Ectopic Pregnancy

An ectopic pregnancy is one that occurs outside of the uterus, usually in the Fallopian tubes.  It is considered a medical emergency requiring hospital admission.

97% of ectopic pregnancies occur in the Fallopian tubes.

Incidence; Contributing Risk Factors

Ectopic pregnancies make up approximately 1% of pregnancies.

Factors that increase the risk of having an ectopic pregnancy include:

• assisted reproductive techniques
• a history of ectopic pregnancy
• having undergone a reversal of sterilization
• inflammation caused by endometriosis
• previous pelvic inflammatory disease
• adhesions resulting from infection
• using an IUD for contraception (Note also: if an IUD fails, the risk of ectopic pregnancy is around 50%)
• using a progestogen-only contraceptive which then fails

Signs and Symptoms

Aside from those mentioned below, other symptoms of ectopic pregnancy include:

• urinary symptoms
• passage of tissue through the vagina
• rectal pain or pressure during defecation
• pelvic or abdominal tenderness
• adnexal tenderness
• enlarged uterus
• rebound tenderness
• cervical tenderness
• pallor
• abdominal distension
• tachycardia and/or hypotension (related to hypovolemia)
• shock or collapse

Diagnosis and Tests

When an ectopic pregnancy is present, the signs are not always obvious.  It should always be considered as a possibility in women of reproductive age.

A differential diagnosis should consider 'threatened miscarriage' and ectopic pregnancy.  In the former, vaginal bleeding is the main symptom and pain may come later as the cervix dilates.  In ectopic pregnancies, the pain usually comes first and vaginal bleeding is less significant – and sometimes absent.

Human chorionic gonadotrophin (hCG) levels are often tested.  Conservative management may be appropriate if the levels of hCG are falling and the patient is clinically well.

Note: Due to increased risk of rupture of an ectopic pregnancy following palpation, internal examination should normally be avoided if ectopic pregnancy is suspected.  The safest and most accurate method for detecting an ectopic pregnancy is transvaginal ultrasound: it can identify the location of the pregnancy and even detect any fetal heartbeat.

Treatment and Prevention

Single-dose methotrexate treatment appears to be as effective as surgery.  It can be used in cases where there is no significant pain, the ectopic pregnancy has not ruptured, the adnexal mass is < 35mm in size, there is no detectable fetal heartbeat, no normal (intrauterine) pregnancy can be seen on an ultrasound scan, and serum hCG < 1500 IU/L. A repeat injection may be required, and there are some side-effects to be aware of.

In other cases, laparoscopic surgery is generally used.

Prognosis; Complications; Seek medical attention if...

When detected sufficiently early, prognosis is excellent.  Most women are now diagnosed before tubal rupture, which results in a much improved outcome – including tubal preservation and the potential for future fertility.

In the West, only about 1-in-500 cases of ectopic pregnancy result in maternal death, with most of these being the result of substandard care.

Following an ectopic pregnancy, the risk of another ectopic pregnancy is about 10-20% and the chance of a successful intrauterine pregnancy is about 70%.

If left untreated, an ectopic pregnancy can be life-threatening: tubal or uterine rupture can lead to massive hemorrhage, shock, disseminated intravascular coagulopathy (DIC), and possible death.

Common surgical complications are also a possibility.

Women with a confirmed pregnancy should seek immediate medical attention if any of the following symptoms are present:

• abdominal pain and/or tenderness
• pelvic tenderness
• 'cervical excitation' found during pelvic examination
• vaginal bleeding