What is the most appropriate management for a 28‑week pregnant woman with vaginal discharge, cramping, and a history of prior pregnancy loss or preterm birth?

Management of 28-Week Pregnant Woman with Vaginal Discharge, Cramping, and History of Pregnancy Loss/Preterm Birth

The best management is option 2: immediate evaluation with transvaginal cervical length assessment, followed by vaginal progesterone if cervical shortening is detected, combined with close monitoring for signs of preterm labor or infection. 1

Immediate Assessment Required

This patient requires urgent evaluation, not simple reassurance to return only if pain worsens. At 28 weeks with cramping and vaginal discharge in the context of prior pregnancy loss or preterm birth, she is at significant risk for:

• Preterm labor - Women with prior pregnancy loss have 1.6-fold increased odds of preterm birth 2
• Cervical insufficiency - May present with cramping and discharge 1
• Intraamniotic infection - Can present without fever, especially at earlier gestational ages 3
• Preterm premature rupture of membranes (PPROM) - History of pregnancy loss increases this risk 4

Critical First Steps

Transvaginal Cervical Length Assessment

• Perform transvaginal ultrasound to measure cervical length immediately - this is the gold standard for assessing preterm birth risk 1
• If cervical length is ≤20 mm at <24 weeks, vaginal progesterone (90 mg gel or 200 mg suppository daily) reduces preterm birth risk (GRADE 1A recommendation) 1
• If cervical length is 21-25 mm, vaginal progesterone should be considered based on shared decision-making (GRADE 1B recommendation) 1

Rule Out Active Labor and Membrane Rupture

• Perform sterile speculum examination to assess for cervical dilation, membrane rupture, and purulent discharge 1, 3
• Assess for signs of intraamniotic infection: maternal fever ≥38°C, maternal tachycardia, uterine tenderness, purulent or foul-smelling discharge, fetal tachycardia 3
• Fetal heart rate monitoring to assess fetal well-being and identify fetal tachycardia suggesting infection 1

Why Each Option Is Right or Wrong

Option 1: Exercise for Strength Muscle - INCORRECT

• No evidence supports exercise as intervention for threatened preterm birth 1
• Activity restriction and bed rest have no proven benefit and may cause harm (moderate strength of evidence) 5
• This completely misses the urgent need for assessment

Option 2: Monitor and Return if Severe Pain - PARTIALLY CORRECT BUT INCOMPLETE

• This is the framework of the correct answer, but monitoring must be active and immediate, not passive waiting at home
• She needs evaluation NOW, not instructions to wait for worsening symptoms 1, 3
• Infection can progress rapidly without obvious symptoms, and intraamniotic infection may present without fever 3

Option 3: Give Progesterone - CONDITIONALLY CORRECT

• Progesterone is indicated ONLY if cervical shortening is documented 1
• For women with prior spontaneous preterm birth, 17-alpha-hydroxyprogesterone caproate (17P) 250 mg IM weekly from 16-20 weeks until 36 weeks should have already been started 1, 5
• If she's not already on 17P and has a history of prior spontaneous preterm birth, this should be initiated 5
• However, progesterone has NO proven efficacy for symptomatic preterm labor (GRADE: no evidence of effectiveness) 1
• Vaginal progesterone is specifically indicated for asymptomatic women with short cervix discovered on screening, not for symptomatic patients 1

Optimal Management Algorithm

Step 1: Immediate Triage (Today)

1. Transvaginal cervical length measurement using standardized technique 1
2. Sterile speculum examination - assess for dilation, membrane rupture, discharge character 1
3. Fetal monitoring - continuous initially, then per protocol 1
4. Maternal vital signs - temperature, heart rate, blood pressure 3

Step 2: Risk Stratification Based on Findings

If cervical length <25 mm and asymptomatic:

• Start vaginal progesterone 90 mg gel or 200 mg suppository daily until 36 weeks 1
• Consider cerclage if cervical length ≤25 mm and <24 weeks gestation with prior spontaneous preterm birth 5

If signs of preterm labor (regular contractions with cervical change):

• Admit for observation and monitoring 1
• Consider tocolysis if appropriate gestational age and no contraindications 1
• Administer corticosteroids for fetal lung maturity if 24-34 weeks 3
• Magnesium sulfate for neuroprotection if <32 weeks 3

If signs of infection:

• Immediate delivery planning regardless of gestational age 3
• Broad-spectrum antibiotics 3

If membrane rupture confirmed:

• Admit for expectant management with antibiotics if <34 weeks 3
• Monitor closely for infection, abruption, fetal compromise 3

Step 3: Ongoing Management

• Serial cervical length assessments every 2-4 weeks from 16-24 weeks for women with prior spontaneous preterm birth 5
• Weekly outpatient visits if high-risk features identified 3
• Patient education on warning signs: increased discharge, bleeding, cramping, fever, decreased fetal movement 3

Critical Pitfalls to Avoid

• Do not delay evaluation - "wait and see" approach risks missing cervical insufficiency, infection, or preterm labor 3
• Do not prescribe progesterone empirically without cervical length assessment - it has no proven benefit for symptomatic patients 1
• Do not rely solely on maternal fever to diagnose infection - intraamniotic infection can present without fever, especially at earlier gestational ages 3
• Do not miss the opportunity for 17P if not already started - if she has documented prior spontaneous preterm birth and is not yet on 17P, this should be initiated (though at 28 weeks, the window for maximum benefit has passed) 5

Context: Her History Matters

The distinction between "pregnancy loss" and "preterm labor" in her history is clinically important:

• If prior spontaneous preterm birth: 50% risk of recurrence, with 30% delivering <34 weeks 1, 5
• If prior second-trimester loss: 4.5-fold increased odds of preterm birth in subsequent pregnancy 6
• If prior PPROM at <24 weeks: 50% recurrence risk, 17% risk of delivery <24 weeks 1, 5

All of these scenarios warrant the immediate evaluation described above, making option 2 (with proper implementation) the correct answer, while option 3 (progesterone) is only appropriate after cervical shortening is documented.