Ectopic pregnancy
Exam Tips
- In any reproductive-age patient with abdominal pain or vaginal bleeding, always rule out pregnancy first; ectopic can mimic UTI or GI illness.
- Do not be falsely reassured by absence of risk factors (around one-third have none).
- Classic triad (pain, amenorrhoea, bleeding) is helpful but not mandatory; presentation ranges from asymptomatic to collapse.
- Use integrated interpretation of symptoms + TVUS + serial beta-hCG; single hCG cut-offs are insufficiently reliable alone.
- Rupture clues: shoulder-tip pain, syncope, tachycardia, hypotension, pallor, peritonism; treat as emergency.
- Ultrasound revision: recognise adnexal tubal ring and free fluid patterns (see Figure: tubal ring sign in standard early-pregnancy ultrasound teaching texts).
Definition
Ectopic pregnancy is implantation of a fertilised ovum outside the endometrial cavity, most commonly in the fallopian tube (especially ampullary segment). It is a time-critical cause of pain and bleeding in early pregnancy because trophoblastic invasion can erode local vessels, leading to tubal rupture and life-threatening intra-abdominal haemorrhage.
Pathophysiology
Most cases arise from impaired embryo transport through the tube due to prior epithelial/ciliary injury (for example after pelvic inflammatory disease or surgery), altered smooth-muscle peristalsis, and local inflammation. The embryo implants ectopically, and invasive trophoblast cannot be accommodated safely by tubal tissue; progressive distension and vascular invasion can cause tubal abortion or rupture. Non-tubal sites (ovarian, cervical, caesarean-scar, interstitial/cornual, abdominal) are less common but can bleed catastrophically because diagnosis is often delayed. Heterotopic pregnancy (coexisting intrauterine and ectopic gestations) is uncommon naturally but increased with assisted conception.
Risk Factors
- Previous ectopic pregnancy (recurrence risk rises with number of prior ectopics)
- Pelvic inflammatory disease/salpingitis
- Previous tubal or pelvic surgery (including sterilisation failure, tubal reconstruction, caesarean section)
- Assisted reproduction (especially IVF) and infertility history
- Maternal age over 35 years
- Cigarette smoking
- Current pregnancy with intrauterine contraception in situ
- Multiple sexual partners (indirect STI/tubal damage risk)
- In-utero diethylstilbestrol exposure
- Black ethnicity (epidemiologically higher risk in UK data)
Clinical Features
Symptoms
- Unilateral or central lower abdominal/pelvic pain
- Amenorrhoea or missed period
- Vaginal bleeding (often light/irregular, may include clots)
- Shoulder-tip pain
- Dizziness, presyncope, or syncope
- Gastrointestinal symptoms (vomiting, diarrhoea) that can mimic GI disease
- Urinary symptoms or rectal pressure/pain on defecation
Signs
- Abdominal and/or pelvic tenderness
- Adnexal tenderness
- Cervical motion tenderness
- Peritoneal irritation (rebound/guarding)
- Pallor, tachycardia, hypotension
- Abdominal distension
- Shock/collapse in ruptured ectopic pregnancy
Investigations
Management
Lifestyle Modifications
- Immediate safety-net advice: attend emergency care urgently for worsening pain, dizziness, syncope, shoulder-tip pain, heavy bleeding, or collapse.
- Ensure reliable follow-up and clear written instructions; rupture can occur even with initially mild symptoms.
- Smoking cessation and optimisation of sexual/reproductive health to reduce future tubal risk.
Pharmacological Treatment
Antimetabolite
- Methotrexate 50 mg/m2 intramuscular single-dose regimen
Used in selected stable, unruptured ectopic pregnancy with low-risk features and capacity for close hCG follow-up. Check baseline FBC, U&E, LFTs. Contraindications include haemodynamic instability/rupture, significant liver or renal disease, blood dyscrasia, active pulmonary disease, immunodeficiency, breastfeeding, peptic ulcer disease, and inability to comply with follow-up. Safety advice: avoid alcohol, folic acid supplements, NSAIDs, and conception for at least 3 months after treatment.
Anti-D prophylaxis (RhD-negative, unsensitised)
- Anti-D immunoglobulin 250 IU IM (50 micrograms) after surgical management of ectopic pregnancy
Give according to local early-pregnancy protocol and gestation-specific transfusion guidance.
Surgical / Interventional
- Urgent laparoscopic surgery for suspected rupture or significant intraperitoneal bleeding; laparotomy if unstable.
- Salpingectomy is commonly preferred when the contralateral tube is healthy.
- Salpingotomy may be considered for fertility preservation when contralateral tubal disease exists, with mandatory postoperative hCG surveillance for persistent trophoblast.
- Expectant management is possible in carefully selected stable patients with low and falling hCG, minimal symptoms, and robust follow-up.
Complications
- Tubal rupture with massive intra-abdominal haemorrhage and haemodynamic shock
- Maternal death (important cause of death in early pregnancy)
- Recurrent ectopic pregnancy
- Future subfertility or reduced spontaneous intrauterine pregnancy chance in some groups
- Persistent trophoblastic tissue after conservative surgery
- Treatment-related adverse effects (for example methotrexate hepatotoxicity, nephrotoxicity, myelosuppression, pulmonary toxicity; operative injury to surrounding structures)
- Psychological morbidity including grief, anxiety, and depression after pregnancy loss
Prognosis
With early diagnosis and appropriate treatment, outcomes are usually good and many patients subsequently conceive spontaneously (around two-thirds in cohort data). Recurrence risk is clinically significant (about 10% after one prior ectopic and higher with multiple prior ectopics), so early scan in future pregnancies is essential. Delay in diagnosis markedly worsens prognosis because rupture can occur rapidly and unpredictably.
Sources & References
🏥BMJ Best Practice(1)
✅NICE Guidelines(1)
- Ectopic pregnancy[overview]