Overview
Ectopic Pregnancy
1. Topic Overview (Clinical Overview)
Summary
Ectopic pregnancy is the implantation of an embryo outside the uterine cavity. ~97% occur in the Fallopian tube (Most commonly the Ampulla), with other sites including Ovary, Cervix, Interstitial (Cornual), Caesarean scar, and Abdomen. It is a life-threatening emergency if rupture occurs, causing massive intra-abdominal haemorrhage. The classic triad is Amenorrhoea (6-8 weeks) + Abdominal Pain + PV Bleeding, but presentations vary. Risk factors include previous ectopic, PID, tubal surgery, IVF, IUCD (Coil), and smoking. Diagnosis is via TVUSS (Transvaginal ultrasound – Empty uterus + Adnexal mass) and serum β-hCG (Suboptimal rise – Fails to double in 48 hours). Management options are Expectant (Falling hCG, Asymptomatic), Medical (Methotrexate), or Surgical (Laparoscopic Salpingectomy/Salpingotomy). Ruptured ectopic requires emergency surgery.
Key Facts
- Location: 97% Tubal (Ampulla > Isthmus > Fimbrial). Also Ovarian, Cervical, Interstitial, Scar.
- Incidence: ~1-2% of all pregnancies.
- Classic Triad: Amenorrhoea + Abdominal Pain + PV Bleeding.
- Shoulder Tip Pain: Sign of Haemoperitoneum (Blood irritating diaphragm).
- Diagnosis: TVUSS (Empty uterus + Adnexal mass). β-hCG (<66% rise in 48 hours is concerning).
- Treatment: Expectant, Medical (Methotrexate), Surgical (Salpingectomy/Salpingotomy).
Clinical Pearls
"Empty Uterus + Positive Pregnancy Test = Ectopic Until Proven Otherwise": A key diagnostic principle.
"Shoulder Tip Pain = Haemoperitoneum = Ruptured Ectopic": Blood under the diaphragm causes referred pain.
"β-hCG Should Double Every 48 Hours": Suboptimal rise suggests non-viable pregnancy (Ectopic or Miscarriage).
"Methotrexate is Teratogenic – 3 Months Contraception": Counsel patients after medical treatment.
Why This Matters Clinically
Ectopic pregnancy is a leading cause of maternal mortality in early pregnancy. Early diagnosis prevents rupture and saves lives.
2. Epidemiology
Incidence
- Overall: ~1-2% of all pregnancies.
- Increasing: Due to IVF, PID.
- Mortality: Leading cause of first-trimester maternal death in developed countries.
Risk Factors
| Factor | Notes |
|---|---|
| Previous Ectopic | ~10-15% recurrence risk. |
| Previous Tubal Surgery | Salpingostomy, Tubal ligation. |
| PID (Pelvic Inflammatory Disease) | Chlamydia, Gonorrhoea. Tubal damage. |
| IVF / ART | Heterotopic pregnancy (IUP + Ectopic) more common. |
| IUCD (Coil) | Pregnancy rare, but if occurs, higher proportion are ectopic. |
| Smoking | Impairs tubal motility. |
| Endometriosis | |
| Increasing Age |
3. Pathophysiology
Sites of Ectopic Pregnancy
| Site | Frequency | Notes |
|---|---|---|
| Ampulla (Tube) | ~70% | Most common. |
| Isthmus (Tube) | ~12% | Narrower. Rupture earlier. |
| Fimbrial (Tube) | ~11% | May result in tubal abortion. |
| Interstitial (Cornual) | ~2% | At uterine horn. High mortality if ruptures (Massive bleed). |
| Ovarian | ~3% | |
| Cervical | <1% | Haemorrhage risk with attempts to evacuate. |
| Caesarean Scar | ~1% (Increasing) | Implantation in previous scar. Risk of placenta accreta spectrum. |
| Abdominal | <1% | Rare. May progress to advanced gestation. |
Mechanism
- Fertilised ovum fails to reach uterine cavity.
- Implants in ectopic site (Usually damaged/diseased tube).
- Trophoblast invades tissue -> Growth.
- Eventually ruptures (Or resorbs/tubal abortion).
4. Clinical Presentation
Classic Triad
| Feature | Notes |
|---|---|
| Amenorrhoea | 6-8 weeks (Or longer). |
| Abdominal Pain | Unilateral iliac fossa. May be generalised if ruptured. |
| PV Bleeding | Usually light, "Dark/Brown" (Prune juice). |
Symptoms (Unruptured)
| Symptom | Notes |
|---|---|
| Lower Abdominal Pain | Unilateral. Dull/Sharp. |
| PV Bleeding | Light. May be absent. |
| Pregnancy Symptoms | Breast tenderness. Nausea. |
| Dizziness / Lightheadedness |
Signs of Rupture (EMERGENCY)
| Sign | Notes |
|---|---|
| Severe Abdominal Pain | Sudden onset. Generalised. |
| Shoulder Tip Pain | Referred pain from diaphragmatic irritation (Haemoperitoneum). |
| Peritonism | Guarding. Rebound. Rigidity. |
| Hypovolaemic Shock | Tachycardia, Hypotension, Pallor, Collapse. |
| Syncope |
Examination
| Finding | Notes |
|---|---|
| Abdominal Tenderness | Iliac fossa. Generalised if ruptured. |
| Cervical Excitation (Chandelier Sign) | Pain on moving cervix (Bimanual exam). |
| Adnexal Tenderness / Mass | May be palpable. |
| Closed Cervix | (Vs. Open in inevitable miscarriage). |
5. Investigations
Pregnancy Test
- Urinary β-hCG: Positive. First-line.
- Serum β-hCG: Quantitative. For monitoring.
β-hCG Dynamics
| Interpretation | Notes |
|---|---|
| Normal IUP | β-hCG doubles every 48 hours. |
| Suboptimal Rise (<66% in 48 hours) | Suggests failing pregnancy (Ectopic or Miscarriage). |
| Falling β-hCG | Suggests failing/resolving pregnancy. |
| Discriminatory Zone | β-hCG level above which IUP should be visible on TVUSS (~1,500-2,000 IU/L). |
If β-hCG above discriminatory zone and NO IUP seen on TVUSS -> Likely Ectopic.
Transvaginal Ultrasound (TVUSS)
| Finding | Interpretation |
|---|---|
| Intrauterine Pregnancy (IUP) | Gestational sac in uterus. (Excludes tubal ectopic, but Heterotopic possible after IVF). |
| Empty Uterus | PUL (Pregnancy of Unknown Location). May be early IUP, Ectopic, or Complete Miscarriage. |
| Adnexal Mass ("Blob Sign" / "Bagel Sign") | Suggestive of Ectopic. |
| Tubal Ring (Gestational Sac with Yolk Sac) | Definitive Ectopic. |
| Fetal Heartbeat in Adnexa | Definitive Ectopic. |
| Free Fluid in Pouch of Douglas | Echogenic = Blood. Suggests rupture/leaking. |
Bloods
| Test | Purpose |
|---|---|
| FBC | Haemoglobin (Baseline, Bleeding). |
| Group & Save / Crossmatch | If surgery anticipated / ruptured. |
| Serum β-hCG | Quantitative. Serial monitoring. |
6. Management
Principles
- ABC if Haemodynamically Unstable (Resuscitate, Crossmatch, Emergency Surgery).
- Confirm Diagnosis (TVUSS, β-hCG).
- Choose Treatment Based on: Stability, β-hCG level, Symptoms, US findings, Patient preference, Fertility wishes.
Treatment Options
| Option | Criteria | Procedure |
|---|---|---|
| Expectant | Asymptomatic. Falling β-hCG. No adnexal mass. β-hCG <1,500 IU/L and falling. | Serial β-hCG monitoring until 5 IU/L. |
| Medical (Methotrexate) | Stable. β-hCG <5,000 IU/L (Some protocols <3,000). No fetal heartbeat. Unruptured. Small mass (<35mm). Willing to comply with follow-up. | IM Methotrexate. Follow-up β-hCG on Day 4 & 7. May need repeat dose. |
| Surgical | Ruptured ectopic. Haemodynamically unstable. High β-hCG. Large mass. Fetal heartbeat. Failed medical treatment. Patient choice. | Laparoscopic Salpingectomy (Preferred if contralateral tube healthy). Salpingotomy (Tube-sparing, If fertility desired and contralateral tube damaged). |
Medical Treatment: Methotrexate
| Detail | Notes |
|---|---|
| Drug | Methotrexate (Folic acid antagonist. Inhibits trophoblast proliferation). |
| Dose | Single dose: 50mg/m² IM (Most common protocol). |
| Follow-Up | β-hCG on Day 4 and Day 7. Should fall by ≥15% between Day 4-7. |
| If <15% Fall | Consider second dose MTX or Surgery. |
| Success Rate | ~90% for single dose in selected patients. |
| Side Effects | Abdominal pain (Separation pain), Nausea, Mouth ulcers, Transient LFT rise. |
| Contraindications | Haemodynamically unstable. Rupture. Fetal heartbeat. β-hCG >,000. Significant mass. Liver/Kidney impairment. Breastfeeding. |
| Avoid After MTX | Pregnancy for 3 months (Teratogenic). Alcohol. NSAIDs. Folic acid. |
Surgical Treatment
| Procedure | Indication | Notes |
|---|---|---|
| Salpingectomy | First choice if contralateral tube healthy. Ruptured ectopic. | Removal of affected tube. Laparoscopic preferred. |
| Salpingotomy | If contralateral tube absent/damaged (Fertility preservation). | Tube-sparing. Higher risk of Persistent Trophoblast (Need to monitor β-hCG post-op). |
| Laparotomy | Haemodynamically unstable. Laparoscopy not feasible. | Emergency open surgery. |
Pregnancy of Unknown Location (PUL) Management
- If USS shows empty uterus and β-hCG positive but diagnosis unclear:
- Serial β-hCG at 48 hours.
- If rising adequately -> May be early IUP (Repeat scan).
- If suboptimal rise/falling -> Likely failing pregnancy (Ectopic or Miscarriage). Follow-up.
7. Complications
| Complication | Notes |
|---|---|
| Rupture | Life-threatening haemorrhage. Emergency surgery. |
| Persistent Trophoblast | After Salpingotomy. β-hCG remains elevated. May need MTX or further surgery. |
| Tubal Damage / Infertility | After Salpingectomy. Reduced fertility. IVF may be needed. |
| Future Ectopic | ~10-15% recurrence. |
| Hysterectomy | Rare. If Caesarean scar / Cervical ectopic uncontrolled. |
| Death | If undiagnosed rupture. |
8. Prognosis & Outcomes
| Scenario | Outcome |
|---|---|
| Early Diagnosed, Treated | Excellent. Fertility preserved (If tube spared). |
| Ruptured Ectopic | Higher morbidity. Tube usually removed. Fertility reduced. |
| Future Fertility | ~60-70% IUP rate after ectopic. ~10% recurrence. |
9. Special Populations
Heterotopic Pregnancy
- Coexisting IUP + Ectopic pregnancy.
- Rare naturally (~1:30,000). More common after IVF (~1:100).
- Do NOT assume IUP excludes ectopic after IVF.
Caesarean Scar Ectopic
- Implantation in previous CS scar.
- Risk of uterine rupture, Placenta accreta.
- Management often requires specialist input (MTX, Uterine artery embolisation, Surgery).
10. Evidence & Guidelines
Key Guidelines
| Guideline | Organisation | Notes |
|---|---|---|
| RCOG GTG 21 | RCOG | Diagnosis and Management of Ectopic Pregnancy. |
| NICE NG126 | NICE | Ectopic Pregnancy and Miscarriage. |
11. Exam Scenarios
Scenario 1:
- Stem: A woman with 6 weeks amenorrhoea presents with unilateral abdominal pain and light PV bleeding. Urine pregnancy test is positive. TVUSS shows empty uterus. β-hCG is 2,500 IU/L. What is the likely diagnosis?
- Answer: Ectopic Pregnancy (Positive pregnancy test + Empty uterus above discriminatory zone).
Scenario 2:
- Stem: What is the significance of shoulder tip pain in a woman with suspected ectopic pregnancy?
- Answer: Haemoperitoneum (Blood irritating diaphragm). Sign of ruptured ectopic. Emergency.
Scenario 3:
- Stem: What are the criteria for Methotrexate treatment of ectopic pregnancy?
- Answer: Haemodynamically stable. Low β-hCG (<5,000). Unruptured. No fetal heartbeat. Small mass. Compliant with follow-up.
12. Triage: When to Refer
| Scenario | Urgency | Action |
|---|---|---|
| Shoulder Tip Pain / Shock | Emergency | A&E. Resuscitate. Blood. Emergency Surgery. |
| Symptomatic Suspected Ectopic | Emergency | EPAU / Gynaecology. TVUSS. β-hCG. |
| PUL Requiring Follow-Up | Urgent | EPAU follow-up. Serial β-hCG. |
14. Patient/Layperson Explanation
What is an Ectopic Pregnancy?
An ectopic pregnancy is when a fertilised egg implants outside the womb (uterus), usually in the Fallopian tube. It cannot develop into a baby and can be dangerous if it ruptures.
What are the symptoms?
- Missed period.
- Tummy pain (Usually one-sided).
- Vaginal bleeding (Light, dark). Seek urgent help if you have sharp pain or shoulder tip pain – these could mean a rupture.
How is it treated?
- Watching and waiting: If the pregnancy is ending naturally.
- Medication (Methotrexate): An injection to stop the pregnancy growing.
- Surgery: Keyhole operation to remove the pregnancy (and sometimes the tube).
Key Counselling Points
- Future Pregnancies: "You can still get pregnant, but there is a slightly higher chance of another ectopic."
- After Methotrexate: "You need to wait 3 months before trying to conceive again."
- Warning Signs: "Come back immediately if you get worse pain, feel faint, or have shoulder tip pain."
15. Quality Markers: Audit Standards
| Standard | Target |
|---|---|
| TVUSS within 24 hours for suspected ectopic | >5% |
| β-hCG monitoring protocol followed | 100% |
| Laparoscopy for surgical management | >5% |
| Anti-D given to Rh-Negative women | 100% |
16. Historical Context
- First Successful Surgery for Ectopic: Robert Lawson Tait (1883). Salpingectomy saved the woman's life.
- Methotrexate for Ectopic: First used 1980s. Now standard medical management.
- Laparoscopy: Gold standard surgical approach since 1990s.
17. References
- NICE NG126. Ectopic Pregnancy and Miscarriage: Diagnosis and Initial Management. nice.org.uk
- RCOG GTG 21. Diagnosis and Management of Ectopic Pregnancy. rcog.org.uk
Last Reviewed: 2025-12-24 | MedVellum Editorial Team
Medical Disclaimer: MedVellum content is for educational purposes and clinical reference. Ectopic pregnancy is a medical emergency – seek immediate medical attention if suspected.