Ectopic Pregnancy on US (Case courtesy of A.Prof Frank Gaillard, From the case rID: 8161)

Definition: Embryo implantation outside of the endometrial cavity

Background: (Alkatout 2013)

  • Ectopic pregnancy occurs in up to 2% of pregnancies.
  • It is the leading cause of 1st trimester death and causes 0.5 deaths/100,000 live births.
  • Ectopic Location (Arleo 2014)
    • Greater than 95% of extrauterine implantations occur in the fallopian tube.
    • Interstitial pregnancies: occur in to the most proximal segment of the fallopian tube within the uterine wall
    • Cornual pregnancies occur in the upper and lateral portion of the uterus.
    • Rare cervical pregnancies implant in the uterine endocervix. They may be confused with an aborting intrauterine pregnancy (IUP) residing in the cervix and may lead to massive hemorrhage if disturbed.
  • Heterotopic pregnancy: An ectopic pregnancy in conjunction with an IUP
    • Natural conception rate: 1/30,000
    • Assisted reproduction rate: 1/100
  • Ectopic pregnancy rupture is often associated with profound hemorrhage, which may be fatal if rapid surgical intervention isn’t undertaken
  • The vast majority of deaths occur prior to hospitalization or just after to arrival to the emergency department. (Anderson 2004)

Clinical Presentation:

  • Classic Triad
    • Abdominal pain
    • Vaginal bleeding
    • Missed menstrual period
  • Patient’s typically present 6-8 weeks after the last normal menstrual period
  • Signs and symptoms suggestive of rupture
    • Vital sign abnormalities
      • Hypotension
      • Tachycardia
      • Shock
    • Lightheadedness/syncope
    • Cool, pale skin
    • Nausea + emesis
    • Severe abdominal pain
  • Referred pain
    • Diaphragmatic irritation from free blood in the peritoneal space may present as shoulder pain
    • Referred neck or rectal pain are reported
  • Vagal stimulation from intra-peritoneal blood can present as hypotension and bradycardia

Selected Differential Considerations:

  • OB/GYN conditions: Spontaneous abortion (of normal IUP), septic abortion, early normal IUP, ovarian cyst, ovarian/fallopian torsion, necrotic myoma, PID/TOA
  • Others: Appendicitis, cystitis, obstructed viscus, perforated viscus, pyelonephritis, vascular hemorrhage/ischemia.

Free Fluid in Morrison’s Pouch (AHC Media)

Evaluation of Unstable Patients

  • Rapid identification is paramount
    • Ruptured ectopic should be considered in any hemodynamically unstable woman of child bearing age
    • Presence of free fluid in absence of trauma in this group should be considered ectopic pregnancy until proven otherwise
  • Basic Management
    • ABCs, Large bore (> 18 gauge) IV X 2, Supplemental O2 if necessary
    • Approach similar to exsanguinating trauma patient
  • Key actions:
    • Perform a FAST exam
      • Positive result requires immediate OB/Gyn or surgical consultation for surgical exploration
      • Can improve sensitivity by placing patient in Trendelenburg position
    • Hemodynamic instability should trigger massive transfusion protocol
    • Start resuscitation with O negative blood (start with crystalloid resuscitation if blood not immediately available)

Ectopic Pregnancy US (Case courtesy of Dr Maulik S Patel, From the case rID: 46956)

Evaluation of Stable Patients

  • Rapid, unexpected decompensation can occur
  • Pertinent History/Risk Factors: prior genital tract infection(s), prior ectopic pregnancy, prior dilatation and curettage or tubal ligation, current IUD, assisted reproduction, age >35, tobacco use, progestin-only contraception
  • Assessment
    • Vital signs: may be normal early in the course of significant bleeding, particularly in young patients due to compensatory mechanisms
    • Physical examination: lower abdominal tenderness or diffuse tenderness with or without rebound or guarding, depending on extent of hemorrhage
    • FAST exam (for free fluid)
  • Laboratory evaluation
    • Quantitative pregnancy test
    • CBC (to aid in assessment of blood loss)
    • Basic metabolic panel (renal function important consideration in medical management)
    • Type and screen (with Rh factor status)
    • PT/PTT and fibrinogen in unstable patients (assessment for DIC)
  • Imaging
    • Transabdominal US can rapidly identify IUP but can miss early pregnancy
    • Transvaginal US (TVUS) is more sensitive for diagnosing an IUP and for finding an ectopic
  • Heterotopic Pregnancy (Ultrasound Image Gallery)

    Management based on imaging

    • Ultrasound with (+) IUP
      • Ectopic highly unlikely (possible in heterotopic)
      • Manage as threatened Ab
      • Consider hetertopic pregnancy in patients with assisted reproduction
    • Ultrasound with (+) ectopic
      • OB/Gyn consultation for further management
    • Ultrasound with no IUP or ectopic (indeterminate US) AND no free fluid
      • β-hCG level < 1500 (Condous 2005)
        • May be early IUP
        • Typically will get repeat β-hCG in 48 hours to look for appropriate rise and repeat US
      • β-hCG level > 1500
        • Risk of ectopic rises as TVUS usually locates IUP above this level
        • Management will be based on shared decision making with patient and OB/Gyn
          • Medical abortion (methotrexate)
          • Expectant management (repeat US and β-hCG)
  • Medical management with methotrexate
    • Eligible Patients:
      • Hemodynamically Stable,
      • Hcg <5000,
      • Need to comply with treatment and follow up,
      • No fetal cardiac activity
    • Contraindications:
      • Renal insufficiency
      • Immunodeficiency
      • Active Pulmonary Disease
      • Peptic Ulcer Disease
      • Hypersenstivity to MTX
      • Heterotopic Pregnancy with viable IUP
      • Breastfeeding
    • Dosing
    • Disposition
      • Patients with ectopic pregnancy may be discharged after administration of methotrexate
      • Indeterminate US
        • Hemodynamically stable patients may be discharged
        • Close follow up is mandatory

Take Home Points

  • Ecoptic pregnancy is the leading cause of 1st trimester maternal death
  • Always consider the diagnosis of an ectopic pregnancy in any woman of child bearing age presenting with abdominal pain, vaginal bleeding, and missed period
  • Hemodynamically unstable patients need rapid diagnosis and stabilizing treatment
  • Involve consulting services early on in management course


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