Table of Contents
Overview – Ectopic Pregnancy
Ectopic pregnancy refers to the implantation of a fertilised egg outside the uterine cavity, most commonly within the fallopian tubes. It is a time-critical condition that can lead to tubal rupture, haemorrhage, and maternal mortality if not diagnosed and managed early. Recognising the risk factors and classic clinical presentation is crucial for timely intervention.
Definition
- Implantation of a fertilised ovum outside the uterus, most commonly in the fallopian tubes
Aetiology
- 50% idiopathic
- Risk factors:
- Tubal obstruction or stricture
- Pelvic inflammatory disease (PID)
- Intrauterine devices (IUDs)
- Endometriosis
Morphology / Pathophysiology
Macroscopic
- 90% occur in fallopian tubes
- May also occur in abdominal cavity, cervix, or ovaries
Microscopic
- Normal trophoblastic (placental) invasion and development — but in ectopic locations

Clinical Features
- Occurs in approximately 1% of pregnancies
- May mimic a normal early pregnancy:
- Missed periods
- Nausea
- Breast tenderness
- Red flags:
- Sharp, stabbing abdominal/pelvic pain
- Vaginal spotting/bleeding
- If ruptured: Peritonitis, referred shoulder pain, signs of shock → Medical Emergency
Investigations
- β-hCG:
- Positive test indicates pregnancy
- Monitor trend over 48-hour intervals if diagnosis is unclear
- Transvaginal or abdominal ultrasound:
- Key to locating the gestational sac
- If inconclusive, repeat scan every 2–3 days in parallel with β-hCG levels
Management
- Medical treatment (if early/unruptured and stable):
- Methotrexate ± Misoprostol
- Surgical treatment:
- Laparoscopic salpingotomy or salpingectomy
- Indicated in unstable patients, or if contraindications to methotrexate
Complications
- Tubal rupture → Intraperitoneal bleeding → Hypovolaemic shock → Death
- Spontaneous abortion
- Chorioamnionitis
- Infertility (due to tubal damage or removal)
Prognosis
- Favourable if diagnosed and treated early
- May result in future fertility issues, especially with bilateral tubal disease or rupture
Summary – Ectopic Pregnancy
Ectopic pregnancy is a life-threatening implantation of a fertilised ovum outside the uterine cavity. Early recognition, investigation using β-hCG and ultrasound, and appropriate medical or surgical management are critical to avoid serious complications. For a broader context, see our Obstetrics Overview page.