Ectopic Pregnancy

  • embryo implants outside of the endometrial cavity (uterus)
  • 1/100 pregnancies
  • commonest locations: Ampullary (70%) >> isthmal (12%) > fimbrial (11%) > ovarian (3%) > interstitial (2%) > abdominal (1%)
  • fourth leading cause of maternal mortality, leading cause of death in first trimester

Etiology

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

Risk Factors

  • previous ectopic pregnancy (strongest risk factor)
  • smoking
  • infertility treatment (IVF pregnancies following ovulation induction [7% ectopic rate])
  • gynecologic: current IUD use, history of PID (especially infection with C. trachomatis), salpingitis and infertility
  • previous procedures: any surgery on fallopian tube (for previous ectopic, tubal ligation), abdominal surgery for ruptured appendix
  • structural: uterine leiomyomas, adhesions, abnormal uterine anatomy (e.g. T-shaped uterus)
  • More than half of patients with ectopic pregnancy have no risk factors

Diagnosis

Clinical Features

  • 4Ts and 1S:
    Temperature >38°C (20%)
    Tenderness: abdominal (90%) ± rebound (45%)
    Tenderness on bimanual examination, cervical motion tenderness
    Tissue: palpable adnexal mass (50%) (half have contralateral mass due to lutein cyst)
    Signs of pregnancy (e.g. Chadwick’s sign, Hegar’s sign)

Investigations

  • β-hCG levels
    normal doubling time with intrauterine pregnancy is 1.6-2.4 d in early pregnancy
    85% of ectopic pregnancies demonstrate abnormal β-hCG doubling
    does not provide information on location of implantation
  • ultrasound:
    only definitive if fetal cardiac activity is detected in the tube or uterus
    finding on transvaginal U/S is a tubal ring
  • suspect ectopic in case of empty uterus with β-hCG >5000 and no bleeding
  • laparoscopy (sometimes used for definitive diagnosis)

DDx of Lower Abdominal Pain

  • Urinary tract: UTI, kidney stones
  • GI: diverticulitis, appendicitis
  • Gyne: endometriosis, PID, fibroid
    (degenerating, infarcted, torsion), ovarian torsion, ovarian neoplasm, ovarian cyst, pregnancy-related

Treatment

goals

  • conservative (preserve tube if possible), maintain hemodynamic stability

surgical=laparoscopy

  • linear salpingostomy (cutting a hole in FT) an option if tube salvageable
  • salpingectomy (removal of the whole fallopian tube) if tube damaged or ectopic is ipsilateral recurrence
  • Rh negative should receive anti-D Rh immunoglobulin (RhoGAM) so that subsequent pregnancies will not be affected by hemolytic disease.
  • may require laparotomy if patient is unstable

medical=methotrexate (immunosuppressive)

indications

<3.5 cm unruptured ectopic
AND no fetal heart rate
AND b􏰎-hCG <5,000
AND no hepatic/renal/ hematological disease
AND able and willing to follow-up

indications

  • Vital signs unstable
  • ->3.5 cm unruptured ectopic
    OR fetal heart rate present
    OR 􏰎b-hCG >5,000
    OR hepatic/renal/haematological disease
    OR poor compliance OR unable to follow-up
  • 50 mg/m2 body surface area; given in a single IM dose --> minimal side effects (reversible hepatic dysfunction,
    diarrhea, gastritis, dermatitis)
  • follow β-hCG levels weekly until β-hCG is non-detectable
  • 82-95% success rate, but up to 25% will require a second dose

Suspected Ectopic Pregnancy

  1. Positive urine 􏰎-hCG
  2. Unilateral lower abdominal or pelvic pain
  3. Vaginal bleeding

If Ectopic Pregnancy Ruptures

• Acute abdomen with increasing pain
• Abdominal distention
• Shock (hypotensive)

  • we should monitor:
    -CBC to monitor for anemia
    -Blood type/screen
    -Transaminases to detect changes indicating hepatotoxicity from the medications
  • Beta-HCG to assess for success of treatment via a decrease in beta-HCG until reaches zero