Ectopic pregnancy

Changed by Matt A. Morgan, 31 Dec 2014

Updates to Article Attributes

Body was changed:

Ectopic pregnancy refers to the implantation of a fertilised ovum outside of the uterine cavity. 

Epidemiology

The overall incidence has increased over the last few decades and is currently thought to affect 1-2% of pregnancies. There is an increased incidence in in-vitro fertilisation pregnancies (IVF).

Clinical presentation

Presentation is often with abdominal pain or bleeding. If unrecognised haemorrhage can be life threatening.

Pathology

Location of ectopics
Markers
  • serum beta HCG levels tend to increase at a slower rate
  • serum progesterone levels can be not as elevated as for an intrauterine pregnancy 6; 5-25 ng/ml range although not absolute reference required

Radiographic features

It is essentialuseful to know a quantitative beta HCG prior to scanning as this will determineguide what you expect to see. At levels below 1000 IU a normal early pregnancy may well not be visible, and therefore should the scan prove negative, a repeat scan in a couple of days (along with a repeat beta HCG) is necessary (beta HCG should normally double approximately every two days during the first 8 weeks).

Ultrasound

The ultrasound exam should be performed both transabdominally and transvaginally. The transabdominal component provides a wider view of the abdomen to assess for potential free fluid.

Positive findings in a beta HCG positive (over 1000(>1000 IU) patient include:

  • uterus
    • empty uterine cavity/no / no evidence of intra-uterine pregnancy
    • pseudogestational sac/decidual cyst: may be seen in 10-20% of ectopic pregnancies
      • current evidence suggests that one should not initiate treatment for an ectopic pregnancy in a hemodynamically stable woman on the basis of a single hCG value 10.
    • decidual cast
  • tube and ovary
    • simple adnexal cyst: 10% chance of an ectopic
    • complex adnexalextra-adnexal cyst/mass: 95% chance of an tubal ectopic (if no IUP)
      • an intra-adnexal cyst/mass is more likely to be a corpus luteum
    • tubal ring sign
      • 95% chance of an tubal ectopic if seen
      • described in 49% of ectopics and in 68% of unruptured ectopics
    • ring of fire sign: can be seen on colour Doppler in a tubal ectopic
    • live pregnancy: 100% specific, but only seen in a minority of cases
  • peritoneal cavity
    • free pelvic fluid/haemoperitoneum in the pouch of Douglas
      • the presence of free intra peritonealintraperitoneal fluid in the context of a positive beta HCG and empty uterus is
        • ~70% specific for an ectopic pregnancy 4
        • ~63% sensitive for an ectopic pregnancy 4
    • live pregnancy: 100% specific, but only seen in a minority of cases.

ItIn patient receiving in vitro fertilization (IVF), it is of utmost importance important not to be completely reassured by the presence of a live intrauterine pregnancy8, as this may delay the important diagnosisthere is a possibility of a co-existing ectopic pregnancy in ~1:500 (i.e. heterotopic pregnancy). This life-threatening condition for both mother and intrauterine child necessitates a high levelIn patients not receiving IVF, the risk of clinical suspicion, especially in cases of assisted reproduction (e.g. in-vitro fertilisationheterotopic pregnancy is miniscule (1:30,000) or former tubal surgery 8. 

Diagnostic work up

For an imaging pathway on how to work up a suspected ectopic pregnancy in terms of choice of imaging modality: see reference 9

Complications

Complications somewhat depend on the type of ectopic. General complications for a typical (tubal) ectopic pregnancy include

Management

No single strategy can be employed as preferred management depends on the location of the ectopic pregnancy. In general, the options are:

  • surgical: (in the case of tubal ectopics with open or laparoscopic salpingectomy or salpingotomy)
  • medical
    • methotrextate (a folate antagonist) either administered systemically or by direct ultrasound guided injection or potassium chloride (direct injection only obviously)
    • usually considered if size small (e.g <4 cm) and if no concurrent complication
    • the gestational mass can paradoxically increase in size following methotrexate on subsequent scanning and does not necessarily imply failure of methotrexate therapy 3
  • conservative or expectant management is being recognised as an option for those ectopics where rupture has not occurred (i.e. no haemoperitoneum) and fetal demise has already taken place

Differential diagnosis

The differential diagnosis of abdominal pain in a pregnant patient is broad. An ectopic pregnancy must be excluded with ultrasound. Other common diagnoses in this setting include:

In a clinically suspected ectopic pregnancy that is not confirmed on ultrasound, the differential is frequently that of a pregnancy of unknown location, with the alternative possibilities being of a very early pregnancy or a completed miscarriage.

  • -<li>serum beta HCG levels tend to increase at a slower rate</li>
  • +<li>serum <a href="/articles/beta-hcg-levels">beta HCG levels</a> tend to increase at a slower rate</li>
  • -</ul><h4>Radiographic features</h4><p>It is essential to know a quantitative <a href="/articles/beta-hcg">beta HCG</a> prior to scanning as this will determine what you expect to see. At levels below 1000 IU a normal <a href="/articles/early-pregnancy">early pregnancy</a> may well not be visible, and therefore should the scan prove negative, a repeat scan in a couple of days (along with a repeat beta HCG) is necessary (beta HCG should normally double approximately every two days).</p><h5>Ultrasound</h5><p>Positive findings in a beta HCG positive (over 1000 IU) patient include:</p><ul>
  • +</ul><h4>Radiographic features</h4><p>It is useful to know a quantitative <a href="/articles/beta-hcg-levels">beta HCG</a> prior to scanning as this will guide what you expect to see. At levels below 1000 IU a normal <a href="/articles/early-pregnancy">early pregnancy</a> may well not be visible, and therefore should the scan prove negative, a repeat scan in a couple of days (along with a repeat beta HCG) is necessary (beta HCG should normally double approximately every two days during the first 8 weeks).</p><h5>Ultrasound</h5><p>The ultrasound exam should be performed both transabdominally and transvaginally. The transabdominal component provides a wider view of the abdomen to assess for potential free fluid.</p><p>Positive findings in a beta HCG positive (&gt;1000 IU) patient include:</p><ul>
  • -<li>empty uterine cavity/no evidence of intra-uterine pregnancy</li>
  • +<li>empty uterine cavity / no evidence of intra-uterine pregnancy</li>
  • -<a href="/articles/pseudo-gestational-sac">pseudogestational sac</a>/<a href="/articles/decidual-cyst">decidual cyst</a>: may be seen in 10-20% of ectopic pregnancies</li>
  • +<a href="/articles/pseudogestational-sac-1">pseudogestational sac</a> / <a href="/articles/decidual-cyst">decidual cyst</a>: may be seen in 10-20% of ectopic pregnancies<ul><li>current evidence suggests that one should not initiate treatment for an ectopic pregnancy in a hemodynamically stable woman on the basis of a single hCG value <sup>10</sup>.</li></ul>
  • +</li>
  • -<li>complex adnexal cyst/mass: 95% chance of an tubal ectopic</li>
  • +<li>complex extra-adnexal cyst/mass: 95% chance of an tubal ectopic (if no IUP)<ul><li>an intra-adnexal cyst/mass is more likely to be a <a href="/articles/corpus-luteum">corpus luteum</a>
  • +</li></ul>
  • +</li>
  • -<li>free pelvic fluid/<a href="/articles/haemoperitoneum">haemoperitoneum </a>in the <a href="/articles/pouch-of-douglas">pouch of Douglas</a><ul><li>the presence of free intra peritoneal fluid in the context of a positive beta HCG and empty uterus is<ul>
  • +<li>free pelvic fluid / <a href="/articles/haemoperitoneum">haemoperitoneum </a>in the <a href="/articles/pouch-of-douglas">pouch of Douglas</a><ul><li>the presence of free intraperitoneal fluid in the context of a positive beta HCG and empty uterus is<ul>
  • -</ul><p>It is of utmost importance not to be reassured by the presence of a live intrauterine pregnancy, as this may delay the important diagnosis of a co-existing ectopic pregnancy (i.e. <a href="/articles/heterotopic-pregnancy">heterotopic pregnancy</a>). This life-threatening condition for both mother and intrauterine child necessitates a high level of clinical suspicion, especially in cases of assisted reproduction (e.g. in-vitro fertilisation) or former tubal surgery <sup>8</sup>. </p><h5>Diagnostic work up</h5><p>For an imaging pathway on how to work up a suspected ectopic pregnancy in terms of choice of imaging modality: see <strong>reference 9</strong></p><h4>Complications</h4><p>Complications somewhat depend on the type of ectopic. General complications for a typical (tubal) ectopic pregnancy include</p><ul><li>
  • -<a href="/articles/tubal-rupture">tubal rupture</a>: 15-20% </li></ul><h4>Management</h4><p>No single strategy can be employed as preferred management depends on the location of the ectopic. In general the options are:</p><ul>
  • +</ul><p>In patient receiving in vitro fertilization (IVF), it is important not to be completely reassured by the presence of a live intrauterine pregnancy <sup>8</sup>, as there is a possibility of a co-existing ectopic pregnancy in ~1:500 (i.e. <a href="/articles/heterotopic-pregnancy">heterotopic pregnancy</a>). In patients not receiving IVF, the risk of heterotopic pregnancy is miniscule (1:30,000) </p><h5>Diagnostic work up</h5><p>For an imaging pathway on how to work up a suspected ectopic pregnancy in terms of choice of imaging modality: see <strong>reference 9</strong></p><h4>Complications</h4><p>Complications somewhat depend on the type of ectopic. General complications for a typical (tubal) ectopic pregnancy include</p><ul><li>
  • +<a href="/articles/tubal-rupture">tubal rupture</a>: 15-20% </li></ul><h4>Management</h4><p>No single strategy can be employed as preferred management depends on the location of the ectopic pregnancy. In general, the options are:</p><ul>
  • -<li>usually considered if size small (e.g &lt;<strong>4</strong> cm) and if no complication</li>
  • +<li>usually considered if size small (e.g &lt;<strong>4</strong> cm) and if no concurrent complication</li>
  • -<li>conservative or expectant management is being recognised as an option for those ectopics where rupture has not occurred (i.e. no <a href="/articles/haemoperitoneum">haemoperitoneum</a> ) and fetal demise has already taken place</li>
  • +<li>conservative or expectant management is being recognised as an option for those ectopics where rupture has not occurred (i.e. no <a href="/articles/haemoperitoneum">haemoperitoneum</a>) and fetal demise has already taken place</li>
  • -<li><a href="/articles/appendicitis">appendicitis</a></li>
  • +<li>
  • +<a href="/articles/appendicitis">appendicitis</a> (negative beta hCG)</li>

References changed:

  • 9. Doubilet P & Benson C. Further Evidence Against the Reliability of the Human Chorionic Gonadotropin Discriminatory Level. J Ultrasound Med. 2011;30(12):1637-42. <a href="https://doi.org/10.7863/jum.2011.30.12.1637">doi:10.7863/jum.2011.30.12.1637</a>

Tags changed:

  • ultrasound
  • abr certifying ultrasound

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