11. Ectopic Pregnancy

Question 1

Define: Ectopic pregnancy (1)

Answer 1

• embryo implants outside of the endometrial cavity

Question 2

Name normal sites of implantation for ectopic pregnancy (7)

Answer 2

Question 3

Name sites of ectopic pregnancy implantation in order of frequency (6)

Answer 3

ampullary (70%) >> isthmal (12%) > fimbrial (11%) > ovarian (3%) > interstitial (2%) > abdominal (1%)

Question 4

Describe epidemiology: Ectopic Pregnancy (4)

Answer 4

• 1/100 pregnancies
• fourth leading cause of maternal mortality, leading cause of maternal death in first trimester
• increase in incidence over the last 3 decades
• three commonest locations for ectopic pregnancy: ampullary (70%), isthmic (12%), fimbrial (11%)

Question 5

Describe etiologies: Ectopic Pregnancy (4)

Answer 5

• 50% due to damage of fallopian tube cilia following PID
• intrinsic abnormality of the fertilized ovum
• conception late in cycle
• transmigration of fertilized ovum to contralateral tube

Question 6

Describe algorithm for suspected ectopic pregnancy (figure)

Answer 6

Question 7

Name: Contraindications to Methotrexate Therapy for Ectopic Pregnancy (8)

Answer 7

• Abnormalities in hematologic, hepatic or renal function
• Immunodeficiency
• Active pulmonary disease
• Peptic ulcer disease
• Hypersensitivity to methotrexate
• Heterotopic pregnancy with coexisting viable intrauterine pregnancy
• Breastfeeding
• Unwilling or unable to adhere to methotrexate protocol

Question 8

Name risk factors: Ectopic pregnancy (6)

Answer 8

• previous ectopic pregnancy
• gynecologic
  
  • current IUD use – increased risk of ectopic if pregnancy occurs
  • history of PID (especially infection with C. trachomatis), salpingitis
  • infertility
• infertility treatment (IVF pregnancies following ovulation induction (7% ectopic rate))
• previous procedures
  
  • any surgery on fallopian tube (for previous ectopic, tubal ligation, etc.)
  • abdominal surgery for ruptured appendix, etc.
• smoking
• structural
  
  • uterine leiomyomas
  • adhesions
  • abnormal uterine anatomy (e.g. T-shaped uterus)

Question 9

Describe investigations: Ectopic pregnancy (4)

Answer 9

• serial β-hCG levels; normal doubling time with intrauterine pregnancy is 1.6-2.4 d in early pregnancy
  
  • rise of <20% of β-hCG (1.6-2.4 d) is 100% predictive of a non-viable pregnancy
  • prolonged doubling time, plateau, or decreasing levels before 8 wk implies nonviable gestation but does not provide information on location of implantation
  • 85% of ectopic pregnancies demonstrate abnormal β-hCG doubling
• ultrasound
  
  • U/S is only definitive if fetal cardiac activity is detected in the tube or uterus
  • specific finding on transvaginal U/S is a tubal ring
• suspect ectopic in case of empty uterus by TVUS with β-hCG >2000-3000 mIU/ml
• laparoscopy (sometimes used for definitive diagnosis)

Question 10

Describe treatment: Ectopic pregnancy (4)

Answer 10

• goals of treatment: conservative (preserve tube if possible), maintain hemodynamic stability
• surgical = laparoscopy
  
  • linear salpingostomy an option if tube salvageable, however, patient must be reliable to follow-up with weekly β-hCG
  • salpingectomy if tube damaged or ectopic is ipsilateral recurrence
  • 15% risk of persistent trophoblast if salpingectomy; must monitor β-hCG titres weekly until they reach non-detectable levels
  • consider Rhogam® if Rh negative
  • patient may require laparotomy if unstable, extensive abdominal surgical history, etc.
• medical = methotrexate
  
  • use 50 mg/m2 body surface area; given in a single IM dose
  • this is 1/5 to 1/6 chemotherapy dose, therefore minimal side effects (reversible hepatic dysfunction, diarrhea, gastritis, dermatitis)
  • follow β-hCG levels weekly until β-hCG is non-detectable
    
    • plateaued or rising levels suggest persistent trophoblastic tissue requiring further treatment
  • 82-95% success rate, but up to 25% will require a second dose
    
    • administer a second dose if β-hCG does not decrease by at least 15% between days 4 and 7
  • tubal patency following methotrexate treatment approaches 80%
• expectant management is an option for patients who are clinically stable, reliable for follow-up, and have β-hCG levels that are low and declining

Question 11

Describe prognosis: Ectopic pregnancy (3)

Answer 11

• 9% of maternal deaths during pregnancy attributed to ectopic pregnancy
• 40-60% of patients will become pregnant again after surgery
• 10-20% will have subsequent ectopic pregnancy

Question 12

Any woman presenting with abdominal pain, vaginal bleeding and amenorrhea is ___ until proven otherwise

Answer 12

an ectopic pregnancy

Question 13

Describe: Presentation of Ectopic Pregnancy Ruptures (3)

Answer 13

• Acute abdomen with increasing pain
• Abdominal distention
• Shock

Question 14

Describe: Management of Abortions (3)

Answer 14

• Always rule out an ectopic
• Always check Rh; if negative, give Rhogam®
• Always ensure patient is hemodynamically stable