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First Stage of Labor

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First Stage of Labor, Stage One of Labor, Labor Stages, Friedman Curve, Latent Phase of Labor, Active Phase of Labor

  • See Also
  1. Labor Dystocia
  2. Vaginal Delivery
  3. Cesarean Section
  4. Second Stage of Labor
  5. Third Stage of Labor
  • Definitions
  1. Spontaneous Labor
    1. Regular uterine contractions result in cervical dilation and effacement
  2. Premature Rupture of Membranes
    1. Amniotic membrane rupture before the onset of labor
    2. Spontaneous labor typically begins within 12 to 24 hours of membrane rupture
    3. Early Labor Induction is typically initiated within hours of PROM (except in preterm cases)
  • Stages
  • Three Stages of Labor
  1. Stage 1
    1. Divided into two phases (assuming regular contractions in both phases)
      1. Latent Phase (<6 cm cervical dilation)
      2. Active Phase (6 to 10 cm cervical dilation)
    2. Progresses until complete cervical dilation and effacement
    3. Expected progress is based on Friedman Curve
      1. Assumes regular, frequent palpable contractions
  2. Stage 2
    1. See Second Stage of Labor
    2. Starts with complete cervical dilation and effacement
    3. Ends with newborn delivery
  3. Stage 3
    1. See Third Stage of Labor
    2. Starts with newborn delivery
    3. Ends with delivery of the placenta and fetal membranes
  • Phase
  • Latent First Stage of Labor
  1. Latent Phase Definition
    1. Cervical dilation <6 cm and
    2. Regular contractions
  2. Normal Progress
    1. Nulliparous women
      1. Maximum normal duration <20 hours
    2. Multiparous women
      1. Maximum normal duration <14 hours
  3. Management
    1. Avoid hospitalization in latent labor (<4-5 cm dilated, <80% effaced, non-painful contractions)
      1. Exception: Maternal or Neonatal high risk conditions
    2. Maximize hydration
    3. Facilitate rest and supportive environment
    4. Consider latent phase sedation (e.g. Hydroxyzine)
    5. See Non-Pharmacologic Pain Control in Labor
  • Phase
  • Active First Stage of Labor
  1. Definition
    1. Cervical dilation >6 cm and
    2. Regular contractions
  2. Normal Progress
    1. Nulliparous women
      1. Cervical Dilation: >1.2 cm/hour
      2. Fetal Descent: >1 cm/hour
      3. Duration <8.6 hours
    2. Multiparous women
      1. Cervical Dilation: >1.5 cm/hour
      2. Fetal Descent: >2 cm/hour
      3. Duration <7.5 hours
  3. Management
    1. Progress
      1. See Prevention of Labor Dystocia
      2. See Labor Dystocia
      3. Consider Amniotomy
      4. Consider Active Management of Labor
        1. Oxytocin Augmentation
    2. Monitoring
      1. See Fetal Heart Tracing
      2. Avoid too frequent cervical examinations (dilation, effacement, Fetal Station)
        1. Focus on examinations that will change management (e.g. Labor Augmentation, Amniotomy)
        2. Frequent cervical exams increase the risk of Chorioamnionitis
    3. Labor Pain Management
      1. See Non-Pharmacologic Pain Control in Labor
      2. See Active Labor Anesthesia and Labor Analgesia
      3. See Labor Coaching
    4. Group B Streptococcus Prophylaxis
      1. See Group B Streptococcus Prophylaxis for indications
      2. GBS is screened universally in U.S. at 36 weeks gestation
      3. When indicated, GBS Prophylaxis is started in active labor or at PROM
        1. Continued GBS Prophylaxis through newborn delivery
    5. Less restrictive diet in the First Stage of Labor appears safe
      1. Does not appear to increase the aspiration risk, and may decrease First Stage of Labor duration
      2. Ciardulli (2017) Obstet Gynecol 129(3):473-80 +PMID: 28178059 [PubMed]
  • References
  1. LeFevre (2021) Am Fam Physician 103(2): 90-6 [PubMed]
  2. McKenna (2024) Am Fam Physician 109(6): 525-32 [PubMed]