed or distorted Fallopian tube. This could have been the consequence of past pelvic infections or operations, tubal surgery, previous ectopic pregnancy, adhesions or endometriosis. Occasionally there is a congenital abnormality of the tube.

It has been proposed that a damaged tube may be unable to expel the embryo, which may have been migrated into the tube from the uterine cavity and is trapped in the tube.

The technique of embryo transfer may contribute to the chance of ectopic pregnancy by forcing the embryo into the tube as a result of placing the embryo high in the cavity, injecting too much volume of the culture medium or injecting the embryos at high pressure. In most cases the cause of tubal pregnancy is not known.

Can ectopic pregnancy by prevented?

Unfortunately, ectopic pregnancy cannot be prevented. Complete tubal occlusion before starting IVF treatment was advocated by the pioneers of IVF, Mr Steptoe and Professor Edwards, following the first IVF pregnancy, which was ectopic. Although this practice may have helped to reduce the incidence of ectopic pregnancy, it is no longer performed. In addition it will not prevent an interstitial pregnancy, an ectopic pregnancy which implants in the inner part of the tube, which lies within the muscle of the womb.

What is the outcome of ectopic pregnancy?

Not all cases of ectopic pregnancies progress and pose a threat to the mother, in many cases the fetus dies and is absorbed. This is because there is either not enough space for the pregnancy to grow properly or the placenta can not form properly.

If the ectopic pregnancy does not die and carries on growing, the thin wall of the tube will stretch, causing pain in the lower abdomen. There may be some vaginal bleeding at this time. As the pregnancy grows, the tube may rupture; causing severe abdominal pain, internal bleeding and the patient may collapse.

What are the signs and symptoms of an ectopic pregnancy?

The presentation of ectopic pregnancy varies from that of an acute abdominal pain and shock to that of normal symptoms of pregnancy. Most patients present between the sixth and tenth weeks of pregnancy with lower abdominal pain, usually starting on one side. The pain then becomes severe and diffuses throughout the abdomen. There may or may not be vaginal bleeding or spotting. Shoulder tip pain may be felt with some ectopics due to the internal bleeding causing irritation of the diaphragm muscle.

Many cases of ectopic pregnancy are diagnosed in the emergency room, when the woman may be admitted with severe one-sided pelvic pain and possibly dizziness and faintness due to rupture of the tube and internal bleeding.

How is ectopic pregnancy diagnosed?

Unfortunately, to date, there is no available method of diagnosing ectopic pregnancy with 100% accuracy. A high index of suspicion in patients at risk is the cornerstone of early diagnosis. Recent advances in the measurement of blood beta hCG (the pregnancy hormone), progesterone and the development of high-resolution ultrasound scanning has greatly improved the early diagnosis of ectopic pregnancy and has made it possible to offer conservative treatment. A negative beta hCG result virtually excludes any risk of significant ectopic pregnancy. Several measurements of beta hCG over 48 hours may be performed to see if it is rising or falling.

Ectopic pregnancies not only tend to produce lower levels of these hormones than normal pregnancies, but the levels of these hormones also do not rise as rapidly. It is not always possible to see an ectopic pregnancy with an ultrasound scan, but the diagnosis of ectopic pregnancy is always suspected if the ultrasound scan showed an empty uterus but the pregnancy test is positive. Heterotopic pregnancies usually produce hormone levels similar to those of normal intrauterine pregnancies, and in these cases, a vaginal ultrasound scan (which gives a better image of the uterus, tubes and ovaries than abdominal scan), is the main tool for making the diagnosis.

Until recently, laparoscopy was the gold standard method for diagnosis of ectopic pregnancy and is still the method of choice where there is no facilities for performing the blood tests and ultrasound scanning, a laparoscopy will be advised to inspect the Fallopian tube and ovaries. In a severe emergency, for example if a patient collapse, a laparotomy will be needed and a blood transfusion may be required to replace blood loss.

How is ectopic pregnancy treated?

Several options exist for the treatment of ectopic pregnancy. The chosen treatment depends on the size and the site of ectopic pregnancy, the experience of the surgeon, the facilities available and the general condition of the patient.

The options include:

• Surgical treatment by laparoscopy or laparotomy.
• Medical treatment with drugs.
• Expectant treatment, awaiting the spontaneous resolution of the ectopic pregnancy.

If early diagnosis can be made before the tube is ruptured and the appropriate facilities are available, a less invasive procedure can be offered such a keyhole surgery or treatment with drugs. This may not only speed the recovery of the patient from the operation but may also increase the woman’s chance of future fertility. Fortunately, most ectopic pregnancies achieved after IVF treatment are diagnosed early.

Before the tube rupture, it may be possible for the surgeon, using the laparoscope to slit the tube, and remove the pregnancy leaving the tube intact (salpingotomy). Alternatively, a drug called Methotrexate, which prevents the rapid division of cells in early pregnancy, may be used. The drug is generally safe and effective and can cure the problem in about 70-95% of cases. About 2-20% of patients will experience some side effects. The drug can either be given directly into the ectopic pregnancy under ultrasound or laparoscopic guidance or injected intramuscularly and is absorbed into the blood stream and reaches the ectopic pregnancy. The risk of side effects is reduced when the drug is given locally into the ectopic pregnancy.

There are certain circumstances where methotrexate may be preferable to surgery. These include cervical pregnancy, where surgical intervention may be associated with a high risk of severe bleeding and in cases where ectopic pregnancy co-exists with ovarian hyperstimulation syndrome where the pelvic organs are vascular and surgical intervention may be better avoided. On the other hand, in heterotopic pregnancy, Methotrexate drug can not be given because it can damage the intrauterine pregnancy. Another drug so-called “potassium chloride” (KCL) can be injected directly into the ectopic pregnancy to stop the fetal heart.

It is now accepted that surgical treatment of ectopic pregnancy should be by laparoscope and should be as conservative as possible unless there are contraindications. Laparotomy and removal of the tube (salpingectomy) remains a necessity in emergency cases.

Expectant management of ectopic pregnancy is only recommended in selected cases when the patient is in stable condition with low hormones levels and a small ectopic. Spontaneous resolution occurs in about 70% of cases and can take up to 4 weeks. During this time the patient must have weekly blood tests to check the hormone levels and ultrasound scan.

Patients often ask whether their ectopic pregnancy could be taken out of the tube and replaced immediately into the womb. Unfortunately, this is not possible at present. Although the embryo may be normal, its blood supply can not regrow. It has been reported that half of the intrauterine components of the heterotopic pregnancies lead to live birth, the others aborted.

How does ectopic pregnancy affect future fertility and what are the chances of a repeat ectopic pregnancy?

Although the prime effect of an ectopic pregnancy is on the woman, the man too has to cope with the stress. It is advisable that before a patient tries for another pregnancy, she and her male partner should allow time to recover, both physically and emotionally. Feelings vary after ectopic pregnancy, with some women wanting to get pregnant immediately, while others find it difficult to cope with the stress and worry about another ectopic pregnancy happening. However, it is important that the woman should be made aware that, however terrifying and depressing the prospect of having another ectopic pregnancy might be, her chance of having a normal healthy pregnancy significantly exceeds that of having another ectopic pregnancy. It is also worth remembering that women who have had an ectopic pregnancy have at least proved their ability to get pregnant.

If one of the tubes ruptured or was removed, the woman will continue to ovulate as before but her fertility will be reduced by about 50%. Of those who get pregnant, the chances of a repeat ectopic pregnancy are between 7-10% depending on the type of treatment carried out and the condition of the remaining tubes. IVF treatment can help such patients. If a woman conceives spontaneously or by IVF, a careful watch must be kept for signs and symptoms of another ectopic pregnancy and, even if mild symptoms of another ectopic occur, they must be taken seriously.