Ectopic pregnancy is one of the more serious complications of pregnancy and it is one of the most common reasons for an early pregnancy scan. An ectopic pregnancy happens when the products of fertilization implants and develops beyond the confines of the uterus.
Ectopic pregnancy is almost always not viable, except for very few instances. This condition can bring bleeding within the abdominal cavity which can be fatal for the mother. The most common form of ectopic pregnancy is one that takes places within the fallopian tubes, which is also called a tubal pregnancy. Other locations of implantation are the ovaries, cervix, and the abdomen. As has been mentioned, this condition can bring bleeding and death, and as such should be treated as an emergency.
The course of a normal uterine pregnancy starts when the uterus receives the newly fertilized egg. The egg implants itself in the nutrient-rich uterine lining where it will eventually develop. On the other hand, in ectopic pregnancy, this process does not take place in the uterus: 98% of the time it happens in the Fallopian tubes.
With the current advances in diagnostic tools and procedures such as the early pregnancy scan, ectopic pregnancy can be detected and addressed earlier.
However, in spite of the diagnostic advances, this condition is still the main cause of morbidity and mortality among mothers all over the world. An increase in the incidence of ectopic pregnancy can be found in countries with substandard prenatal imaging and care.
Ectopic pregnancy takes place when the fertilized egg implants into the lining of the Fallopian tube. The egg eventually erodes into the surrounding blood vessels, bringing about bleeding. The bleeding that takes places within the Fallopian tube will push the egg out of the tube, ending up in what is called a tubal abortion. The Fallopian tube does not undergo inflammation in this case, and the pain is brought about by the prostaglandins present at the actual area of implantation and the irritation due to the presence of blood in the peritoneum.
When bleeding becomes more profuse, it can bring about the threat to the mother. While the common cause of the increase in bleeding is the delay in the diagnosis of ectopic pregnancy, some bleeding takes place a little faster. This is especially true when the implantation takes place in the proximal area of the Fallopian tube. In this case, the egg may eventually erode into the Sampson artery located in close proximity to the tube.
In 50% of cases, ectopic pregnancies resolve by itself, without intervention. This is especially true with tubal abortions. Currently, the need to perform the surgery has been drastically reduced with the introduction of methotrexate in the treatment of ectopic pregnancy. It should be remembered, though, that surgery will still have to be performed when the Fallopian tubes is near rupture or have already ruptured. Surgery may entail a limited incision via a laparoscopic method, or a larger incision may be used, in which case it is called a laparotomy.
Ectopic Pregnancy Signs and Symptoms
The early signs and symptoms of ectopic pregnancy are usually so subtle, if they are even present, which is why it is quite difficult to make an early diagnosis. The average time for the signs and symptoms of ectopic pregnancy to present themselves is about 7.2 weeks following the last menstruation, and the range is from 5 to 8 weeks. Diagnosis may come in even later for areas where facilities are insufficient.
The following are the early presentations of ectopic pregnancy:
Hypogastric pain accompanied by a sensation of swelling. The pain may be perceived as intense stomach pain, but the pain may also occur in the form of a strong cramping sensation.
Dysuria, or pain when urinating
A vague abdominal discomfort which is similar to symptoms brought about by the presence of corpus luteum in the ovary
Mild vaginal bleeding. This is a form of withdrawal bleeding, a phenomenon that occurs when progesterone levels go down. This symptom may also be noted during the early stage of pregnancy (also called “implantation bleed”) or during a miscarriage.
Abdominal pain during a bowel movement.
Later on, ectopic pregnancy presents itself as pain and bleeding, which may be vaginal or abdominal, or both. The causes of bleeding are as follows:
Hormonal trigger, i.e., a drop in the level of progesterone
• Peritoneal bleeding secondary to rupture of the Fallopian tube
Some of the differential diagnoses are miscarriage and normal pregnancy in its early stage. Pelvic inflammatory disease, or PID, is the most common faulty diagnosis for ectopic pregnancy. To rule out the presence of PID, a pregnancy test can be performed. A positive pregnancy test essentially rules out PID because a pregnancy that is concurrent with an active pelvic infection is very rare.
When bleeding becomes more profuse, the following symptoms may occur:
• Pain which may be located at the lower back, abdomen, and pelvis
• Shoulder pain. This is regarded as a dangerous sign because it indicates irritation of the diaphragm secondary to the blood that is filling up the abdomen.
• Unilateral pelvic tenderness and cramping sensation
• The pain is comparatively acute as opposed to other more chronic pelvic pain, which worsens with time.
Ectopic pregnancy should also be differentiated from other conditions like pelvic inflammatory disease, appendicitis, and other gynaecological, gastrointestinal, and urinary problems.
Ectopic Pregnancy Causes
While a number of risk factors for ectopic pregnancy have been identified in previous studies, no particular risk factor can be singled out in 30 to 50 per cent of cases. Infertility, smoking, endometriosis, a previous history of pelvic inflammatory disease, prior use of DES, a history of D & C or other uterine surgeries, tubal surgery, use of an IUD or intrauterine device, tubal ligation, and a history of ectopic pregnancy are just some of the risk factors enumerated.
Ectopic Pregnancy Treatment
Methotrexate has been used for the nonsurgical treatment of ectopic pregnancy since 1993. Methotrexate can halt the growth of the embryo, inducing either an abortion or resorption of the embryologic tissue or the passage of the products of conception during the woman's regular menstrual period. If administered early enough, methotrexate is effective in terminating ectopic pregnancy.
Surgical treatment may have to be initiated once bleeding has set in. In a patient with only little bleeding seen on ultrasound, however, the decision to perform surgery turns into a dilemma. Studies to back this up will have to be identified.
Two surgical procedures, laparoscopy and laparotomy, can be used by the surgeons. Both approaches can provide a visualization of the pelvis and the affected Fallopian tube. The tube can then be incised either by taking out only the portion where the embryo has implanted (salpingostomy) or by taking out the entire tube (salpingectomy). Robert Lawson Tait is credited for doing the first successful surgery for an ectopic pregnancy, which took place in 1883.
Author- Yianni Kiromitis PgC Medical Ultrasound, BSc(Hons) - Medical Ultrasound Practitioner
Specialities: Abdomen, Small Parts, Gynaecology/Obstetrics and Vascular...
Yianni Kiromitis is a London based NHS and Private Medical Sonographer, with more than 20 years’ experience in Healthcare.
Reviewed: 07/04/2020 by Yianni Kiromitis PgC Medical Ultrasound, BSc(Hons) and Tareq Ismail Pg (Dip) Medical Ultrasound, BSc(Hons)