Notes on Labor & Birth Processes
Overview of the 5 P's
- Passenger: Fetus & Placenta
- Passageway: Birth canal
- Position: Position of the mother
- Powers: Contractions
- Psychology: Emotional response
Passenger: Fetus & Placenta
- Fetal Head Size & Fontanels
- Anterior Fontanel: Diamond-shaped, ossifies in 12-18 months
- Posterior Fontanel: Triangle-shaped, closes in 8-12 weeks
- Molding: Shaping of fetal skull to fit through birth canal
- Fetal Presentation
- Part of fetus entering pelvic inlet first
- Fetal Lie
- Longitudinal/Vertical: Parallel to mother’s spine
- Transverse/Horizontal/Oblique: Right angle to mother's spine
- Transverse: Vaginal birth not possible
Types of Breech
- Cephalic (Most Common)
- Head first, presenting part: occipital
- Breech
- Buttocks or feet first, presenting part: sacrum
- Shoulder
- Shoulder first, presenting part: scapula
Passageway: Birth Canal
- Fetal Attitude: General flexion, important for birth
- Pelvis Types
- Gynecoid: Most common, classic female type
- Android: Resembles male pelvis
- Anthropoid: Oval-shaped, wider anteroposterior diameter
- Platypelloid: Flat pelvis, least common
- Fetal Station: Position in pelvis, measured in cm
- Engagement: Station zero, baby engaged
Position
- Upright, all fours, lithotomy, and lateral positions
- Frequent position changes help relieve fatigue, increase comfort, and improve circulation
Powers
- Primary Powers
- Involuntary uterine contractions
- Mark start of labor
- Secondary Powers
- Aid in pushing once the cervix is dilated
- Ferguson Reflex: Oxytocin release triggers urge to push
- Effacement
- Shortening and thinning of cervix, expressed in %
- Cervix typically 2-3 cm long, 1 cm thick
- Dilation
- Gradual widening of cervical opening, measured in cm
- Full dilation at 10 cm
Psychology: Emotional Response
- Anxiety increases pain perception and medication need
- Considerations include social support, past experiences, and knowledge
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