Ectopic Pregnancy – High-Yield MRCOG/MCPS Summary (NICE + RCOG Green-top Guideline)

This summary combines the key recommendations from NICE Ectopic Pregnancy and Miscarriage Guideline (NG126) and the RCOG Green-top Guideline on Tubal Ectopic Pregnancy, focusing on points commonly tested in exams.

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Definition

An ectopic pregnancy is implantation of a fertilized ovum outside the endometrial cavity.

Sites

Site Frequency

Ampulla of tube 70% (most common)
Isthmus 12%
Fimbria 11%
Interstitial (cornual) 2–4%
Ovary <3%
Cervix Rare
Caesarean scar Rare but increasing
Abdomen Very rare
Heterotopic pregnancy Rare naturally, ↑ after IVF

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Risk Factors

Remember Previous Tubal Damage

High-risk factors

Previous ectopic pregnancy (10–20% recurrence)

Previous tubal surgery

Previous sterilization failure

Previous PID

Chlamydia infection

Assisted reproductive techniques (IVF)

IUCD in situ (overall pregnancy risk low, but if pregnancy occurs → relatively higher chance ectopic)

Endometriosis

Smoking

Increasing maternal age (>35)

Congenital tubal abnormalities

Remember

Half of ectopic pregnancies have NO identifiable risk factor.

Exam favorite.

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Clinical Presentation

Classic triad

Amenorrhoea

Lower abdominal pain

Vaginal bleeding

Only about 50% present with all three.

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Symptoms

Missed period

Positive pregnancy test

Unilateral pain

Vaginal spotting

Shoulder tip pain

Pain on defecation

Collapse

Syncope

Dizziness

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Signs

Stable patient

Mild tenderness

Cervical excitation

Adnexal tenderness

Adnexal mass

Ruptured ectopic

Tachycardia

Hypotension

Pallor

Abdominal guarding

Rebound tenderness

Distension

Shock

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Differential Diagnosis

Miscarriage

Corpus luteum cyst

Ovarian torsion

Appendicitis

PID

UTI

Renal colic

—

Initial Assessment

Always assess

ABCDE

First priority

Assess:

Airway

Breathing

Circulation

Disability

Exposure

—

Immediate Investigations

Pregnancy test

FBC

Blood group

Rh status

Crossmatch if unstable

Serum β-hCG

TVS

—

Serum β-hCG

Used

NOT to diagnose ectopic

Rather

To interpret ultrasound findings

and

Follow patients managed conservatively or medically.

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Transvaginal Ultrasound (TVS)

Investigation of choice

Diagnostic findings

Definite ectopic

Extrauterine gestational sac

Yolk sac

Embryo ± cardiac activity

Suggestive findings

Adnexal mass

Tubal ring

Free pelvic fluid

Empty uterus

—

Pseudogestational sac

Exam favorite

Occurs inside uterus

BUT

Not a true gestational sac.

—

Pregnancy of Unknown Location (PUL)

Definition

Positive pregnancy test

BUT

No intrauterine or ectopic pregnancy seen on TVS.

Management

Repeat β-hCG after 48 hours

Repeat TVS

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β-hCG Patterns

Normal viable pregnancy

Increase

≥63% in 48 hours (NICE)

Failing pregnancy

Falling β-hCG

Ectopic

Usually

Suboptimal rise

Plateau

or

Slow fall

Remember

β-hCG pattern ALONE

Cannot diagnose ectopic.

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NICE hCG Follow-up

Repeat after 48 hours

Interpret trends together with ultrasound

Never rely on a single β-hCG.

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Discriminatory Zone

Traditional

1500–2000 IU/L

BUT

NICE advises

Do NOT diagnose ectopic solely because β-hCG exceeds the discriminatory level and no intrauterine pregnancy is seen.

Repeat assessment.

Exam favorite.

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Management Principles

Depends upon

Haemodynamic stability

Symptoms

β-hCG

Ultrasound findings

Patient preference

Follow-up reliability

—

Three Management Options

1. Expectant

2. Medical

3. Surgical

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Expectant Management

Suitable if

Clinically stable

Minimal pain

Small ectopic

No fetal heartbeat

Falling β-hCG

Reliable follow-up

—

NICE criteria

Usually

β-hCG

<1000 IU/L

and already falling.

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Follow-up

β-hCG

Twice weekly initially

Then weekly

Until

Negative

(<20 IU/L or local protocol)

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Medical Management

Drug

Methotrexate

—

Mechanism

Folate antagonist

Stops trophoblastic proliferation.

—

Suitable when

Stable

No rupture

Minimal symptoms

Reliable follow-up

No contraindications

No fetal cardiac activity

Small ectopic

Usually

β-hCG

<1500 IU/L (NICE preferred)

RCOG notes success decreases as β-hCG rises; many centres use higher thresholds in selected patients.

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Contraindications

Absolute

Breastfeeding

Immunodeficiency

Liver disease

Renal disease

Blood dyscrasia

Active lung disease

Peptic ulcer

Sensitivity to MTX

Ruptured ectopic

Haemodynamic instability

Relative

Large ectopic

Fetal heartbeat

High β-hCG

—

Dose

Single dose

50 mg/m² IM

—

Follow-up

Measure β-hCG

Day 4

Day 7

Expected

≥15% fall from Day 4 to Day 7

If achieved

Weekly β-hCG

Until negative.

—

If

Less than 15% fall

↓

Second dose

OR

Surgery

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Advice After Methotrexate

Avoid

Pregnancy for 3 months

Alcohol

NSAIDs

Folic acid supplements

Heavy exercise

Sexual intercourse until symptoms settle

Seek help

If severe pain

Because rupture may still occur.

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Surgical Management

Indications

Haemodynamic instability

Rupture

Contraindications to MTX

Failed MTX

Patient preference

Persistent pain

Large ectopic

Fetal cardiac activity

Unable to follow-up

—

Surgical Options

Salpingectomy

Removal of tube

Preferred

If opposite tube normal.

—

Salpingotomy

Tube preserved

Used when

Contralateral tube damaged

Future fertility important

—

Salpingotomy

Advantages

Preserves tube

Possible fertility benefit if opposite tube unhealthy.

Disadvantages

Persistent trophoblast

Need β-hCG follow-up

Repeat surgery possible

—

Persistent Trophoblast

Higher after

Salpingotomy

Requires

Weekly β-hCG

Until negative

May require methotrexate.

—

Laparoscopy vs Laparotomy

Stable

Laparoscopy

Gold standard

Unstable

Emergency laparotomy may be required.

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Anti-D Immunoglobulin

Offer to

All RhD-negative women with a surgically managed ectopic pregnancy.

Routine anti-D is not required for women receiving methotrexate or expectant management unless there is another sensitising event or local policy indicates otherwise.

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Interstitial (Cornual) Pregnancy

Higher mortality

Because rupture occurs late

Massive haemorrhage

Management

Specialist centre

Methotrexate in selected cases

Cornual resection

Occasionally hysterectomy

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Caesarean Scar Pregnancy

Increasing incidence

Diagnosis

TVS

Management

Specialist MDT

Avoid curettage alone

Options include

Methotrexate

Local injection

Surgical excision

UAE with surgery in selected cases

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Cervical Pregnancy

Massive bleeding risk

Treatment

Usually conservative

Methotrexate

Balloon tamponade

UAE

Surgery if needed

—

Ovarian Pregnancy

Rare

Usually diagnosed during surgery

Treatment

Ovarian wedge resection

—

Abdominal Pregnancy

Rare

Dangerous

Requires specialist management

Heterotopic Pregnancy

Simultaneous

Intrauterine pregnancy

Ectopic pregnancy

Higher after IVF

Important point

Seeing an intrauterine pregnancy does NOT completely exclude ectopic pregnancy in IVF patients.

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Complications

Tubal rupture

Haemorrhage

Shock

Maternal death (rare)

Persistent trophoblast

Infertility

Recurrent ectopic

Adhesions

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Future Fertility

Approximate recurrence

10%

After one ectopic

Risk increases after two.

Future intrauterine pregnancy rates are generally similar after salpingectomy and salpingotomy when the opposite tube is healthy.

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Future Pregnancy Advice

Early pregnancy assessment

TVS at

6–7 weeks

to confirm intrauterine pregnancy.

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Counseling

Explain

Risk of recurrence

Importance of early scan

Warning symptoms

Emotional support

Common MRCOG/MCPS/ FCPS Exam Pearls

✅ Ampulla is the commonest site (≈70%).

✅ Half of women have no risk factors.

✅ Shoulder-tip pain suggests haemoperitoneum due to diaphragmatic irritation.

✅ TVS is the first-line imaging test.

✅ A pregnancy of unknown location requires serial β-hCG and repeat TVS, not immediate treatment.

✅ A normal early intrauterine pregnancy should show a ≥63% rise in β-hCG over 48 hours.

✅ Do not diagnose ectopic based only on a single β-hCG level above the discriminatory zone.

✅ Methotrexate follow-up: Day 4 → Day 7 → ≥15% fall required.

✅ Salpingectomy is preferred when the contralateral tube is healthy.

✅ Salpingotomy requires serial β-hCG because of the risk of persistent trophoblast.

✅ Anti-D is recommended for RhD-negative women undergoing surgical management of ectopic pregnancy.

This covers the high-yield points from NICE NG126 and the RCOG Green-top Guideline on Tubal Ectopic Pregnancy most relevant for MRCOG Part 2, MRCOG Part 3, FCPS, and MCPS examinations.