In a 10‑week pregnant woman with a history of painless second‑trimester loss at 18 weeks, what is the recommended management?

Management of Subsequent Pregnancy After Prior Painless Second-Trimester Loss

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 (Option D)

This patient has one prior painless second-trimester loss at 18 weeks, which represents a classic presentation of possible cervical insufficiency. However, a single loss does not meet criteria for prophylactic (history-indicated) cerclage. 1, 2

The Evidence-Based Algorithm

Step 1: Begin serial cervical length monitoring

• Start transvaginal ultrasound assessment at 14-16 weeks of gestation 1
• Continue monitoring through 24 weeks 1
• Approximately 69% of high-risk women maintain cervical length >25 mm and never require cerclage 1

Step 2: Intervene based on objective cervical shortening

• If cervical length measures ≤25 mm before 24 weeks: offer ultrasound-indicated cerclage 1
• If cervical length is ≤20 mm: prescribe vaginal progesterone 200 mg daily (GRADE 1A recommendation) 1
• If cervical length is 21-25 mm: consider vaginal progesterone through shared decision-making (GRADE 1B recommendation) 1
• If cervical length is <10 mm: cerclage shows particular benefit, with decreased preterm birth at <35 weeks (39.5% vs 58.0%) 1, 2

Why the Other Options Are Incorrect

Option A (Reassurance) is inadequate:

• This patient has a documented history of painless second-trimester loss, placing her at increased risk for recurrence 3
• Simply reassuring without objective monitoring ignores established risk factors 1

Option B (Cerclage at 13 weeks) is not indicated:

• History-indicated cerclage at 12-14 weeks should be reserved for patients with three or more second-trimester pregnancy losses or extreme premature deliveries 1, 2
• This patient has only one prior loss, which does not meet threshold for prophylactic cerclage 1
• Placing cerclage at arbitrary gestational ages without objective cervical assessment is explicitly discouraged 1

Option C (Cerclage at 15 weeks) is similarly not indicated:

• The same reasoning applies—cerclage should not be placed at predetermined gestational ages without documented cervical shortening 1
• Cerclage placement must be guided by objective cervical shortening, not performed prophylactically 1

Critical Distinction: Cervical Insufficiency vs. Short Cervix

This case illustrates the important difference between these two entities:

• Cervical insufficiency is a clinical diagnosis based on history of painless cervical dilation leading to second-trimester loss 3
• Short cervix is an ultrasound finding (≤25 mm) that predicts preterm birth risk 3
• Most patients with short cervix do not have classic historical features of cervical insufficiency 3

Additional Management Considerations

If cerclage becomes indicated during monitoring:

• Consider adding vaginal progesterone 200 mg daily after cerclage placement, which may reduce spontaneous preterm birth at <34 weeks (2.2% vs 18.4%) and <37 weeks (9.1% vs 29.7%) 1, 2

Avoid these common pitfalls:

• Do not place cerclage based solely on history of one prior loss without objective cervical assessment 1
• Clinical cervical examination alone is insufficient—transvaginal ultrasound provides superior risk stratification 1
• Do not use 17-alpha hydroxyprogesterone caproate for short cervix treatment (GRADE 1B recommendation against) 4, 1
• Do not place cervical pessary due to conflicting trial data and recent safety signals (GRADE 1B recommendation against) 4, 1

Activity recommendations:

• Routine daily activities and light upper-body resistance exercise are permitted 1
• Avoid moderate-to-vigorous physical activity 1
• Bed rest is explicitly not recommended and should be avoided 1