This leaflet is to help you understand what Abdominal Ectopic Pregnancy is, what tests you need and the implication of being diagnosed are for you, your baby and your family.

What is an abdominal ectopic pregnancy?

An ectopic pregnancy occurs when a fertilised egg implants and grows outside the main cavity of the uterus. The majority (>95%) of ectopic pregnancies are located in the Fallopian tube, 3-5% are in rarer sites (interstitial, cornual, Caesarean section scar, cervical, ovarian, or abdominal implantation). Abdominal pregnancy is an extremely rare type of ectopic pregnancy where the developing embryo implants and grows within the abdominal cavity. 

How does an abdominal ectopic pregnancy happen?

Under normal physiologic conditions, a fertilized egg migrates from the fallopian tube to implant into the womb. If it fails to reach its normal position within the endometrial cavity, an ectopic pregnancy occurs. 

There have been several theories to explain how an abdominal pregnancy occurs.  The fertilization may occur posterior to the uterus where sperm is known to accumulate, and an egg might be found there as a result of the dependent flow of peritoneal fluid. Others hypothesized that the abdominal pregnancy would occur because of migration of the embryo from the female reproductive tract to the peritoneal cavity by travelling along lymphatic channels.

What are the symptoms of an abdominal pregnancy?

The clinical presentation is variable. Symptoms are not specific and may overlap with those of other ectopic pregnancies. You may not notice any symptoms at all. Possible symptoms include:

  • Amenorrhoea (absence of menstrual period) is common. In some cases, abnormal bleeding is mistaken as a menstrual period so Amenorrhoea goes unnoticed.
  • Abdominal pain is one of the most consistent findings and the localizing pain may be related to the site of pregnancy. In advanced abdominal pregnancy, pain during fetal movements, or palpation of fetal parts under the abdominal wall have been reported.
  • Vaginal bleeding is a common presentation. The bleeding is often light but can be prolonged and intermittent.
  • Some women may present with gastrointestinal symptoms (e.g. nausea and vomiting), so the suspected clinical diagnosis might be gastroenteritis rather than ectopic pregnancy. 

How is an abdominal ectopic pregnancy diagnosed?

A pelvic exam can help your doctor identify areas of pain, tenderness, or a pelvic mass but cannot definitively diagnose an ectopic pregnancy. If you take a pregnancy test and the result is positive, it means that you are pregnant but it does not help to localize the position of pregnancy, in the uterus or outside the uterus.  

Your doctor may ask you to have a blood test (called human chorionic gonadotropin or ß-hCG) to confirm that you are pregnant. Levels of this hormone increase during pregnancy. A suboptimal rise in this pregnancy hormone over a few days can suggest the diagnosis of an ectopic pregnancy but does not help to confirm the diagnosis of an abdominal pregnancy. Sometimes, this blood test may be repeated every few days until ultrasound testing can confirm or rule out an ectopic pregnancy.

Transvaginal ultrasound scan (TVS) is the tool of choice for diagnosis of ectopic pregnancy. With this type of ultrasound, a device called a transducer is placed in your vagina. A transvaginal ultrasound allows your doctor to see the exact location of your pregnancy. When transvaginal ultrasound examination cannot determine a pregnancy, a thorough transabdominal ultrasound examination must be done to look for the rarer locations. If the location of the pregnancy is still uncertain, a MRI scan can help to confirm the diagnosis of an abdominal pregnancy.

What are the things to watch for?

An abdominal ectopic pregnancy cannot proceed normally. If left untreated, the fertilized egg continues to grow and may rupture and cause life-threatening bleeding.  Symptoms of this life-threatening complication include severe abdominal or pelvic pain, fainting and shock. It is therefore important that if you experience severe pain or any other worrying symptoms that you should go to the nearest emergency department immediately.

What are the treatment options?

A fertilized egg cannot develop normally outside the uterus. To prevent life-threatening complications, the abdominal ectopic pregnancy needs to be removed or ceased. Depending on your symptoms and when the abdominal ectopic pregnancy is diagnosed, your doctor may recommend medical treatment with drugs, laparoscopic surgery (“keyhole” surgery, or “closed” surgery) or abdominal surgery (open surgery). Medication is less invasive than surgery, but it requires serial follow-up of hCG levels in your blood, and ultrasound scans.

What are the risk factors?

Risk factors for abdominal pregnancy are similar to risks described for other ectopic pregnancies: previous ectopic pregnancy, tubal surgeries/rupture, endometriosis, and pelvic inflammatory disease. No specific risk factors are particularly associated with abdominal ectopic pregnancy.

Will it happen again?

There is no way to prevent an abdominal ectopic pregnancy, but here are some ways to decrease the risk of its happening again: preventing sexually transmitted infections may reduce the risk of pelvic inflammatory disease which is a risk factor for ectopic pregnancy; stopping smoking if you are trying to get pregnant may also decrease your risk of ectopic pregnancy.

What other questions should I ask? 

  • When is my next follow-up appointment?
  • What are my chances of having a healthy pregnancy in the future?
  • How long should I wait before trying to become pregnant again?
  • Will I need to follow any special precautions if I become pregnant again?
  • Is there a number I can contact if I have any further questions?

Last updated: July 2022