Transvaginal · First trimester
What do you notice? Commit in the Ultrasound Lab.
Gestational context
Trimester 1
booking
12w
anatomy
24w
28w
36w
term
Recognition
- Risk factors: prior ectopic, tubal surgery or infection, IUD in place (the pregnancy that occurs is more often ectopic), assisted reproduction, smoking. Half have no risk factor.
- Presentation: amenorrhoea, unilateral pain, light bleeding; shoulder-tip pain, syncope and shock with rupture.
- Transvaginal ultrasound: an empty uterus with an adnexal mass (blob or bagel sign) or free fluid. A pseudosac is central, without a yolk sac.
- Pregnancy of unknown location: positive test, nothing seen in the uterus or adnexa. Serial hCG at 48 hours: a rise of at least 35 to 50 percent suggests a viable intrauterine pregnancy not yet visible; a fall suggests a failing pregnancy; a plateau suggests ectopic. Above the discriminatory level (about 1500 to 3500 IU/L depending on the unit) an intrauterine pregnancy should be visible.
Tubal ectopic pregnancy (blob sign) in a patient with an IUD
Transvaginal, First trimester. An inhomogeneous mass adjacent to, and moving separately from, the ovary: the blob sign.
Open in the Ultrasound LabHaemoperitoneum from a ruptured ectopic pregnancy
Right upper quadrant, coronal (FAST view), First trimester. Anechoic fluid in the hepatorenal recess (Morison's pouch).
Open in the Ultrasound LabIntrauterine pregnancy confirmed by a yolk sac
Transvaginal, About 4+5 weeks (19 days post-conception). A 4 mm intrauterine sac with an echogenic rim.
Open in the Ultrasound LabManagement
- Anti-D for Rh-negative patients.
- Counsel on the higher risk of recurrence and the need for an early scan in the next pregnancy.
| Option | When | Notes |
|---|---|---|
| Expectant | Falling hCG under about 1500, minimal symptoms, reliable follow-up | Serial hCG until negative |
| Methotrexate | Unruptured, hCG under about 5000, no cardiac activity, mass under 3.5 to 4 cm, normal liver and renal function, able to follow up | Single intramuscular dose; hCG on days 4 and 7 should fall by 15 percent; avoid NSAIDs, alcohol, folate, intercourse; pain in the first days is common but must be assessed |
| Surgery | Ruptured or unstable, contraindications to methotrexate, or patient choice | Laparoscopic salpingectomy (preferred with a healthy contralateral tube) or salpingotomy |
Check
Positive test, 6 weeks by dates, mild pain, hCG 900, empty uterus and no adnexal mass. What is the correct plan?
On the modelFallopian tubesOvariesCervix