Is a 35‑week pregnant patient with 1.5 cm cervical dilation, an uneffaced cervix, fetal station –4 and leaking fluid in the latent phase of labor?

Labor Phase Classification at 35 Weeks with Cervical Changes and Fluid Leakage

Yes, this patient is in the latent phase of labor (or possibly experiencing false labor/Braxton-Hicks contractions), not active labor. 1

Cervical Dilation Assessment

• A cervical dilation of 1.5 cm with an uneffaced cervix definitively places this patient in the latent phase of labor, as active labor requires ≥6 cm dilation according to current ACOG criteria. 1
• At 1.5 cm, the patient is in early latent phase where cervical change occurs slowly and gradually, with normal progression rates of 0.5-0.6 cm/hour. 2
• The threshold for active labor is 6 cm dilation (ACOG) or 5-6 cm (WHO/FIGO), meaning this patient is nowhere near the active phase transition. 1, 2

Fetal Station Evaluation

• The fetal station of –4 (head approximately 4 cm above the ischial spines) indicates the fetal head has not engaged in the pelvis, which is inconsistent with active labor. 1
• In true active labor, cervical dilation must be accompanied by fetal descent—the absence of descent at this station strongly suggests labor has not truly begun or is only in very early latent phase. 1
• This lack of engagement is a critical indicator that distinguishes latent from active labor, as active labor does not occur without concurrent fetal descent. 1

Clinical Classification

• This presentation is best classified as latent-phase labor or Braxton-Hicks (false) contractions rather than true active labor. 1
• The combination of minimal dilation (1.5 cm), uneffaced cervix, and high fetal station (–4) all point to either very early latent labor or prodromal labor patterns. 1, 2

Management Implications of Fluid Leakage at 35 Weeks

• The "leaking" fluid requires immediate evaluation to determine if this represents rupture of membranes, which would significantly alter management regardless of labor phase. 1
• At 35 weeks gestation (late preterm), decisions regarding tocolysis versus allowing delivery must balance neonatal morbidity risks against benefits of prolonging pregnancy. 1
• If membranes are intact and cervical length by transvaginal ultrasound is ≥30 mm, this predicts very low risk of delivery within 48 hours to 7 days. 1

Critical Management Pitfalls to Avoid

• Do not diagnose protracted or arrested labor at 1.5 cm dilation—labor abnormalities cannot be diagnosed before 6 cm, as patients below this threshold are presumed to be in latent phase. 3, 2
• Do not admit to labor and delivery based solely on 1.5 cm dilation unless there are maternal or fetal complications (such as confirmed rupture of membranes, bleeding, or fetal distress). 2
• Serial cervical examinations plotted over time are the only reliable method to determine if the patient is progressing normally through latent phase. 2

Monitoring Approach

• Verify the source of fluid leakage immediately (sterile speculum exam, nitrazine/ferning test, or ultrasound for amniotic fluid volume).
• If membranes are ruptured at 35 weeks, management shifts from labor assessment to preterm premature rupture of membranes protocols.
• If membranes are intact, the patient can be managed expectantly with outpatient monitoring unless contractions become regular and progressive or other complications arise.