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Dr Pixel 2.0Women's imaging diagnosis

PLATFORM FOR EDUCATION AND DECISION SUPPORT IN WOMEN'S IMAGING

Interactive checklist

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References

  1. National Institute for Health and Care Excellence (NICE). Ectopic pregnancy and miscarriage: diagnosis and initial management. NICE guideline NG126. London: NICE; 2019. Updated 23 Aug 2023. Available at: https://www.nice.org.uk/guidance/ng126
Understand the findings

Ultrasound findings of ectopic pregnancy

Read the didactic cards and, in the checklist, select the findings present. The result is updated automatically and does not replace clinical judgment.

From the most definitive finding to the most uncertain

Hierarchy of ultrasound findings (NICE)

Indicates tubal ectopicNICE 1.4.17
  • Mobile adnexal mass separate from the ovary ("sliding sign") with gestational sac containing yolk sac.
  • Mobile adnexal mass separate from the ovary with gestational sac and fetal pole (with or without heartbeat).
High probabilityNICE 1.4.18
  • Mobile adnexal mass separate from the ovary with empty gestational sac ("tubal ring"/"bagel sign").
  • Complex, heterogeneous, mobile adnexal mass separate from the ovary.
Possible ectopicNICE 1.4.19
  • Empty uterus.
  • Pseudosac (fluid in the uterine cavity) — differentiate from early intrauterine sac (double decidual sign).

Free fluid / hemoperitoneum (TAUS or USTV)

  • Moderate to large amount of free fluid in the peritoneal cavity or pouch of Douglas may represent hemoperitoneum.

If present, consider intrauterine and adnexal findings, clinical presentation and hCG before concluding. NICE 1.4.20 (2019).

Heterotopic (TAUS or USTV)

  • When performing abdominal or transvaginal ultrasonography in early pregnancy, examine the uterus and adnexa to assess for heterotopic pregnancy.

NICE 1.4.21 (2019).

Examiner qualification

  • Examinations must be performed or supervised/reviewed by qualified professionals with training and experience in ectopic pregnancy diagnosis.

NICE 1.4.22 (2012, amended 2019).

Before concluding, consider intrauterine and adnexal findings on examination, clinical presentation and serum hCG levels (NICE 2019/2023).

Common questions

Frequently asked questions about ectopic pregnancy

Which ultrasound findings indicate tubal ectopic pregnancy?+
A mobile adnexal mass separate from the ovary ("sliding sign") with a gestational sac containing a yolk sac, or a mobile adnexal mass separate from the ovary with a gestational sac and fetal pole (with or without heartbeat) — NICE 1.4.17.
What is a "tubal ring" or "bagel sign" and what does it mean?+
It describes a mobile adnexal mass, separate from the ovary, with an empty gestational sac — a high-probability finding for tubal ectopic pregnancy (NICE 1.4.18), which still requires correlating other intrauterine and adnexal findings, clinical presentation, and serum hCG levels before concluding.
Does an empty uterus on ultrasound already confirm ectopic pregnancy?+
Not on its own. An empty uterus is a finding that suggests possible ectopic pregnancy (NICE 1.4.19), but before concluding it is necessary to consider other intrauterine and adnexal findings, clinical presentation, and serum hCG levels — see also the recommendations for PUL (pregnancy of unknown location).
How do you tell a pseudosac apart from a true, very early intrauterine sac?+
A very early intrauterine sac appears as an eccentric hypoechoic structure with the "double decidual sign" (gestational sac surrounded by two concentric echogenic rings in the endometrium). A pseudosac, on the other hand, is a central fluid collection in the uterine cavity, without that double ring.
Does free fluid in the pelvis always indicate an emergency?+
A moderate to large amount of free fluid in the peritoneal cavity or pouch of Douglas may represent hemoperitoneum (NICE 1.4.20) and should prompt consideration of intrauterine and adnexal findings, clinical presentation, and hCG before concluding — which is why it is flagged as an attention finding in the checklist.
What is heterotopic pregnancy and when should it be considered?+
It is the coexistence of an intrauterine pregnancy and an ectopic pregnancy. When performing an ultrasound (abdominal or transvaginal) in early pregnancy, the exam should include the uterus and adnexa specifically to assess this possibility (NICE 1.4.21).