Labor & Delivery

Stages and Phases of Labor

Labor

  • Regular and painful uterine contractions ➔ progressive dilation and effacement (softer and thinner) of cervix

    • Labor contractions are coordinated, with regular rhythm

      • Every 10mins (first stage) ➔ every 2-3 mins (second stage)

    • Braxton Hicks contractions (false labor) contractions are irregular ~2/hr, lasting <1min

Dilation (0cm ➔ 10cm)

  • Digital cervical examinations

    • At admission

    • q2-4hrs during first stage

    • q1-2hrs during second stage to evaluate descent

    • Before analgesia/anesthesia

    • Urge to push/fetal distress

First Stage: Onset of labor ➔ complete dilation

  • Bloody show: mucous plug dislodged ➔ blood tinged mucus

  • Spontaneous rupture of membrane ➔ watery discharge (arborization - fluid on slide resembles fern)

  • Latent phase: Gradual cervical change (0 ➔ ~4cm)

    • Lasts from 14-20hrs

  • Active phase (>4cm): Rapid cervical change (~1-2cm/hr)

    • Lasts ~1hr (parous) to 3hrs (nulliparous)

Second Stage: Complete dilation ➔ expulsion

    • Lasts ~15mins to 1hr

Third Stage: Fetal expulsion ➔ placental expulsion

  • 3 signs of placental separation

  1. Gush of blood

  2. Umbilical cord lengthening

  3. Anterior cephalad movement of fundus (becomes globular and firm)

  • ONLY PERFORM MANUAL TRACTION IF ALL 3 SIGNS PRESENT

Uterus should "feel" normal ~4-6wks after birth

APGAR

7-10 is normal

Taken at 1min AND 5mins after birth

Appearance

0: blue

1: blue extremities

2: pink

Pulse

0: no pulse

1: bradycardia

2: >100

Grimace (response to stimulation)

0: no response

1: grimace with stim

2: cries/pulls away

Activity

0: none/floppy

1: extremities flex

2: active

Respirations

0: apneic

1: labored/weak cry

2: normal/strong cry

Position and movement

  • Engagement: Biparietal diameter at or below inlet of pelvis

  • Station: presenting part to level of ischial spines (+ or - cm)

  • Fetal lie: Fetus longitude compared to maternal longitude

    • Longitudinal by 32-36wks aka vertex (head down)

      • Transverse lie ➔ ↑ M&M

    • External version procedure after US confirms lie and r/o placenta problems

      • Usually done after 37wks

  • Presentation: Presenting part of fetus (cephalic/breech)

  • Fetal position

    • Occiput anterior position: Occiput points to symphysis pubis (fetus face down)

      • Left occiput anterior (MC): Fetal back faces left

      • Right occiput anterior: Fetal back faces right

    • Occiput posterior position: Face to pubis symphysis (fetus faces up)

Fetal movements during normal delivery

Descent: Into pelvic inlet (where is presenting part to ischial spine) -5 station, 0 station (engagement)

Flexion: Fetus chin to chest

Internal rotation: Shoulders square off with widest part out (transverse to anterior-posterior)

Extension: Fetus pushes chin up to push out (+5 station)

External rotation: Turns head back to side to line up with shoulders (restitution)

Expulsion: Catch