Normal labour and delivery

Definition

• Uterine contractions leading to progressive dilation of the cervix
• Preterm before 37 weeks
• Post-term after 42 weeks

Physiology

• Estrogen-progesterone changes lead to coordinated uterine contractions
• Contractions soften the cervix, which dilates and thins

Clinical Manifestations

• Increased pelvic pressure
• Regular contractions
• Cramping
• Lower back ache
• Clear fluid leakage from vagina
• Increased urinary frequency

Assessment

• Leopold's maneuvers
  • First: palpate fundus with both hands to determine presenting part
  • Second: move down to identify the back and front to determine lie
  • Third: one-handed assessment of pelvis to determine engagement
  • Fourth: both hands to determine flexion of fetal neck (brow?)
• Contractions
  • Frequency
  • Duration
  • Intensity
• Cervix
  • Effacement
  • Dilation
  • Position
    • Posterior
    • Midposition
    • Anterior
• Membrane: vaginal exam
  • Intact or ruptured
• Fetus
  • Heart rate
  • Presenting part: Leopold's maneuvers and vaginal exam
  • Position: feel the sutures
    • Occiput posterior (OP)
    • Occiput anterior (OA), etc
  • Lie: Leopold's maneuvers
    • Longitudinal: normal
    • Oblique
    • Transverse
      • Back down: requires a classical vertical Caesarian section
      • Back up: can have a horizontal uterine incision
  • Engagement: fetal head descended into pelvis
  • Station: relationship between presenting part and pelvis
    • Ranges from -5 to +5 cm in relation to 0 station
    • 0 station is the ischial spine
    • Poor inter-rater reliability
• Bishop score
  • Predicts the success of induction of labour
  • Components: NEEDS CORRECTION
    • Cervical dilatation: closed, 1-2, 3-4, >4
    • Cervical effacement: 0-30%, 40-50%, 60-70%, 80+%
    • Cervical consistency: firm, medium, soft
    • Cervical position: posterior, midposition, anterior
    • Fetal station: -3, -2, -1, +1 or +2
  • Each component scored from 0 to 2 or 3, to a maximum of 13
  • Add one point for each of
    • Preeclampsia
    • Each previous vaginal delivery
  • Subtract one point for each of
    • Post dates
    • Preterm

Stages of Labour

• Stage I: cervical dilatation
  • Latent
    • Starts with any contractions leading to cervical dilatation
    • Ends around 4-5 cm dilatation
  • Active
    • Starts when cervical dilatation reaches 4-5 cm
    • Ends at complete dilatation of the cervix
• Stage II: delivery of the fetus
  • Cardinal movements
    • Engagement
    • Descent
    • Flexion
    • Internal rotation
    • Extension
    • External rotation
    • Expulsion
  • Lasts up to 1h in primiparous, 1/2h in multiparous
• Stage III: delivery of the placenta
  • Lasts up to 1/2h
• Stage IV: recovery

Management

• Management depends on stage
• Ask patient to come to hospital when contractions occur every five minutes, lasting at least one minute, ongoing for at least one hour
• Stage I
  • Regularly monitor cervical dilatation, fetal station, fetal heart rate, and frequency of contractions
  • Increase frequency of monitoring as labour progresses
  • Fetal heart rate monitoring q1-2h during latent and q30min during active phase
  • Ambulation, lying on side
  • Vitals q4h or q1h if concerns exist
  • If risk of operative delivery: maintain NPO when active labour
  • If GBS positive: GBS prophylaxis
• Stage II
  • Position
  • Pushing
  • Control expulsion
  • Clamp cord (delayed)
• Stage III
  • Position fingers below uterus to prevent uterine inversion
  • Gentle cord traction
  • Watch for signs of placental detachment
    • Apparent cord lengthening
    • Gush of blood
    • Uterus firming and balling
  • If no progress, can attempt fundal massage or oxytocin
  • Oxytocin 10 IU IV or misoprostol 600mcg po once, to decrease risk of postpartum hemorrhage
• Stage IV
  • Monitor for hemorrhage