Definition and Overview

The fallopian tubes play a crucial role in conception and fertility. Fertilisation occurs in the ampulla of the fallopian tube when the egg comes in contact with sperm. When this happens, the fertilised egg stays in the fallopian tube for up to four days before being implanted in the uterus. There it attaches to the lining and continues to grow until the baby is born.

A tubal pregnancy occurs when the fertilised egg fails to reach the uterus and attaches itself in the fallopian tube, which does not have the ability to hold a growing embryo.

Tubal pregnancies are the most common type of ectopic pregnancy, a medical term used to describe a pregnancy that occurs outside of the uterus. About 2% of ectopic pregnancies develop in the ovaries, cervix or the intra-abdominal region.

Although some women are able to absorb their ectopic pregnancy without treatment, the condition is often treated with medications or surgery in cases where the patient’s life is at risk. If left untreated, the fallopian tube may rupture, which may lead to internal bleeding and hypovolemic shock, a life-threatening condition characterised by severe blood loss.

Ectopic pregnancies are uncommon accounting for just 1-2% of all live births worldwide. The risk is higher among those who have achieved pregnancy through assisted reproductive technology (ART) such as in vitro fertilisation.

Most ectopic pregnancies occur between seven and eight weeks after the last normal menstrual period. Thus, some patients are not even aware that they are pregnant and that they have subsequently absorbed their ectopic pregnancy. However, many seek medical attention due to abnormal vaginal bleeding, sharp or stabbing pain in the pelvis or abdomen, and gastrointestinal symptoms.

Causes of Condition

A tubal pregnancy occurs when the fertilised egg is blocked or slowed through the fallopian tube. According to research, this can be the result when hair-like fallopian cilia, which are responsible for carrying the fertilised egg to the uterus, are damaged. Damage to the fallopian cilia can be caused by smoking and pelvic inflammatory disease.

Other factors that can increase the risk of tubal pregnancy include:

  • Endometriosis

  • Intrauterine surgery

  • Previous ectopic pregnancy

  • Sexually transmitted diseases (STDs)

  • Tubal ligation/surgery

  • Unsuccessful tubal ligation or tubal ligation reversal

  • Use of fertility drugs

  • Use of intrauterine devices (IUDs)

  • A history of infertility

Key Symptoms

The classic signs of a tubal pregnancy are sharp or dull abdominal pain and vaginal bleeding, which are both experienced by more than 50% of patients. Other signs include pelvic pain, a tender cervix, diarrhoea, nausea, and vomiting. However, about 10% of patients have no symptoms while about 33% do not show medical signs.

A tubal pregnancy can be mistaken for other medical conditions that share the same symptoms, including miscarriage, appendicitis, urinary tract infection, and ovarian torsion.

If not diagnosed and treated promptly, the wall of the fallopian tube can rupture. This condition is a medical emergency as it can lead to significant internal bleeding.

Who to See and Types of Available Treatments

Doctors are able to diagnose a tubal pregnancy with a pregnancy test, pelvic ultrasound, and hCG blood test that checks for human chorionic gonadotropin, a hormone released during pregnancy. The diagnosis can then be confirmed with laparoscopy, which involves inserting specialised viewing instruments through small incisions in the abdominal wall to visualise the inside of the pelvis and the abdomen.

Treatment of tubal pregnancy depends on many factors. If the condition is found to be non-life-threatening and does not cause worrying symptoms, a wait-and-see approach is advised. Some women are able to spontaneously absorb their pregnancy without risk to their health. Doctors will closely monitor their condition by performing additional scans and blood tests. A declining hCG level is an indication that an ectopic pregnancy is self-resolving.

If a tubal pregnancy is caught very early and signs indicate that it is not going to resolve on its own, patients may avoid surgery by taking medications designed to terminate the growth of the developing embryo, which is then passed with a menstrual period or resorbed by the woman’s body. Those who qualify for this treatment are those who have stable haemodynamics, are not suffering from severe or persistent abdominal pain, and whose liver and renal function test results are normal. It is also important that patients are able to make numerous follow-ups with their doctor throughout the duration of treatment. Meanwhile, such medications are not recommended to patients who are immunodeficient, are currently breastfeeding, have active peptic ulcer disease, or suffering from thrombocytopenia or anemia.

If medication is not an option, such as in the case of later-term tubal pregnancy, surgery becomes necessary. This is the fastest treatment for ectopic pregnancy, regardless of its stage, and is the only one considered when internal bleeding is suspected.

An ectopic pregnancy can be removed from a fallopian tube by performing either salpingectomy or salpingostomy. Salpingectomy, which removes a part of the fallopian tube, is the procedure of choice if the fallopian tube is at risk of rupture or has already ruptured. Salpingostomy, on the other hand, involves making a lengthwise cut in the fallopian tube to remove the ectopic growth.

Both procedures can be performed via laparoscopy, a minimally invasive method that uses a laparoscope and specialised instruments that are inserted through small incisions in the abdominal wall. Guided by an imaging technology, the doctor will remove the ectopic pregnancy under general anaesthesia. If the ectopic pregnancy cannot be removed laparoscopically, a laparotomy is performed. This is known as traditional open surgery and requires making a large surgical incision in the abdominal cavity.

Patients whose fallopian tube has been removed can still get pregnant as long as they have one remaining healthy fallopian tube. However, their future fertility can still be affected by their own risk factors including smoking and using assisted reproductive technology to get pregnant.

References:

  • Kirk E, Bottomley C, Bourne T (2014). "Diagnosing ectopic pregnancy and current concepts in the management of pregnancy of unknown location". Human Reproduction Update. 20 (2): 250–61.

  • Zhang J, Li F, Sheng Q (2008). "Full-term abdominal pregnancy: a case report and review of the literature". Gynecologic and Obstetric Investigation. 65 (2): 139–41.

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