Labor and Delivery

Labor
►    Regular, frequent, leading to progressive cervical effacement and dilatation
►    Braxton-Hicks contractions
    May be painful and regular, but usually are not
    Do not lead to cervical change
►    Labor diagnosis usually made in retrospect.
►    Cause of labor is unknown



Latent Phase Labor
►    <4 cm dilated
►    Contractions may or may not be painful
►    Dilate very slowly
►    Can talk or laugh through contractions
►    May last days or longer
►    May be treated with sedation, hydration, ambulation, rest, or pitocin


Active Phase Labor
►    At least 4 cm dilated
►    Regular, frequent, usually painful contractions
►    Dilate at least 1.2-1.5 cm/hr
►    Are not comfortable with talking or laughing during their contractions


Progress of Labor
►    Lasts about 12-14 hours (first baby)
►    Lasts about 6-8 hours (subsequent babies)
►    Considerable variation.
►    Effacement (thinning)
►    Dilatation (opening)
►    Descent (progress through the birth canal)


Descent
►    Fetal head descends through the birth canal
►    Defined relative to the ischial spines
►    0 station = top of head at the spines (fully engaged)
►    +2 station = 2 cm past (below) the ischial spines


Cardinal Movements of Labor
►    Engagement (0 Station)
►    Descent
►    Flexion (fetal head flexed against the chest)
►    Internal rotation (fetal head rotates from transverse to anterior
►    Extension (head extends with crowning)
►    External rotation (head returns to its’ transverse orientation)
►    Expulsion (shoulders and torso of the baby are delivered)


Watch a Delivery
Placental Separation
►    Signs of separation:
    Increased bleeding
    Lengthening of the cord
    Uterus rises, becoming globular instead of discoid
    Uterus enlarges, approaching the umbilicus
►    Normally separates within a few minutes after delivery


Initial Labor Management
►    Risk assessment
►    Contractions: frequency, duration, onset
►    Membranes: Ruptured, intact
►    Status of cervix: dilatation, effacement, station
►    Position of the fetus: vertex, transverse lie, breech
►    Fetal status: fetal heart rate, EFM


Cervix
►    Dilatation: How far has the cervix opened (in cm)
►    Effacement: How thin is the cervix (in cm or %)


Status of Membranes
►    Nitrazine paper turns blue in the presence of alkaline amniotic fluid (“nitrazine positive”)
►    Vaginal secretions are nitrazine negative (yellow) because of their acidity
►    Pooling of amniotic fluid in the vaginal vault is a reliable sign



Orientation of Fetus
►    Vertex, breech or transverse lie
►    Palpate vaginally
►    Leopold’s Maneuvers


Management of Early Labor
►    Ambulation OK with intact membranes
►    If in bed, lie on one side or the other…not flat on her back
►    Check vital signs every 4 hours
►    NPO except ice chips or small sips of water


Monitor the Fetal Heart
►    During early labor, for low risk patients, note the fetal heart rate every 1-2 hours.
►    During active labor, evaluate the fetal heart every 30 minutes
►    Normal FHR is 120-160 BPM
►    Persistent tachycardia (>160) or bradycardia (<120, particularly <100) is of concern


Electronic Fetal Monitors
►    Continuously records the instantaneous fetal heart rate and uterine contractions
►    Patterns are of clinical significance.
►    Use in high-risk patients.
►    Use in low-risk patients optional


Normal Patterns
►    Normal rate
►    Short term variability (3-5 BPM)
►    Long term variability (15 BPM above baseline, lasting 10-20 seconds or longer)
►    Contractions every 2-3 minutes, lasting about 60 seconds


Tachycardia
►    >160 BPM
►    Most are not suggestive of fetal jeopardy
►    Associated with:
    Fever, Chorioamnionitis
    Maternal hypothyroidism
    Drugs (tocolytics, etc.)
    Fetal hypoxia
    Fetal anemia
    Fetal arrythmia

Bradycardia
►    Sustained <120 BPM
►    Most are caused by increased in vagal tone
►    Mild bradycardia (80-90) with retention of variability is common during 2nd stage of labor
►    <80 BPM with loss of BTBV may indicate fetal distress


Late Decelerations
►    Repetive, non-remediable slowings of the fetal heartbeat toward the end of the contraction cycle
►    Reflect utero-placental insufficiency


Early Decelerations
►    Periodic slowing of the FHR, synchronized with contractions
►    Rarely more than 20-30 BPM below the baseline
►    Innocent
►    Associated with fetal head compression


Variable Decelerations
►    Variable in onset, duration and depth
►    May occur with contractions or between them
►    Sudden onset/recovery
►    Increased vagal tone, usually due to some degree of cord compression

Severe Variable Decelerations
►    Below 60 BPM for at least 60 seconds
►    If persistent, can be threatening to fetal well-being, with progressive acidosis


Prolonged Decelerations
►    Last > 60 seconds
►    Occur in isolation
►    Associated with:
    Maternal hypotension
    Epidural
    Paracervical block
    Tetanic contractions
    Umbilical cord prolapse

Pain Relief
►    Narcotics
►    Continuous Lumbar Epidural
►    Paracervical Block
►    50/50 nitrous/oxygen
►    Psychoprophylaxis (Lamaze breathing)
►    Hypnosis


Anesthesia During Delivery
►    Local
►    Pudendal Block
►    Epidural
►    Caudal
►    Spinal
►    50/50 nitrous/oxygen


Episiotomy
►    Avoids lacerations
►    Provides more room for obstetrical maneuvers
►    Shortens the 2nd Stage Labor
►    Midline associated with greater risk of rectal lacerations, but heals faster
►    Many women don’t need them.


Clamp and Cut the Cord
►    Clamp about an inch from the baby’s abdomen
►    Use any available instruments or usable material
►    Check the cord for 3-vessels, 2 small arteries and one larger vein


Inspect the Placenta
►    Make sure it is complete
►    Look for missing pieces
►    Look for malformations
►    Look for areas of adherent blood clot