STAGES OF LABOR
FIRST STAGE
Latent phase – Cervical effacement and early dilatation
Primip – 6-18hr
Multip – 2-10hr
Active phase – Rapid cervical dilatation
Primip – 1cm/hr
Multip – 1.cm/hr
Friedman Curve
Abnormalities of labor
Prolonged Latent Phase
Protraction disorder of the active phase (dilatation)
Protraction disorder of descent
Arrest of dilatation
Arrest of descent
SECOND STAGE (pushing)
Primip – 30min – 3 hr, multip – 5 –30 min
Mechanisms of Labor
Descent – uterine contractions, maternal pushing, gravity
Flexion – baby’s chin to chest
Internal Rotation – Fetal head from transverse/oblique to occiput anterior
Extension – Vaginal outlet is upward and forward
Crowning – largest diameter of fetal head encircled by vulvar ring
External Rotation – delivered head returns to original position to align with back and
shoulders
Expulsion – anterior shoulder delivers under symphysis
THIRD STAGE
Delivery of the placenta – avg 2 –10min
Signs of placental seperation
1) Fresh show of blood
2) Umbilical cord lengthens
3) Fundus of uterus rises up
4) Uterus becomes firm and globular
Check for lacerations:
First degree –vaginal epithelium or perineal skin
Second degree – extends into subepithelial tissues or perineum with or without
involvement of muscles of the perineal body
Third degree – involvement of the anal sphincter
Fourth degree – involvement of the rectal mucosa
FOURTH STAGE
The hour immediately following delivery
Follow vitals and any signs of postpartum hemorrhage
INDUCTION OF LABOR – labor initiated by artificial means
AUGMENTATION OF LABOR – stimulation of labor after it has begun spontaneously
Indications – Maternal or Fetoplacental
Bishop Score–
Cervix
Position
Consistency
Effacement
Dilatation
Fetal Head
Station
0
post
Firm
0-30
0
1
mid
medium
40-50
1-2
2
anterior
Soft
60-70
3-4
3
=/> 80
>/= 5
-3
-2
-1
+1
High score 9-13 High likelihood of vaginal delivery
Low score <5 decreased likelihood of success (65-80%)
Cervical Ripening – mechanical +/- pharmacological
Intracervical dilators – Foley catheter, Laminaria
Prostaglandin E gel or vaginal insert, new – misoprostol (Cytotec)
Oxytocin – Identical to natural pituitary peptide
Amniotomy
ACTIVE MANAGEMENT OF LABOR
1) Nulliparous – spontaneous labor, singleton pregnancy, cephalic
2) Prenatal education classes
3) Constant attendance in labor with labor nurse specialist/midwife
4) Peer review of all c-sections
5) Not admitted without clear diagnosis of labor
Regular/painful contractions with one of the following:
complete cervical effacement, rupture of membranes, bloody show
6) Amniotomy upon admission
7) Regular exams for progress
8) Oxytocin if <1cm/hr or no descent for an hour
DELIVERY
Position, prep and drape
Crowning – decide if needs episiotomy
SUPPORT THE PERINEUM!
Ritgen maneuver- increases extension of head
Understand the force / counterforce – you apply counterforce to control the delivery
Head delivered – check for cord
Suction airway
Deliver anterior shoulder – downward traction
Deliver posterior shoulder –upward
Deliver body
Clamp cord/suction airway – hand off baby
Check vagina/perineum
Prepare to delivery placenta – mild traction on cord with counterforce on uterus
SHOULDER DYSTOCIA “the scariest event in obstetrics”
Anterior Shoulder is impacted behind symphysis pubis
DON’T APPLY MORE TRACTION – need to disengage anterior shoulder!
McRoberts maneuver – Flex maternal thighs
Suprapubic pressure
Wood’s screw – try to rotate posterior shoulder upward
Deliver posterior arm
Clavicle fracture
Symphysiotomy
Zavanelli maneuver – manually push head into vagina/uterus followed by stat c/section
Complication – fractures of humerus, clavicle, Erb’s palsy – brachial plexus injury
RETAINED PLACENTA
Placenta retained >/= 30 minutes
Anesthesia/ Uterine relaxing agent
Manual extraction
Curettage under ultrasound guidance