Ectopic pregnancy

• An ectopic pregnancy occurs when a fertilised ovum implants outside of the uterus. The most common location for ectopic pregnancy to occur is in one of the fallopian tubes, due to tubal dysfunction. 
• Classified by the anatomical site:

  • Almost always tubal (usually ampulla)
  • Interstitial (implantation in the interstitium where the fallopian tube meets the uterus)
  • Cervical
  • Ovarian
  • Can implant in the myometrium in a caesarean section scar
  • Isolated cases as far as the liver
• Risk factors:

  • Previous ectopic pregnancy (indicating damage to fallopian tube)
  • Assisted reproduction e.g. IVF
  • PID (adhesions)
  • Endometriosis
  • Tubal occlusion from sterilisation
  • Intrauterine contraception
• Symptoms:

  • Abdominal pain - usually unilateral
  • Pelvic pain
  • Amenorrhoea or a missed period
  • Vaginal bleeding
  • Dizziness, fainting or syncope
  • Shoulder tip pain (diaphragmatic irritation from rupture)
• Clinical exam:

  • Pelvic and bimanual
  • Pelvic or abdominal tenderness
  • Adnexal tenderness
  • Cervical excitation
  • Vaginal bleeding
  • Haemodynamic compromise if rupture and haemorrhage
• Any woman of reproductive potential who presents with abdominal or pelvic pain should always have a pregnancy test. If the pregnancy test is positive, they have an ectopic pregnancy until proven otherwise. 
• Bedside investigations:

  • Basic observations
  • Urine pregnancy test - would be positive
  • Urinalysis - infection - ectopic still needs excluding
  • Vaginal swabs - for STIs - can predispose to ectopic pregnancy
• Lab tests:

  • baseline - FBC, U&Es, coagulation, CRP - WCC may be raised, may be anaemia
  • Serum hCG - often used to monitor response to treatment
  • Group and save
• Transvaginal ultrasound scan is the most accurate method of confirming the presence of tubal ectopic pregnancy

  • Empty uterus
  • Adnexal mass
  • Free fluid in the peritoneum/pouch of Douglas - rupture
• Management:

  • Depends on the haemodynamic stability of the patient and investigation findings:
  • Expectant management
  • Medical management
  • Surgical management
  • If the ectopic pregnancy has ruptured, surgical management is usually required
• Expectant management:

  • Monitoring serum bHCG (usually 48 hours later) and performing serial ultrasound scans until spontaneously resolves, suitable when:
  • Pain free
  • Haemodynamically stable
  • Tubal ectopic visible on USS measuring <35mm (and no heartbeat)
  • hCG <1000
  • Able to return for follow up
• Medical management:

  • Methotrexate to stop growth, suitable when:
  • No significant pain
  • Unruptured ectopic with adnexal mass <35mm and no visible heartbeat
  • No intrauterine pregnancy seen on ultrasound - can have heterotopic pregnancy where intrauterine pregnancy occurs alongside ectopic
  • hCG <1500 - monitored to ensure it is declining
  • Able to return for follow up
• Surgical management:

  • Unable to return for follow up
  • Significant pain
  • Adnexal mass >35mm
  • Heartbeat visible on the scan
  • hCG >5000
  • Tubal ectopic - laparoscopic salpingectomy - remove ectopic and fallopian tube
  • Anti-D prophylaxis given to all rhesus negative women
• Salpingectomy:

  • Removal of ectopic pregnancy along with fallopian tube
  • Preferred in women with no other risks to their fertility - can affect future fertility
  • Reduces likelihood of a repeat ectopic pregnancy
• Salpingotomy:

  • Alternative that removes the ectopic pregnancy whilst preserving the fallopian tube
  • Usually offered to women with other fertility issues such as damage to the other fallopian tube
  • Carries greater risk of future ectopic pregnancy than a salpingectomy
• Complications:

  • Fallopian tube or uterine rupture
  • Secondary massive haemorrhage
  • Death
• Methotrexate:

  • Antimetabolite
  • Binds to enzyme dihydrofolate reductase
  • Competitive inhibition of folate dependent steps in nucleic acid synthesis
  • Kills the rapidly dividing ectopic pregnancy cells
• Use expectant management for women with a pregnancy of less than 6 weeks gestation who are bleeding but not in pain, and who have no risk factors (such as a previous ectopic pregnancy). Advise:

  • Return if bleeding continues or pain develops
  • Repeat a urine pregnancy test after 7-10 days and to return if it is positive
  • A negative pregnancy test means that the pregnancy has miscarried