Ectopic Pregnancy
last authored: June 2009, Reuben Kiggundu
last reviewed:
Introduction
Ectopic pregnancy (Greek ektopos, or out of place) refers to the implantation of a fertilized egg outside of the uterine cavity. Ectopic pregnancies frequently rupture, leading to hemorrhage - the leading cause of first-trimester dealth due to pregnancy.
laparoscopic image provided by Dr Charles Hamm
Most ectopic pregnancies occur in the fallopian tubes (ampulla 81%, isthmus 12%, fimbria 5%), but can also occur in the cervix, ovary, cornual region of the uterus, and the abdominal cavity.
The abnormally implanted blastocyst grows and draws its blood supply from the site of abnormal implantation. As the gestation enlarges, it creates the potential for rupture and hemorrhage - one of its most dangerous compications.
Causes and Risk Factors
All women of reproductive age are at risk, though rates increase in women over 35.
Anything that hampers the migration of the embryo to the endometrial cavity can predispose to ectopic pregnancy.
- pelvic inflammatory disease - commonest Chlamydia trachomatis (10-15% chance with future pregnancy)
- history of prior ectopic pregnancy (15-20% recurrence rate)
- history of tubal surgery and conception after tubal ligation
- use of infertility drugs or assisted reproductive technology
- use of intrauterine devices
- increasing age
- smoking
- salpingitis isthmica nodosum
- previous DES exposure
- T-shaped uterus
- prior abdominal surgery
However, over half of all cases of ectopic pregnancy occur in women with none of these risk factors.
Signs and Symptoms
- history
- physical exam
History
Only 50% of patients present typically.
The classic clinical triad of ectopic pregnancy includes:
- lower abdominal pain
- amenorrhea
- vaginal bleeding
Other symptoms include:
- dizziness, fainting
- passage of tissue
- those common to early pregnancy (nausea, breast fullness, fatigue, heavy cramping etc.)
Inquire into:
- menstrual history (LMP)
- sexual history
- constraceptive use
- gynecologic history (surgery, infections)
Physical exam may reveal:
- unstable vitals: tachycardia, hypotension)
- adnexal tenderness or mass
- abdominal tenderness, rebounding, or guarding
- Cullen sign: blue discoloration around umbilicus suggesting retroperitoneal hemorrhage
- uterine enlargement
- fever
- orthostatic hypotension
Investigations
- lab investigations
- diagnostic imaging
Lab Investigations
- beta-HCG: quantitative testing can be done at 48h intervals
- serum progesterone may distinguish between viable and nonviable pregnancy
- CBC
- Rh type
- crossmatch
Diagnostic Imaging
Transvaginal ultrasound (TVUS) is the preferred modality to identify extrauterine pregnancy. However, a negative ultrasound does not exclude ectopic pregnancy.
Ectopic findings include:
- complex adnexal mass
- fluid-filled adnexal mass
- free fluid in the peritoneal cavity
- gestational sac in the cornual area
- intracervical location
CT, MRI, or Doppler flow may also be done, though are not as helpful.
Differential Diagnosis
Other possible conditions include:
- normal pregnancy
- appendicitis
- urinary tract infection
- ovarian torsion
- ovarian cyst
- salpingitis
- ruptured corpus luteum cyst
- threatened abortion
Pathophysiology
Damage to the cilia in Fallopian tubes is frequently responsible for ectopic pregnancy, caused by factors such as pelvic inflammatory disease (PID) or surgery.
Treatments
laparoscopic image provided by Dr Charles Hamm
Initial focus should be on the ABC's to stabilize the patient:
- oxygen as needed
- two large bore IVs and fluid resuscitation
- CBC and cross-match
Rhogam should be given as appropriate.
Medications
methotrexate is the primary nonsurgical treatment. It can be used in situations of:
- stable patient
- no signs of active bleeding
- patient can be trusted to follow-up
Indications include:
- unruptured mass <3.5 cm
- no fetal activity
- desire for future fertility
Surgery
Surgery must be performed if the patient is hemodynamically unstable. Laparatomy or laparascopy may be performed, followed by salpingectomy or salpingostomy.
Consequences and Course
Ectopic pregnancy can lead to massive hemorrhage, infertility, and death.
Between 25-30% of women will have another ectopic pregnancy if they conceive.
Resources and References
Murray H et al. 2005. Diagnosis and treatment of ectopic pregnancy. CMAJ. 173(8).
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