What is the management for a patient with a cervix 1 cm dilated and a negative ActiPartus (Actim Partus) test?

Management of a Patient with Cervix 1 cm Dilated and Negative ActiPartus Test

For a patient with a cervix 1 cm dilated and a negative ActiPartus test, expectant management with close monitoring is recommended, as this finding alone does not indicate active labor or high imminent risk of preterm birth.

Understanding the Clinical Significance

Cervical Dilation Assessment

• 1 cm cervical dilation can represent either:
  • Early latent phase of labor in a term pregnancy
  • Incidental finding in a preterm pregnancy
  • Possible cervical insufficiency if preterm

ActiPartus (Actim Partus) Test Interpretation

• Negative ActiPartus test indicates low levels of phosphorylated insulin-like growth factor binding protein-1 (phIGFBP-1)
• This suggests a low likelihood of delivery within the next 7-14 days
• The negative predictive value for this test exceeds 92% 1

Management Algorithm

For Term Pregnancies (≥37 weeks)

1. Assess for signs of active labor

   • Evaluate contraction pattern (frequency, intensity, duration)
   • 1 cm dilation alone likely represents early latent phase
   • Without regular painful contractions, patient is not in active labor 2

2. Management approach

   • If no regular contractions: Discharge home with precautions
   • If mild contractions: Consider observation for 2-4 hours to assess progression
   • Active labor begins with cervical dilation rate change, not at a specific dilation 2

For Preterm Pregnancies (<37 weeks)

1. Risk assessment

   • Even with negative ActiPartus, 1 cm dilation at preterm gestation carries risk
   • 20% risk of delivery <32 weeks and 38% risk <35 weeks despite minimal dilation 3

2. Management options based on gestational age:

   • <24 weeks: Consider cervical cerclage evaluation

     • Physical examination-indicated cerclage may be beneficial
     • Patients with 1-2.5 cm dilation who receive cerclage have outcomes similar to those with closed cervix 4

   • 24-34 weeks:

     • Administer antenatal corticosteroids if high risk of delivery within 7 days
     • Consider tocolysis if showing signs of preterm labor
     • Serial cervical length monitoring

   • >34 weeks:

     • Expectant management with close follow-up
     • No tocolysis indicated at this gestational age

Important Clinical Considerations

Factors That May Alter Management

• History of previous preterm birth: Increases risk significantly
• Cervical length on ultrasound: If <25mm, consider additional interventions
• Presence of contractions: Even with negative ActiPartus, regular contractions warrant closer monitoring
• Maternal symptoms: Pelvic pressure, increased discharge, or backache

Pitfalls to Avoid

1. Misdiagnosing active labor

   • 1 cm dilation alone is not diagnostic of active labor
   • Active phase begins with change in dilation rate, not at a specific dilation 2
   • Avoid unnecessary interventions for patients still in latent phase

2. Overlooking cervical insufficiency

   • In preterm patients, 1 cm dilation may represent early cervical insufficiency
   • Consider digital examination when cervical length <15 mm on ultrasound, as 30-70% may have cervical dilation 2

3. Inappropriate oxytocin use

   • Oxytocin should not be administered if:
     • Patient is not in established active labor
     • There is suspicion of cephalopelvic disproportion
     • Fetal distress is present 5

Follow-up Recommendations

• Schedule follow-up within 1 week for preterm patients
• Instruct patient to return for increasing contractions, rupture of membranes, bleeding, or decreased fetal movement
• Consider serial transvaginal ultrasound for cervical length monitoring in preterm patients

Remember that while a negative ActiPartus test is reassuring, the finding of 1 cm cervical dilation still warrants appropriate clinical vigilance, especially in the preterm population.