Second Stage of Labor and Birth

Second Stage of Labor and Birth

• The second stage of labor begins with complete cervical dilation (10 cm) and ends with expulsion of the fetus.
• The transition between first and second stages may not be clearly defined clinically and physiologically.
• Physiologically, the second stage begins with the urge to push and ends with birth.
• The urge to push typically occurs when the presenting part of the fetus reaches +1 station.

Introduction

• Midwives create a supportive and safe environment during labor and birth, encouraging the natural processes for healthy outcomes.
• Midwives anticipate needs and monitor the assessed data for women and their support persons, while understanding the wide spectrum of normal and abnormal parameters.

Definition of Second-Stage Labor

• Anatomically, second-stage labor begins when the cervix is fully dilated and ends with fetal expulsion.
• The clinical and physiologic demarcation between first and second stages is often less distinct.
• Physiologically, the second stage encompasses the urge to bear down until the infant's birth.

Signs and Symptoms of Second-Stage Labor

• The most common symptom is the urge to push or bear down.
• Other signs include:
  • Fetal heart rate (FHR) located lower on the maternal abdomen.
  • Rectal bulging
  • Perineal bulging
  • Visible fetal head at the vaginal opening.
  • Increased bloody show
  • Variable decelerations in FHR pattern during pushing efforts.
• "The baby's coming!" is often a reliable sign of imminent birth.

Duration of Second-Stage Labor

• Friedman reported an average second-stage length of 46 minutes for first vaginal births and 14 minutes for subsequent births.
• Parameters for defining second-stage duration have changed due to epidural analgesia, affecting maternal bearing-down efforts.
• Women using epidural analgesia may have a prolonged second stage as pelvic/rectal sensation is decreased or absent, lessening the urge to bear down.

Factors Influencing Second-Stage Duration

• Parity
• Fetal position
• Epidural analgesia
• First-stage labor dystocia
• Uterine contraction activity
• Presence or absence of infection
• Effectiveness of maternal pushing efforts
• Pelvic architecture
• Birth weight
• Maternal weight
• Induction of labor
• Maternal fear or anxiety
• Maternal pain or discomfort
• Maternal history of sexual trauma

Maternal Complications Associated with Prolonged Second-Stage Labor

• Prolonged pushing (over 2-3 hours) increases risk of:
  • Intra-amniotic infection
  • Postpartum hemorrhage
  • Operative birth
  • Third- and fourth-degree lacerations
• Prolonged pushing can contribute to long-term dystocia.
• Multiparous women have an increased risk of shoulder dystocia during prolonged labor.
• Intra-amniotic infection can be both a cause and result of prolonged labor.

Fetal Complications Associated with Prolonged Second-Stage Labor

• Prolonged labor is linked to a slightly increased risk of:
  • 5-minute Apgar score less than 4
  • Neonatal sepsis
  • Admission to the Neonatal Intensive Care Unit (NICU)
  • Perinatal mortality
• The absolute risk of adverse outcomes is generally low.

Definition of Prolonged Second-Stage Labor

• Prolonged second-stage labor is defined as longer than 2 hours for primgravidas and longer than 1 hour for multigravidas.
• Specific thresholds exist for nulliparous/multiparous women with and without epidural analgesia.

Critical Elements of a Second-Stage Labor Consultation Note

• Subjective: Woman's description of labor experience (sensations, pushing effort).
• Objective Data: Labor status (contraction details, cervical dilation time, active pushing time), fetal status/position/station, maternal status.
• Assessment: Midwife's assessment of maternal/fetal progress (descent/rotation).
• Plan: Documentation of total second-stage labor time/active pushing time and the plan for continued/rest in pushing, reassessment details.

Second-stage Labor Abnormalities

• Prolonged duration
• Persistent Occiput Posterior Position
• Protracted descent
• Arrest of descent
• Failure of descent

Presenting Anterior/Posterior Fetal Skull Diameters

• Different diameters for anterior and posterior positions of the fetus' head.

Technique for Digital/Manual Rotation of Occiput Posterior Position

• Methods for aiding fetal rotation.

Midwifery Assessment During Second Stage Labor

• Maternal vital signs (BP, T, P, R) and well-being. Frequent checks, especially between contractions. Assess bladder frequently due to potential for compression. Assess hydration/nutrition. Evaluate pain levels and coping mechanisms. Assess fatigue. Assess maternal pushing efforts.
• Fetal well-being: Frequent fetal heart rate (FHR) monitoring. Evaluate FHR patterns in response to contractions and pushing. Monitor for any changes in FHR baseline or decelerations (e.g., variable decelerations). Assess fetal descent and rotation as evidenced during examination.
• Labor progress: Assess contraction frequency, duration, and intensity. Assess and document progress towards favorable outcome (descent/rotation/birth).