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 
- Heterotopic pregnancy: a rare condition involving multiple gestations, in which one is intrauterine and another is ectopic. Occurs more frequently in patients undergoing infertility treatments, e.g., in vitro fertilization. 
- Fallopian tube (∼ 95% of cases)
- Ovary (∼ 3% )
- Abdomen (∼ 1%)
- Cervix (< 1%)
Risk factors for ectopic pregnancy 
Anatomic alteration of the fallopian tubes
- History of (e.g., salpingitis)
- Previous ectopic pregnancy
- Surgeries involving the fallopian tubes (e.g. tubectomy)
- 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
The following recommendations are consistent with the 2018 American College of Obstetricians and Gynecologists (ACOG) Practice Bulletin on tubal ectopic pregnancy and the 2017 American College of Emergency Physicians (ACEP) Clinical Policy on the initial evaluation and management of patients with early pregnancy presenting to the emergency department. 
Hemodynamically unstable patients
- Start acute stabilization measures (see “Management of ruptured ectopic pregnancy”).
- If trained, perform a point-of-care ultrasound (see “POCUS in early pregnancy” and “FAST”) to identify intraperitoneal free fluid or confirm intrauterine pregnancy (IUP).
- If IUP is confirmed, evaluate for alternate causes of hemodynamic instability (see “Shock”).
- If any of the following are present, refer for immediate surgical exploration without awaiting further diagnostic studies:
- Urgently consult OB/GYN for surgical exploration based on clinical suspicion supplemented by POCUS findings (if performed).
- Obtain a transvaginal ultrasound) as soon as the patient is stable enough. (
- Stable patients: Send serum β-hCG and arrange or perform a pelvic ultrasound (e.g., or formal ultrasound) regardless of β-hCG level. 
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 IUP is typically visible on ultrasound 
Serial β-hCG measurements (every 48 hours)
- Better diagnostic accuracy than a single β-hCG level in differentiating intrauterine from ectopic pregnancies
- Findings after 48 hours
The expected percentage increase in β-hCG for normal IUPs is determined based on the initial level. 
- Initial level < 1500 mIU/mL: > 49% expected increase
- Initial level 1500–3000 mIU/mL: > 40% expected increase
- Initial level > 3000 mIU/mL: > 33% expected increase
- Falling β-hCG levels may indicate a failed IUP (e.g., spontaneous abortion) or an ectopic pregnancy.
- An insufficient decline in serial β-hCG measurements following induced abortion should raise suspicion for ectopic pregnancy (for more information, see “”).
- The expected percentage increase in β-hCG for normal IUPs is determined based on the initial level. 
- 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
Can be performed as aor . 
- 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
- POCUS can be performed using the transabdominal approach to rapidly rule in IUP if present.
Endometrial biopsy 
- Indication: Consider only in cases of pregnancy of unknown location where nonviability is certain.
- Findings 
- See “.”
- See “.”
The differential diagnoses listed here are not exhaustive.
- Unstable patients: See “Management of ruptured ectopic pregnancy.”
Stable patients: Determine whether medical, surgical, or expectant management is appropriate.
- Consider clinical, laboratory, and radiological findings.
- Share decision-making with patients in consultation with OB/GYN.
- All patients: Provide adequate supportive care.
- Patients suited to medical or expectant management at home
Provide for all patients regardless of management approach.
- Pain management
- Prenatal and contraceptive counseling once treatment is complete 
- Anti-D immunoglobulin for Rh-negative patients who present with bleeding
Medical therapy (methotrexate) 
- Mechanism of action: inhibits folate-dependent steps in DNA synthesis to terminate the rapidly dividing ectopic pregnancy.
- Indications 
- Chronic conditions
- Intrauterine pregnancy
- 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 “Adverse effects of immunosuppressants.”
- Patients should avoid the following during MTX therapy:
Nonurgent surgical management 
See “Management of ruptured ectopic pregnancy” for emergency surgical indications and preferred approach.
Indications for nonurgent surgery
- 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.
- Approach Laparoscopy (preferred)
Procedure: salpingostomy, i.e., removal of ectopic pregnancy without removing the affected fallopian tube (tube‑conserving operation)
- Preferred in patients with unruptured tubal pregnancy who do not meet the criteria for conservative treatment
- Additional considerations
- ectopic mass). may be required in select cases (e.g., large
Asymptomatic patients with very low β-hCG levels may experience spontaneous resolution of ectopic pregnancy without medical or surgical treatment. Consider this approach in select patients after consultation with OB/GYN. 
Considerations during expectant management
- Provide extensive counseling on the risks of complications in addition to general counseling (see “Approach”).
- Arrange close surveillance and serial β-hCG measurement (e.g., every 2–7 days).
- Conversion to medical or surgical therapy
Follow thefor patients with obvious signs of rupture and those at high risk of impending rupture.
- Clinical features of shock: e.g., tachycardia, hypotension, pallor
- Severe abdominal or pelvic pain
- Peritoneal signs on examination
- Significant vaginal bleeding
- POCUS positive for intraperitoneal free fluid
- Clinical deterioration after receiving MTX therapy 
- Obtain IV access; send an urgent and crossmatch.
- Start immediate .
- Rapidly deliver blood transfusion as soon as blood products are available.
- Activate protocol if necessary.
- Consider tranexamic acid for persistently unstable patients in consultation with OBGYN. 
- If hypotension persists, start vasopressors (see “Shock”).
- Consider interventional radiology referral for angioembolization in consultation with OB/GYN.
- Indications for emergency surgery
- Approach: Laparotomy is preferred for large intraperitoneal bleeding or critically unstable patients, otherwise a laparoscopic approach is typically performed.
Procedure: salpingectomy, i.e., partial or complete removal of the affected fallopian tube (does not preserve tube function)
- Preferred approach for:
- Additional considerations
- 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 line
- Start IV fluid resuscitation.
- Check CBC, type and screen, and prepare for blood transfusion.
- Urgent OB/GYN consult for emergency salpingectomy
- Provide as needed.
- For patients with hemorrhagic shock, start transfusion as soon as blood products are available and consider massive transfusion protocol.
- Parenteral analgesics: Opioids are preferred.
- Continuous telemetry and frequent blood pressure checks
- Transfer to OR.