Pathology > Gynecologic > Fallopian Tubes > Ectopic Pregnancy
Objectives Anat & Hist Inf. Diseases Ectopic Pregnancy

III. Ectopic Pregnancy


After completing this section you will be able to:

  • define ectopic pregnancy
  • list sites where ectopic pregnancies may implant
  • specify predisposing/etiologic factors
  • describe clinical features and predict clinical outcome

Definition: Ectopic pregnancy refers to the implantation of the developing blastocyst at any other site other than the endometrium.


Over 95% of ectopic pregnancies occur in the fallopian tubes. Within the tube, up to 80% occur in the ampulla, 25% in the isthmus, 5% in the infundibulum and up to 2% in the interstitial portion. Right-sided ectopics are commoner than left-sided. Other sites include the ovary, peritoneal cavity and uterine cervix.


PID is the most common antecedent factor. Abnormal tubal motility or mucosal adhesions that impede passage of the conceptus along the tube, endometriosis and previous pelvic surgery are other etiologic factors.

Clinical appearances

A woman with an ectopic tubal pregnancy may present with pelvic pain or anomalous bleeding following a period of amenorrhoea. The majority will present as an emergency with tubal rupture and hemorrhagic shock.

Ruptured ectopic tubal pregnancy involving the ampulla. Note the fetus protruding from site of rupture (12 o’clock).

Question: Which major blood vessel may be torn by a ruptured cornual/interstitial ectopic pregnancy?


Objectives Anat & Hist Inf. Diseases Ectopic Pregnancy