5 Ps of Labor

Study Notes

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

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 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

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

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

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

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)

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 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