Ectopic pregnancy
Implantation outside the uterus (usually ampulla of tube)
Overview
Implantation of a pregnancy outside the uterine cavity — most commonly the fallopian tube. A leading cause of first-trimester maternal death; presents with pain and bleeding at 6–8 weeks and can rupture catastrophically.
Recognise
- 6–8 weeks amenorrhoea then lower abdominal pain (often unilateral) ± vaginal bleeding
- Shoulder-tip pain (diaphragmatic irritation), dizziness/collapse if ruptured
- Cervical motion tenderness, adnexal tenderness
- Risk: previous ectopic, PID, tubal surgery, IUD, IVF
Red flags
- Haemodynamic instability/collapse, shoulder-tip pain, peritonism → rupture → resuscitate + emergency surgery
Differentials & how to tell them apart
Investigations
Urine βhCG positive → transvaginal USS (empty uterus + adnexal mass/free fluid). Serial serum βhCG (suboptimal rise) in pregnancy of unknown location. Clinical state outweighs hCG numbers.
Management
Salpingectomy (laparoscopic) — or methotrexate if criteria met
- 1Unstable / significant pain / large (>35 mm) / fetal heartbeat / hCG high: surgical (laparoscopic salpingectomy; salpingotomy if contralateral tube damaged).Gate: Methotrexate is an option ONLY if: stable, minimal pain, unruptured, <35 mm, no fetal heartbeat, hCG <1500 (up to 5000), able to attend follow-up
- 2Expectant management for selected very early, stable, falling-hCG cases. Anti-D if rhesus-negative and surgical.
Key points
The methotrexate eligibility criteria are high-yield (stable, small, low hCG, no heartbeat, reliable follow-up). Always do a pregnancy test in any woman of reproductive age with abdominal pain.
Monitor & prognosis
Serial hCG to zero (medical/expectant); observe for rupture.
Good with prompt treatment; affects future fertility.
Source: NICE NG126; CKS Ectopic