Management of Pregnancy at 10 Weeks with Prior Painless Second-Trimester Loss at 18 Weeks
Serial transvaginal ultrasound monitoring starting at 14-16 weeks is the recommended approach, with ultrasound-indicated cerclage placement only if the cervix shortens to ≤25 mm before 24 weeks of gestation. 1
Why Serial Ultrasound is the Correct Answer
Your patient has a single prior painless second-trimester loss at 18 weeks, which is suggestive of cervical insufficiency but does not meet criteria for prophylactic (history-indicated) cerclage. Here's the evidence-based rationale:
History-Indicated Cerclage is NOT Appropriate
- History-indicated cerclage at 12-14 weeks should be reserved for patients with three or more second-trimester pregnancy losses or extreme premature deliveries without other identifiable causes. 2, 1
- Your patient has only ONE prior loss, which does not meet this threshold for prophylactic cerclage placement at an arbitrary gestational age. 1
- The American College of Obstetricians and Gynecologists specifically recommends against placing cerclage at predetermined gestational ages without objective cervical assessment. 1
The Optimal Management Strategy
- Begin serial transvaginal ultrasound assessment of cervical length starting at 14-16 weeks of gestation. 1
- Transvaginal ultrasound is the reference standard for cervical assessment, superior to clinical examination alone. 1
- Approximately 69% of high-risk women maintain cervical length >25 mm and do not require cerclage, making universal prophylactic cerclage inappropriate. 1
When to Intervene with Cerclage
- If cervical length measures ≤25 mm before 24 weeks of gestation, offer ultrasound-indicated cerclage placement. 1
- If cervical length is <10 mm, cerclage shows particular benefit, with decreased preterm birth at <35 weeks (39.5% vs 58.0%). 2, 1
- Continue monitoring cervical length through 24 weeks of gestation. 1
Additional Management Considerations
- Consider vaginal progesterone if cervical length shortens to ≤20 mm (GRADE 1A recommendation). 3, 1
- For cervical length 21-25 mm, vaginal progesterone may be considered based on shared decision-making (GRADE 1B). 3, 1
- After cerclage placement (if needed), adding vaginal progesterone 200 mg daily may reduce spontaneous preterm birth at <34 weeks (2.2% vs 18.4%). 2, 1
Critical Pitfalls to Avoid
- Do not place cerclage at 13 or 15 weeks without objective evidence of cervical shortening. 1 This represents outdated practice not supported by current evidence.
- Do not rely on clinical cervical examination alone—transvaginal ultrasound provides superior risk stratification. 1
- Reassurance alone is inadequate given the history of prior second-trimester loss, as this patient requires active surveillance. 1
Why This Approach is Superior
The serial ultrasound strategy allows you to identify the subset of patients who truly need intervention while avoiding unnecessary cerclage in the majority who will maintain adequate cervical length. This evidence-based approach balances intervention with surveillance, optimizing outcomes while minimizing procedural risks. 1, 4
Answer: D. Serial ultrasound for progress