5 Ps of Labor

5 Ps of Labor

• Powers (contractions):

  • Purpose: dilate cervix, aid in expulsion
  • Originate in the fundus
  • Measured by frequency and duration
  • Rest between contractions allows oxygen to fetus
  • Intensity: mild (<40 mmHg), moderate (40-70 mmHg), strong (>70 mmHg)
  • IUPC (intrauterine pressure catheter) can be used to measure intensity, but membranes must rupture first

• Passageway:

  • Maternal pelvis (gynecoid, anthropoid, platypelloid, android)
  • Maternal soft tissues (cervix) – cervix needs to be ripe
  • Effacement (thinning) vs dilation (opening)
  • Gynecoid pelvis is most common (50%)
  • Fetal head needs to rotate
  • Bishop score indicates likelihood of natural labor initiation

• Passenger:

  • Fetal attitude (flexion of legs and arms)
  • Fetal lie (position relative to mom's spine, longitudinal)
  • Fetal presentation (cephalic, breech, shoulder)
  • Fetal position (relationship of fetal part to maternal pelvis)
  • Positional relationships are crucial to vaginal delivery, especially shoulder

• Position (maternal pelvis position):

  • Station: placement of presenting part in pelvis (zero station = presenting part engages the ischial spines)
  • Direction (left or right, maternal side)
  • Presenting part (fetal head)

• Psyche:

  • Parity (number of pregnancies)
  • Age
  • Culture
  • Coping mechanisms
  • Emotional factors
  • Length of labor
  • Intensity of labor
  • Maternal positions
  • Fetal position

Nursing Assessment of Laboring Client

• Maternal Assessment:

  • Vital signs
  • Uterine activity
  • Bladder status and I&O
  • Bloody show/bleeding
  • Membrane status
  • Response to labor
  • Maternal discomfort
  • Cultural needs

• Fetal Assessment:

  • Fetal presentation and station
  • Fetal heart rate
  • Fetal gestation and growth
  • Maternal history
  • Allergies

Fetal Assessment During Labor (External and Internal EFM)

• Fetal heart tracing:
  • Baseline heart rate
  • Variable decelerations
  • Early decelerations (head compression)
    • "mirror image"
    • Pressure on fetal skull, nursing interventions are crucial
  • Late decelerations (placental insufficiency)
    • Indicates fetal hypoxia
  • Variable decelerations (cord compression)
    • Occurs during any time of contraction
    • Secondary to cord compression

FHR Categories

• Category I: normal, no intervention needed.
• Category II: indeterminate, continued evaluation needed.
• Category III: abnormal, fetus in danger, requires evaluation and intervention.

Initiation of Labor Factors

• Uterine stretching (release of prostaglandins)
• Oxytocin release
• Decrease in progesterone
• Increase in prostaglandin secretion
• Cortisol release (inhibiting progesterone and increasing prostaglandin)
• Placental aging

True vs False Labor

• True labor:
  • Regular contractions
  • Progressive changes
  • Discomfort begins in back and continues
• False labor:
  • Irregular contractions
  • Discomfort in lower abdomen
  • Contractions stop with activity/walking

Stages of Labor

• First stage:
  • Early (latent) labor
  • Active labor
  • Transition phase
• Second stage:
  • Descent and expulsion of fetus
  • Adds voluntary efforts
  • Overwhelming urge to push
  • Increase feeling of control
• Third stage:
  • Expulsion of placenta
  • Detachment 5-10 minutes after birth
• Fourth stage:
  • Postpartum period (first 4 hours after birth)
  • Assessing for hemorrhage
  • Assess for complications

Pain Management

• Tissue anoxia: tissue deprivation of oxygen
• Stretching (dilation) of cervix: stretching of the cervix causing pain
• Pressure on pelvic floor: Pressure on pelvic floor with contractions
• Nonpharmacological:
  • Cutaneous stimulation strategies (tactile, touch)
  • Sensory stimulation (distraction, comforting)
  • Cognitive strategies (relaxation techniques)
• Pharmacological:
  • Analgesia: partial relief of pain (IV, IM, inhalation)
  • Anesthesia: full loss of pain (may impact fetus)

Complications of Labor

• Preterm labor: labor before 37 weeks
• Dystocia: Difficult labor

Shoulder Dystocia

• Lack of fetal descent despite strong contractions; labor prolongs.
• Interventions: forceps, vacuum extraction

Cord Prolapse

• Obstetric emergency; umbilical cord descends alongside or in front of the presenting fetal part
• Intervention: Place mother in Trendelenburg position to take pressure off the cord

Fetal Circulation

• Fetal circulation can be reduced or completely cut-off in situations that place excessive pressure on the umbilical cord
• Place in Trendelenberg position if pressure can be reduced