Ectopic pregnancy occurs when an embryo attaches outside the uterus, most commonly in the fallopian tubes. It is frequently associated with pelvic inflammatory disease (PID), which may lead to stenosis of the fallopian tubes. This prevents the fertilized egg from passing through to the uterus, instead causing it to attach to the tube itself. In addition to signs of pregnancy, symptoms include abdominal pain and vaginal bleeding. The first diagnostic step is to confirm the pregnancy with a β-hCG test, which should be followed by a transvaginal ultrasound to determine the location of the pregnancy and the fetal heartbeat. Uncomplicated ectopic pregnancies often resolve spontaneously and are usually difficult to diagnose. Patients are typically hemodynamically stable with low, declining hCG concentrations (< 5000 IU/L). Complicated cases may involve tubal abortion or rupture, which can lead to intraabdominal bleeding and shock. Whereas uncomplicated cases are treated conservatively (e.g., methotrexate or expectant management), complicated ectopic pregnancy requires surgical removal. In cases of abdominal pain in women of reproductive age, it is therefore important to rule out ruptured ectopic pregnancy.
- Ectopic pregnancy: a pregnancy in which the fertilized egg attaches in a location other than the uterine endometrium
- Tubal pregnancy: a pregnancy that occurs within the fallopian tube 
- Interstitial pregnancy: a pregnancy that occurs within the interstitial portion of the fallopian tube (i.e., the segment that connects the tube to the endometrial cavity)
- Complicated ectopic pregnancy 
- Uncomplicated ectopic pregnancy 
- Fallopian tube (∼ 95% of cases)
- Ovary (∼ 3% )
- Abdomen (∼ 1%)
- Cervix (< 1%)
Risk factors 
Anatomic alteration of the fallopian tubes
- History of (e.g., salpingitis)
- Previous ectopic pregnancy
- Surgeries involving the fallopian tubes
- Ruptured appendix
- Kartagener syndrome
- Exposure to diethylstilbestrol (DES) in utero 
- Bicornuate uterus
Nonanatomical risk factors
General symptoms 
- Patients usually present with signs and symptoms 4–6 weeks after their last menstrual period.
- Lower abdominal pain and guarding (ectopic pregnancy is often mistaken for appendicitis due to the similarity of symptoms)
- Possibly, vaginal bleeding
- Signs of pregnancy
- Tenderness in the area of the ectopic pregnancy
- Cervical motion tenderness, closed cervix
- Enlarged uterus
- Interstitial pregnancies tend to present late, at 7–12 weeks of gestation, because of myometrial distensibility.
Tubal rupture 
- Acute course with sudden and severe lower abdominal pain (acute abdomen)
Signs of hemorrhagic shock (e.g., tachycardia, hypotension, syncope) 
- In some cases acute hemorrhage may lead to bradycardia.
- The exact mechanism behind this phenomenon is not yet fully understood.
- More common in interstitial pregnancy
- Consider ectopic pregnancy in all women of childbearing age presenting with general symptoms of ectopic pregnancy or with known risk factors (e.g., anatomic alteration of the fallopian tubes).
- If the patient is hemodynamically unstable, provide hemodynamic support and consider immediate surgical exploration.
- The diagnosis is confirmed with transvaginal ultrasound (TVUS).
Laboratory studies 
Serum β-hCG level
- Finding: ↑ β-hCG
- Increased β-hCG is verifiable from the eighth day after ovulation.
- β-hCG discriminatory level: the β-hCG level at which an intrauterine pregnancy should be visible on ultrasound.
Serial β-hCG measurements
- Better diagnostic accuracy than a single β-hCG level in differentiating intrauterine from ectopic pregnancies
- Frequency of measurements: every 48 hours
- Findings after 48 hours
- CBC: Anemia may be seen in patients with vaginal bleeding.
- Blood type and screen: ABO and Rh testing to identify patients who might need Rho immunization
- LFT, BMP: to determine baseline liver and renal function
Transvaginal ultrasound (TVUS)
- Indication: best initial imaging test for determining the location of the pregnancy
- Empty uterine cavity in combination with a thickened endometrial lining
- Possible free fluid within the pouch of Douglas (unspecific)
- Additional findings in tubal pregnancy
- Additional findings in interstitial pregnancy
- Additional considerations
Transabdominal ultrasound (TAUS)
- Can be used to exclude differential diagnoses (e.g., acute appendicitis)
- Provides a general picture of the pelvic anatomy and upper abdomen but is less sensitive than TVUS in detecting extrauterine pregnancy
Endometrial biopsy 
- Indication: Consider only in cases of pregnancy of unknown location where nonviability is certain.
- Findings 
See also “.”
Painful vaginal bleeding
|Overview of differential diagnoses of painful vaginal bleeding |
|Differential diagnosis||Description of pain||Characteristics|
|Benign neoplasms|| || |
| || |
|Ovarian cyst rupture|| || |
| Trauma |
(e.g., foreign body, sexual abuse)
Painless vaginal bleeding
|Overview of differential diagnoses of painless vaginal bleeding |
| Iatrogenic |
(e.g., anticoagulants, , )
Anembryonic pregnancy 
The differential diagnoses listed here are not exhaustive.
In hemodynamically unstable patients with ruptured or impending rupture of ectopic pregnancy, emergency surgery is indicated. In all other patients, the decision for medical, expectant, or surgical treatment of ectopic pregnancy should be guided by the clinical, laboratory, and radiological findings as well as patient-informed choice based on a discussion of the benefits and risks of each approach.
Medical treatment 
- Mechanism of action: inhibits folate-dependent steps in DNA synthesis to terminate the rapidly dividing ectopic pregnancy.
- Indications 
- Chronic conditions
- Methotrexate sensitivity
- Peptic ulcer disease
- Ruptured ectopic pregnancy
|Methotrexate regimens for medical treatment of ectopic pregnancy |
|Single-dose regimen||Two-dose regimen||Multiple-dose regimen|
|Characteristics|| || || |
|Methotrexate administration|| |
|Response to β-hCG monitoring results|
- Adverse effects: See “Side effects” in immunosuppressants.
- Patients should avoid the following during MTX therapy:
- Supportive care: analgesics
- Prenatal counseling once treatment is complete
- Anti-D immunoglobulin for Rh-negative patients who present with bleeding
Surgical treatment 
- Hemodynamic instability
- Symptoms of impending rupture (e.g., pelvic pain)
- Signs of intraperitoneal bleeding
- Risk factors for rupture 
- Contraindications for MTX
- Unsuccessful medical treatment
- A concurrent surgical procedure (e.g., bilateral tubal blockage) is necessary.
- The patient has indicated a preference for surgical treatment.
Salpingostomy (tube‑conserving operation)
- Indication: patients with unruptured tubal pregnancy who do not meet the criteria for conservative treatment
- Procedure: removal of ectopic pregnancy without removing the affected fallopian tube
- Additional considerations
Salpingectomy (does not preserve tube function)
- Preferred approach for:
- Procedure: partial or complete removal of the affected fallopian tube
- Additional considerations
Considerations during expectant management
- Patients should receive extensive counseling on the risks of complications.
- Close surveillance is mandatory.
- β-hCG should be obtained every 48 hours until a decrease is confirmed, then weekly until negative.
Conversion to medical or surgical therapy
- Increasing symptoms
- β-hCG levels increase or plateau
- OB/GYN consult for consideration of medical treatment, surgical treatment, or expectant management
- Close monitoring
- Laboratory studies (CBC, type and screen)
- Analgesics (see pain management)
- IV access with two large-bore peripheral IV lines
- Urgent OB/GYN consult for emergency salpingostomy
- Provide hemodynamic support as needed.
- Check CBC, type and screen, and prepare for blood transfusion.
- Parenteral analgesics: Opioids are preferred.
- Continuous telemetry and frequent blood pressure checks
- Transfer to OR.