MBBS SAQ · Obstetrics & Gynaecology
Ectopic pregnancy — diagnosis, methotrexate and rupture resuscitation
NEET-PG SAQ on tubal ectopic pregnancy: beta-hCG discriminatory zone, TVS, methotrexate 50 mg/m2 criteria and follow-up, surgery choice, Anti-D, and ruptured ectopic shock.
On this page
Study tools
Exam tags
Write your answer
Saved on this device. No marking — you are the marker.
Question
A 27-year-old woman presents with 6 weeks of amenorrhoea, right iliac fossa pain for 12 hours, and dark vaginal spotting. She had chlamydia 2 years ago. Pulse 88, BP 110/70, mild right adnexal tenderness, no peritonism. Urine pregnancy test positive. Later, serum β-hCG is 2200 IU/L and TVS shows an empty uterus with a 2 cm right adnexal mass, no fetal cardiac activity, no free fluid. Three hours after admission she develops sudden severe pain, shoulder-tip pain, pulse 130 and BP 70/40. Answer all parts.
Model answer
Show the model answerShowHide
a) Diagnosis and risk factor (initial presentation)
Tubal ectopic pregnancy until proven otherwise — any reproductive-age woman with amenorrhoea + pain + bleeding + positive pregnancy test. Prior chlamydia/PID is the classic risk factor (tubal scarring/ciliary damage). Other risks: previous ectopic, tubal surgery, IVF, smoking, IUCD-associated pregnancy, genital TB in endemic regions.[1][2]
b) Diagnostic pathway
- Urine/serum β-hCG — confirms pregnancy.
- Quantitative serum β-hCG — interpret with TVS; discriminatory zone ~1500–2000 IU/L (assay/centre dependent): above this an intrauterine sac should usually be visible on TVS; empty uterus raises ectopic/PUL concern.
- Transvaginal ultrasound — empty uterus + adnexal mass/ring of fire ± free fluid.
- FBC, group and save/crossmatch, Rhesus status.
- Do not perform D&C as first-line diagnosis in a desired pregnancy.
c) Medical management of the stable unruptured ectopic
She is haemodynamically stable, mass 2 cm, no cardiac activity, hCG 2200 (<5000), no free fluid — methotrexate candidate if no contraindications (breastfeeding, active peptic ulcer, immunodeficiency, blood dyscrasia, hepatic/renal failure, heterotopic desire to keep IUP, inability to follow up).[1]
- Methotrexate 50 mg/m² IM single dose (day 1).
- Check β-hCG on day 4 and day 7 — need ≥15% fall between day 4 and 7; then weekly until undetectable.
- If fall <15%, second MTX dose or surgery.
- Counsel: abdominal pain common days 3–7 (separation pain vs rupture — safety-net); avoid folate, alcohol, NSAIDs, intercourse, sun; reliable contraception for 3 months after MTX.
- Anti-D 250 IU IM if Rh-negative (unsensitised).
d) Rupture — recognition and resuscitation
Sudden pain, shoulder-tip pain (diaphragmatic irritation from haemoperitoneum), tachycardia and hypotension = ruptured ectopic with haemorrhagic shock.
- ABC, high-flow oxygen, two large-bore IV cannulae, crystalloid while blood arrives.
- Activate massive haemorrhage pathway; crossmatch 4–6 units; O-negative if peri-arrest.
- Urgent senior O&G/anaesthesia/theatre — do not delay for further imaging.
- Surgical control — usually laparoscopic salpingectomy if the contralateral tube is healthy; salpingotomy considered if sole tube/fertility priority (higher persistent trophoblast risk; needs hCG follow-up). ESEP showed similar future pregnancy rates after salpingectomy vs salpingotomy when the other tube is healthy.[3]
- Anti-D if Rh-negative; counsel recurrence risk 10–15% and early TVS next pregnancy.
Common errors
- Treating a positive pregnancy test + empty uterus as miscarriage without ectopic work-up.
- Giving methotrexate when unstable, high hCG, cardiac activity, or large mass with free fluid.
- Delaying theatre for CT in a shocked ruptured ectopic.
- Forgetting Anti-D.
- No day-4/day-7 hCG schedule after MTX.
- Missing heterotopic pregnancy after IVF.
Examiner notes
- Always state pregnancy test first in women of reproductive age with abdominal pain.
- Quote MTX 50 mg/m² and 15% day 4–7 fall.
- Rupture = resuscitate and operate, not image.
- Mention Anti-D and future early-pregnancy surveillance.
References3ShowHide
- [1]ACOG. ACOG Practice Bulletin No. 193: Tubal Ectopic Pregnancy. Obstet Gynecol, 2018.PMID 29470343
- [2]Barnhart KT. Clinical practice. Ectopic pregnancy. N Engl J Med, 2009.PMID 19625718
- [3]Mol F, et al. Salpingotomy versus salpingectomy in women with tubal pregnancy (ESEP). Lancet, 2014.PMID 24499812