# Methotrexate in Ectopic Pregnancy

> NEET-PG OBG notes on methotrexate for ectopic pregnancy covering single-dose and multidose protocols, day 4-7 hCG rule and safety points.

- Canonical URL: https://prepelephant.com/topics/neet-pg/obstetrics-and-gynaecology/methotrexate-for-ectopic-pregnancy
- Exam / course: NEET-PG · Subject: Obstetrics and Gynaecology
- Publisher: PrepElephant (https://prepelephant.com) — Prepared and reviewed by the PrepElephant Academic Review Team
- First published: 2026-10-02
- Last updated: 2026-10-02
- How to cite: "Methotrexate in Ectopic Pregnancy", PrepElephant, https://prepelephant.com/topics/neet-pg/obstetrics-and-gynaecology/methotrexate-for-ectopic-pregnancy

## Direct answer

Methotrexate, a folate antagonist that kills rapidly dividing trophoblast, is the standard medical treatment of an unruptured ectopic pregnancy in a haemodynamically stable woman. The single-dose protocol gives 50 mg per square metre intramuscularly on day 1 with beta-hCG measured on days 4 and 7 — success is declared when hCG falls by at least 15 per cent between those two days, with weekly values followed until negative. Best results come with beta-hCG below about 5000 mIU/mL, a small adnexal mass, absent fetal cardiac activity and reliable follow-up; conception is avoided for three months after treatment.

## What you must remember

- Selection criteria: haemodynamic stability, unruptured ectopic without significant haemoperitoneum, beta-hCG preferably below 5000 mIU/mL, adnexal mass below about 3.5-4 cm, absent fetal cardiac activity, no contraindication to methotrexate and guaranteed follow-up.
- Single-dose protocol: methotrexate 50 mg/m² intramuscularly on day 1; measure hCG on days 4 and 7 (a day-4 rise is expected, not failure); a fall of at least 15 per cent from day 4 to day 7 predicts resolution; repeat weekly doses (up to three or four) if inadequate, then weekly hCG until below 5 mIU/mL.
- Multidose protocol: methotrexate 1 mg/kg on days 1, 3, 5 and 7 with folinic acid rescue 0.1 mg/kg on days 2, 4, 6 and 8, continued until hCG falls by 15 per cent over 48 hours — higher success in less favourable cases at the cost of side effects.
- Contraindications: rupture or shock, significant haemoperitoneum, breastfeeding, active pulmonary disease, peptic ulcer, hepatic or renal dysfunction, blood dyscrasias, immunodeficiency and unreliable follow-up; fetal cardiac activity and high hCG are relative contraindications.
- Side effects and interactions: stomatitis, gastritis, transient transaminitis, bone marrow suppression and photosensitivity; avoid non-steroidal anti-inflammatory drugs (additive toxicity) and folate supplements during treatment; abdominal pain on day 2-3 ("separation pain") is common and benign if the patient is stable.
- Adjuncts and aftercare: give anti-D to Rh-negative women; contraception for at least three months after the last dose; subsequent fertility is broadly comparable to surgery.
- Persistent trophoblast after salpingostomy (hCG plateau or rise) is a recognised indication for single-dose methotrexate, avoiding reoperation.

## Common confusion

Two protocol points trip candidates. First, the day-4 rise: hCG commonly rises before falling, and the verdict comes only from the day-4 to day-7 comparison. Second, separation pain: mild diffuse pain with stable vital signs on days 2-3 reflects tubal abortion or distension, whereas pain with tachycardia, hypotension, peritonism or a falling haematocrit means rupture and surgery.

## Exam-focused takeaway

Stems quote a protocol day and an hCG value, asking the interpretation or next step; others test selection criteria against contraindications. Expect recall of 50 mg/m², the 15 per cent day-4-to-day-7 rule, folinic acid rescue, three-month contraception, NSAID avoidance and anti-D. Separation-pain versus rupture vignettes close the set.

## Frequently asked questions

### What is the single-dose methotrexate protocol?

Methotrexate 50 mg per square metre intramuscularly on day 1 with hCG on days 4 and 7; a 15 per cent or greater fall predicts success, then weekly hCG until negative.

### Which patients are best suited to medical management?

Stable women with an unruptured ectopic, hCG below about 5000 mIU/mL, a small mass, no fetal cardiac activity and reliable follow-up.

### Why is hCG measured on both day 4 and day 7?

Because hCG often peaks around day 4; only the day-4 to day-7 decline predicts resolution.

### What are the major contraindications?

Rupture or haemodynamic instability, significant haemoperitoneum, hepatic, renal or haematological disease, active pulmonary disease, immunodeficiency and unreliable follow-up.

### Is methotrexate compatible with concurrent NSAIDs or pregnancy?

Neither — NSAIDs increase its toxicity, and conception is avoided for three months after the last dose because of teratogenicity.