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
