Ectopic pregnancy?

USSRU 2024

Positive pregnancy test with pain or bleeding; gynecology is choosing between follow-up, methotrexate, and surgery — with urgent operative assessment when instability and suspected hemoperitoneum coexist.

Answer the surgeon

Methotrexate vs laparoscopy — and with hemoperitoneum in an unstable patient, straight to the OR.

Your answer must state:

Definite intrauterine pregnancy present or not — an IUP makes a concurrent ectopic unlikely outside assisted reproduction, but does not exclude heterotopic pregnancy
Adnexal findings: tubal ring or mass separate from the ovary
Echogenic free fluid (hemoperitoneum) and how far it extends — pelvis only vs Morison's pouch
β-hCG for clinical correlation — do not use a single discriminatory cutoff to exclude or locate the pregnancy

Key and direct findings

1.Extrauterine gestational sac
A sac with yolk sac or embryo outside the uterus is definitive.
2.Tubal ring with an empty uterus
An echogenic ring in the adnexa, separate from the ovary and moving separately under probe pressure, with no IUP is a probable tubal ectopic pregnancy. It is definite when a yolk sac or embryo is seen within it.
Pitfall: The corpus luteum is the great mimic — it is IN the ovary (claw of ovarian tissue around it, moves with the ovary); a tubal ring is not.
3.Echogenic free fluid
Hemoperitoneum; quantify the extent — confined to the pelvis vs reaching Morison's pouch. In an unstable patient or with other high-suspicion findings, it warrants urgent gynecologic action but is not diagnostic of ectopic pregnancy by itself.

Supportive signs & checks

1.Intracavitary fluid
Central fluid without a yolk sac or embryo is not a definite IUP. Describe its morphology and location rather than using the ambiguous term ‘pseudosac’.
Pitfall: Calling intracavitary fluid an IUP can falsely reassure the team and delay ectopic-pregnancy care.
2.Pregnancy of unknown location
A positive hCG with neither a probable/definite IUP nor a probable/definite ectopic pregnancy on transvaginal US is a PUL, regardless of the hCG value — recommend serial hCG and repeat US as clinically appropriate.
3.Clear the adnexa even with an IUP
Heterotopic pregnancy is real in IVF patients — an IUP does not end the adnexal search there.

Wet-read snippets

Fill the blanks, then copy into your preliminary report.

Positive

Findings of ectopic pregnancy: no intrauterine gestational sac; ___ adnexal ___ (tubal ring / mass) separate from the ovary; ___ echogenic free fluid ___ (extending to Morison's pouch). β-hCG ___.

Negative

Intrauterine pregnancy (___ sac with yolk sac/embryo, CRL ___ mm); adnexa normal, no free fluid.

Equivocal

No intrauterine or definite extrauterine pregnancy (β-hCG ___) — pregnancy of unknown location; recommend serial β-hCG and repeat US.

Related workflows

Early pregnancy dating — Ultrasound

Sources

A lexicon for first-trimester US: SRU consensus recommendations — Rodgers SK et al. Radiology (2024)
Diagnostic clues to ectopic pregnancy — Lin EP et al. RadioGraphics (2008)

Content review: Content pending clinical review · 2026-07-15

Educational reference for trained clinicians. Verify every result against the cited original guideline before use. Not a substitute for clinical judgment or medical advice.