Chapter 16

Chapter 16: Labor and Delivery

Delivery Venue Options

Hospitals:
- Most births occur in hospitals.
- Access to key personnel, necessary equipment, pain control options, and emergency services.
Home births:
- Popular among those with negative hospital experiences.
- Patients often feel more comfortable, empowered, and in control at home.
Birthing centers:
  - Freestanding facilities not located within a hospital.
  - Primarily attended by midwives.
  - Designed for patients with low-risk pregnancies.
  - Must have transfer agreements with local hospitals for emergencies.

Five Ps of Labor

Labor consists of five components, termed the five Ps.
  - Dysfunction in any of these components can result in complications requiring intervention.
  - The five Ps include:
    1. Power: Refers to uterine contractions and pushing efforts.
    2. Passageway: Anatomy of the patient’s bony pelvis and soft tissues.
    3. Passenger: The fetus.
    4. Psyche: The patient’s state of mind.
    5. Position: The position of the patient during labor.

Five Ps of Labor: Power

Primary Powers:
  - Involuntary uterine contractions occurring in the upper two-thirds of the uterus.
  - Apply pressure to the fetus, causing cervical dilation and effacement.
  - Factors influencing power include contraction frequency, duration, and intensity.
  - Oxytocin can be administered to enhance contraction power.
Secondary Powers:
- Voluntary maternal actions like pushing that occur after the cervix is fully dilated.
- Effective pushing needs to coincide with contractions and may require coaching from nursing staff.

Five Ps of Labor: Passageway

The passageway is primarily dependent on:
  - Pelvic Shape:
    - Gynecoid pelvis shape offers the most favorable passageway for delivery.
  - Soft Tissue Stretchability:
    - Soft tissue usually does not impede fetal passage unless there is scarring from past surgeries.
  - Pelvic Floor Muscles:
    - Assist in fetal orientation and movement through cardinal movements during delivery.
  - Fetal Station:
    - Relation between the fetal presenting part and the pelvis.
    - A zero station indicates the presenting part is at the level of the ischial spines.

Five Ps of Labor: Passenger

The important factors involving the fetus during labor include:
  1. Fetal Head Size: Largest part of the fetus.
  2. Fetal Presentation: Refers to the part of the fetus entering the pelvis first (usually cephalic presentation).
  3. Fetal Attitude: Position of fetal body parts in relation to each other.
  4. Fetal Lie: Orientation of the fetus's body to the mother's body (e.g., longitudinal, transverse).
  5. Fetal Position: Relationship of the presenting part to the maternal pelvis (e.g., occiput, sacrum).
Breech Presentation Types:
  - Frank Breech: Buttocks first with legs extended.
  - Complete Breech: Buttocks first with legs flexed.
  - Single Footling Breech: One foot first into the pelvis.
  - Double Footling Breech: Both feet first into the pelvis.

Five Ps of Labor: Psyche

A patient’s psychological state significantly influences labor outcomes.
Factors that may slow labor include:
  - Anxiety
  - Stress
  - Fear
  - Pain Tolerance
Relaxation can enhance labor progress.

Five Ps of Labor: Position

Optimal Labor Position:
  - Upright positions tend to enhance contraction effectiveness.
  - Gravity aids successful labor and delivery.
  - Ideally, the pelvis is at a sharp flex when squatting or in similar positions.
  - Movement into comfortable positions correlates with better outcomes.
  - The lithotomy position, frequently used during birth, may have evolved for provider convenience.

Signs of Labor

Mechanisms triggering labor are not completely understood, but several signs indicate impending labor:
  - Regular contractions
  - Presence of bloody show (mucus plug with blood)
  - Lightening: The fetus descends into the birth canal, potentially occurring about two weeks before labor starts for first-time mothers.
  - Nesting impulse: Increased energy toward preparing for birth.
  - Gastrointestinal distress: Including heartburn, nausea, or diarrhea.
  - Weight Loss: Of 1 to 3 lb before labor onset.
  - Labor is confirmed by cervical change (dilation and effacement).

Stages and Phases of Labor

Labor is categorized into four stages:
  1. First Stage: Dilation and effacement of cervix.
     - Latent phase: 0 to 6 cm dilation.
     - Active phase: 6 to 10 cm dilation.
     - Transition phase: 8 to 10 cm dilation.
  2. Second Stage: Begins with complete cervical dilation and ends with the birth of the baby.
  3. Third Stage: Starts with the birth of the baby and ends with placenta delivery.
  4. Fourth Stage: Begins after placenta delivery and lasts until the patient is clinically stable or for about 4 hours.
First Stage Characteristics:
  - Latent Phase
    - Longest phase; excitement can be high; contractions resemble menstrual cramps and are mild.
  - Active Phase
    - Increased focus and anxiety; regular and painful contractions that are moderately strong.
  - Transition Phase
    - Strong and closely spaced contractions; patient may feel out of control, irritable, or exceptionally dependent.
Second Stage Characteristics:
- Pushing is often delayed until the urge is felt; duration ranges from 20 minutes to 2 hours.
Cardinal Movements during second stage include:
  - Engagement: Fetal head at the ischial spines.
  - Descent: Moving past the ischial spines.
  - Flexion: Fetal chin touches chest.
  - Internal Rotation: Fetal head rotates toward the anterior.
  - Extension: Fetal chin rises off chest and neck arches as the head is delivered.
  - External Rotation (restitution): Head delivers, rotates again for shoulder positioning.
  - Expulsion: Body of the fetus is born.
Third Stage Description:
  - Completion occurs 5 to 30 minutes after birth.
  - Uterine contractions help expel the placenta and reduce maternal bleeding by constricting blood vessels.
  - Failure to contract leads to uterine atony, a primary cause of postpartum hemorrhage.
Fourth Stage Activities:
- Nurse must assess uterine positioning, check vaginal bleeding and vital signs, administer pain relief, and support skin-to-skin contact and breastfeeding.

Nursing Care During Labor

Nursing actions based on institutional policies may include:
  - Initiating an IV line (typically 18 gauge).
  - Performing laboratory assessments (blood and urine samples).
  - Continuous or intermittent monitoring of vital signs.
  - Provide support to the laboring patient, including education and pain management.
  - Encourage voiding every two hours for bladder health and labor progress.

Fetal Monitoring

Purpose: Assessment of fetal heart rate (FHR) for fetal compromise.
- Normal Pattern: Correlates to positive neonatal outcomes.
- Abnormal Pattern: Correlates to hypoxemia, potentially leading to hypoxia.
Monitoring Types:
- Intermittent Monitoring: Includes fetal heart rate assessment every 15-30 minutes during active labor and every 5-15 minutes during the second stage.
- Continuous Monitoring: Common in the US, involves more frequent evaluations for high-risk patients.
FHR Characteristics:
  - The baseline heart rate is assessed over a 10-minute period, normally between 110 and 160 bpm.
  - Variability: Fluctuations in baseline rate; moderate variability is 6 to 25 bpm over 10 minutes.
  - Accelerations: Increase in baseline by 15 bpm lasting at least 15 seconds in a term fetus.
  - Decelerations: Decreases from the baseline, with different classifications based on cause:
    - Late Decelerations: Indicative of poor placental perfusion.
    - Variable Decelerations: Caused by cord compression.
    - Early Decelerations: Benign response to head compression during contractions.
    - Prolonged Decelerations: Defined as lasting 2 to 10 minutes.
Interventions for Abnormal Patterns:
  - Position changes.
  - Discontinuation of oxytocin.
  - Administration of oxygen 8-10 L via nonrebreather mask.
  - Correction of maternal hypotension.
  - Notification of the attending provider.

Labor Pain

Pain is a subjective experience influenced by various factors:
- Anxiety, previous experiences, support systems, and fatigue from labor.
- Manifestations include localized pain during contractions, with continuous pain in the low back indicating possible fetal positioning or issues such as placental abruption.

Labor Pain Management

Pharmacological Management:
  - Opioids:
    - Fentanyl: Short-acting, may cause respiratory depression in both mother and neonate.
    - Mixed opioid agonist/antagonists: Not recommended for opioid-dependent patients.
      - Examples:
        - Nalbuphine (Nubain): Lasts 3-6 hours.
        - Butorphanol (Stadol): Lasts 3-4 hours.
  - Nitrous Oxide: Self-administered gas; side effects include nausea and lightheadedness.
Nonpharmacological Management:
- Techniques include focused breathing, hypnotherapy, position adjustments, cutaneous stimulation, aromatherapy, music, and counter pressure.

Assessment Questions in Labor

Question on Oxytocin:
- If contractions are not frequent or intense, the expected order would likely be
- B. Oxytocin to augment labor.
Transition Phase Query:
- For increased agitation and contraction intensity with cervix at 6 cm, the nurse should check for transition phase:
- A. Check cervix for transition phase.
Interpretation of FHR Strip:
- A tracing with baseline heart rate of 130, moderate variability and contractions every 3 minutes indicates:
- A. Category I FHR tracing, no interventions required.
True/False Statement:
- Nonpharmacological pain management techniques should be limited to the latent phase of labor.
- Answer: False; effective throughout labor.