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DYSTOCIA
ANDREW ROULDAN B. BUIZON, M.D., FPOGS, FSGOP
Assistant Professor
De La Salle University – Health Sciences Institute
DYSTOCIA
• Literally means “Difficult Labor”
• Characterized by Abnormally SLOW Progress of Labor
Overview of the lecture
I – Normal and Abnormal Labor
II – Causes of Dystocia
III – Complications of Dystocia
Factors that affect Labor• Power
– First stage: uterine contractions– Second stage: uterine contractions + intra-
abdominal pressure
• Passenger – Fetal Attitude, Presentation, Position– Ability to adapt through Passage
• Passage– Birth canal
• *For Normal Labor to take place – Normal 3P’s
Prognosis for Vaginal Delivery
• Power – force of uterine contractions
• Passenger:– Presentation and Position – Size of fetal head– Adaptability of fetal head
• Passage – size and shape of maternal bony pelvis
Stages of Labor
First* - regular uterine contractions fully
Second*- full cervical dilatation delivery baby
Third - delivery of baby placental delivery
“Fourth” - immediate postpartum
*Stages concerned with Dystocia
First Stage of Labor
• Latent Phase
• Active Phase– Acceleration Phase
• Predictive of outcome of labor
– Phase of Maximum slope• Measure of efficiency of the “machine”
– Deceleration Phase• Reflective of fetopelvic relationship
History of the Partograph
Functional Divisions of Labor
• Preparatory Division
• Dilatational Division
• Pelvic Division
Preparatory Division
• Latent Phase and Acceleration Phase
• Major event – cervical ripening– Softening: changes in ground substance– Effacement: obliteration of cervical canal
• Cervical dilatation – minimal
• Fetal descent – minimal to absent
• Sensitive to sedation and conduction analgesia
Preparatory Division
Functional Divisions of Labor
• Preparatory Division
• Dilatational Division
• Pelvic Division
Dilatational Division
• Phase of Maximum Slope
• Major Event – cervical dilatation
• Cervical Dilatation – most rapid rate
• Fetal Descent – minimal
• Unaffected by sedation and conduction analgesia
Dilatational Division
Functional Divisions of Labor
• Preparatory Division
• Dilatational Division
• Pelvic Division
Pelvic Division
• Deceleration Phase to Second Stage of labor
• Major Event – cardinal movements
• Cervical Dilatation – rapid rate
• Fetal Descent – maximal
• Minimally affected by sedation but ‘bearing down’ effort largely affected by conduction analgesia
Pelvic Division
Cervical Dilatation and Fetal Descent
• The only characteristics of the parturient useful in assessing labor & its progression
• Time vs. Cervical Dilatation – sigmoid curve
• Time vs. Fetal descent – hyperbolic curve
Mechanical Forces of Labor
• Factors responsible for progression and completion of each stage
• First stage:– Uterine power– Cervical resistance– Forward pressure of the fetal head
• Second stage:– Mechanical relationship between fetal head
and pelvic capacity
Diagnosis of Labor
True Labor False Labor
Regularity (+) (-)
Frequency > 1 / 10 min no pattern
Duration > 10 seconds variable
Intensity increasing no pattern
Effect of
walking aggravates no effect
Criteria for Diagnosis of Labor
1. Documented uterine contractions (at Least once in 10 minutes, or 4 in 20 min.) In the form of direct observation or Electronically using a cardiotocogram
2. Documented progressive changes in cervical dilatation and effacement, as Observed by one observer
3. Cervical effacement of greater than 75-80%
4. Cervical dilatation of greater than 3 cm
Diagnosis of Normal Labor
LABOR PATTERN
NULLIPARA MULTIPARA
Latent Phase < 20 hours < 14 hours
Cervical Dilatation
> 1.2 cm/hr > 1.5 cm/hr
Fetal Descent > 1 cm/hr > 2 cm/hr
Diagnosis of Abnormal LaborLABOR
PATTERNNULLIPARA MULTIPARA
Prolongation Disorder
Latent Phase > 20 hours > 14 hours
Deceleration Phase > 3 hours > 1 hour
Protraction Disorder
Dilatation < 1.2 cm/hr < 1.5 cm/hr
Descent < 1 cm/hr < 2 cms/hr
Arrest Disorder
No Dilatation > 2 hours > 2 hours
No Descent > 1 hour > 1 hour
Prolonged Latent Phase
• It is the only disorder diagnosable in the Preparatory Division of Labor
• Criteria:– Nulli > 20 hrs– Multi > 14 hrs
Prolonged Latent Phase
08 12 16 20 24 28
Hours of Labor
2
4
6
8
10
Cer
vica
l Dila
tati
on (
cm)
Etiology of Prolonged Latent Phase
• False Labor = 50% of the time
• Excessive sedation
• Unfavorable cervix (thick, uneffaced, closed)
• Uterine / Labor dysfunction
• Unknown
Management ofProlonged Latent Phase
• Therapeutic Rest – if no C/I to delay for 6-10 hrs– Strong sedatives– Upon waking, 85% = enter active phase 15% = false labor
• Amniotomy – will not accelerate latent phase
• Caesarean section– Not usually done unless with indications
Diagnosis of Abnormal LaborLABOR
PATTERNNULLIPARA MULTIPARA
Prolongation Disorder
Latent Phase > 20 hours > 14 hours
Deceleration Phase > 3 hours > 1 hour
Protraction Disorder
Dilatation < 1.2 cm/hr < 1.5 cm/hr
Descent < 1 cm/hr < 2 cms/hr
Arrest Disorder
No Dilatation > 2 hours > 2 hours
No Descent > 1 hour > 1 hour
Protraction Disorders of LaborD
ilata
tio
nD
esce
nt
A
B
Protraction Disorders
• Protracted Active Phase• Protracted Descent• Etiology :
– Malposition– Excessive sedation / conduction analgesia– Cephalopelvic disproportion
• Management:– Augment of labor– CS = 28% have CPD
Diagnosis of Abnormal LaborLABOR
PATTERNNULLIPARA MULTIPARA
Prolongation Disorder
Latent Phase > 20 hours > 14 hours
Deceleration Phase > 3 hours > 1 hour
Protraction Disorder
Dilatation < 1.2 cm/hr < 1.5 cm/hr
Descent < 1 cm/hr < 2 cms/hr
Arrest Disorder
No Dilatation > 2 hours > 2 hours
No Descent > 1 hour > 1 hour
Arrest DisordersD
ilata
tio
nD
esce
nt
A
B
C
D
Arrest Disorders
• Criteria before diagnosing Arrest disorders:– Latent phase completed (Cx > 4 cms)– Intensity of Uterine contractions > 200 MvU x 2 h
• “2-hour rule” for diagnosis of arrest in active phase of labor has recently been challenged
• 542 women included where CS delivery was delayed until there were at least 4 hours of a sustained uterine contraction of >200 MvU or a minimum of 6 hours oxytocin augmentation if the contraction pattern could not be achieved
Arrest Disorders
• Protocol resulted in high rate of vaginal delivery (92%) w/ no severe adverse maternal or fetal outcomes
• “Thus extending the minimum period of oxytocin augmentation for active arrest from 2 hours to 4 hours appears effective”
ACOG Practice Bulletin, Compendium 2004
Arrest Disorders
• Etiology:– Cephalopelvic disproportion– Hypotonic uterine contraction– Malposition– Excessive sedation / anesthesia
• Management:– CS = 52% have CPD– Augment labor, if no CPD
Management of Abnormal LaborLabor pattern Preferred
TreatmentExceptional Treatment
Prolongation Disorders
Latent Phase Bed rest Augment / CS
Protraction Disorders
Dilatation Expectant / Support
CS for CPD /
AugmentDescent
Arrest Disorders
Prol Decel Augment if no CPD
Rest if exhausted
2o Arrest of Dil
Arrest of Descent CS if + CPD CS
Failure of descent
Abnormal Labor (Based on Friedman’s curve)
Arrest in Cervical DilatationProtracted Active Phase
Prolonged Latent Phase
Prolonged Deceleration PhaseFailure of DescentProtracted DescentArrest of Descent
Spontaneous rupture of membranes
Oxytocin
Normal Labor Pattern
AMNIOTOMY
OXYTOCIN
Arrest in Cervical Dilatation
AMNIOTOMY
OXYTOCIN
Prolonged Deceleration Phase
AMNIOTOMY
OXYTOCIN
Arrest of Descent
Overview of the lecture
I – Normal and Abnormal Labor
II – Causes of Dystocia
III – Complications of Dystocia
DYSTOCIA - Abnormal Labor
• Other names: Dysfunctional labor, Ineffective labor, Failure to progress
Worldwide - Accounts for 43% of all primary cesarean sections
Philippines - it accounts for 38.85% Textbook of Obstetrics,
2002
Risk Factors for Dystocia
• Associated w/ longer 2nd stage- epidural analgesia
- occiput posterior position
- longer 1st stage of labor
- nulliparity
- short maternal stature
- birthweight
- high station at complete cervical dilatationACOG Practice Bulletin
Compendium 2004
DYSTOCIA - Abnormal LaborThree categories causing Dystocia: (Abnormalities of 3Ps)
• POWERS– Uterine contractility– Expulsive Powers (“Bearing down” in the 2nd
Stage of Labor)
• PASSENGER– Presentation, Position, or Development of the Fetus
• PASSAGE– Maternal Bony Pelvis (Pelvic Contraction)– Soft Tissues of the Reproductive Tract
Physiology of Uterine Contractions
Methods to Quantify Uterine Activity
palpation
external tocodynamometry
internal uterine pressure sensors
Physiology of Uterine Contractions
Uterine contractions characterized by a gradient of myometrial activity:
1. Fundal Dominance• Onset, intensity & duration• Cornual area – ‘pacemaker’ of the uterus• Greatest & longest activity at the fundus• Diminishing towards the cervix
Physiology of Uterine Contractions
2. Triple Descending Gradient
• Gradient of contractions diminishes from upper to lower segment
• Upper uterine segment retracts about the fetus as the fetus descends through birth canal
Physiology of Uterine Contractions
• Uterine activity – Montevideo units (MU)– MU = Intensity x Frequency / 10 minutes
• Intensity (intrauterine pressure) = peak contraction
minus baseline contraction • 200 MU = adequate uterine contractions
UTERINE DYSFUNCTION
CLINICAL CRITERIA HYPOTONIC HYPERTONIC
Occurrence 4 % 1 %
Phase of Labor Active Latent
Clinical Symptoms Painless Painful
Fetal Distress Late Early
Reaction to Oxytocin Favorable Unfavorable
Value of Sedation Little Great
Gradient Pattern of Activity
Normal but decreased
Abnormal
UTERINE DYSFUNCTION
Causes of Hypotonic Uterine Dysfunction
• Uterine overdistention
• Grandmultiparity
• Sedation
• Regional anesthesia
HYPERTONIC UTERINE DYSFUNCTION
Also called ‘incoordinate’ uterine dysfunction
Causes:
• Contraction uterine midsegment
• Asynchrony of impulses originating from each cornu
UTERINE DYSFUNCTION
REMEMBER, normally there is:
• LOW uterine activity in ‘Latent phase of labor
• HIGH “ “ ‘Active “ “
So that, if there is:
• HIGH uterine activity in Latent phase of labor
=> HYPERTONIC uterine dysfunction
• LOW uterine activity in Active phase of labor
=> HYPOTONIC uterine dysfunction
CAUSES OF UTERINE DYSFUNCTION
A. Epidural analgesia• Lengthens both 1st and 2nd stage of labor• Slows down rate of fetal descent
B. Chorioamnionitis
C. Maternal position during labor• Uterus contracts more frequently with less
intensity in supine vs. lateral decubitus position• Uterus contracts with more frequency and
intensity in sitting or standing position
William’s Obstetrics, 21st ed.
TREATMENT OF HYPOTONIC UTERINE DYSFUNCTION
• Ascertain parturient is in active labor & no CPD:
– Cervix > 4 cms– Clinical pelvimetry is adequate in all levels– Presenting part is occiput and engaged
• Oxytocin stimulation
TREATMENT OF HYPOTONIC UTERINE DYSFUNCTION
Oxytocin effect uterine activity
• cervical change• fetal descent
avoid uterine hyperstimulation &/or development of non-reassuring fetal heart status
TREATMENT OF HYPOTONIC UTERINE DYSFUNCTION
Oxytocin should be DISCONTINUED• If uterine contractions persist >5 in a 10-
minute period or 7 in a 15-minute period• If the contractions LAST LONGER than 60-
90 seconds• FHR pattern becomes non-reassuring
William Obstetrics 21st edition
Complications of Overinfusion of Oxytocin
hypotension
tachycardia
water retention
Hyperstimulation
Uterine rupture
Fetal distress
TREATMENT OF HYPERTONIC UTERINE DYSFUNCTION
• Characterized by uterine pain out of proportion to intensity of contractions and in effacing & dilating the cervix
• Placental abruption must always be considered
• Fetal distress (+) – CS
(-) - sedation
The Passenger
The Fetus
Position
Presentation
Development
The Passenger• Normal Position – Occiput anterior
• Malpositions:– Persistent Occiput transverse (POT)– Persistent Occiput posterior (POP)
The Passenger• Normal Presentation – Vertex / Cephalic
• Malpresentations:– Brow – Face– Breech– Transverse
• Fetal attitude – relationship bet fetal head & body– Occiput = completely flexed
– Sinciput = partially flexed
– Brow = partially extended
– Face = completely extended
The Passenger• Etiology of deflection attitudes – factors
that favor extension or prevent head flexion:– Neck masses– Anencephaly– Large babies– Cord coils– Contracted pelvis– Pendulous abdomen
The Passenger – Fetal Head Diameters
ATTITUDE PRESENTING DIAMETER
DENOMINATOR
Flexion* Suboccipitobregmatic (SOB) = 9.5 cm
Occiput
Military** Occipitofrontal
(FO) = 11.5 cm
Occiput
Partial Extension**
Occipitomental
(MO) = 12.5 cm
Forehead (Brow)
Complete Extension*
Submentobregmatic
(SMB) = 9.5 cm
Chin / Mentum (Face)
* Vaginal delivery** Unstable / transient presentation – dystocia high
BROW PRESENTATION
• Head is partially extended
• Midway between full flexion & extension
• Rarest presentation
• Longest presenting diameter = 12.5 cm
• Unstable/transient – converts to Face or Occiput presentation
BROW PRESENTATION - Diagnosis
• Abdominal Exam – > ½ of head above symphysis pubis, – Since OM, Vaginal delivery not possible– Leopold’s Maneuver 2 & 3:
• Cephalic prominence same side as fetal back• Occiput and chin palpable
– Occiput palpable at higher level than Sinciput• Occuiput = Posterior fontanel• Sinciput = anterior fontanel
BROW PRESENTATION - Diagnosis
• Vaginal examination– Anterior fontanel– Frontal sutures– Orbital ridges– Eyes– Root of nose
BROW PRESENTATION – Three possible outcomes during course of Labor:
Possible outcome
Mechanism Manner of Delivery
Vertex if head flexes Vaginal
Face if head completely extends
Vaginal
Persistent if no change in position
CS
FACE PRESENTATION
• Fetal head is fully extended / hyperextended• Occiput in contact w/ fetal back, chin presents• Abdominal exam:
– groove felt bet Occiput & Fetal Back
• Vaginal exam:– Distinct facial features– Sinciput & occiput not palpable
• Etiology:– Any factor that favors extension or prevents
flexion (e.g. Anencephaly)
FACE PRESENTATION – Course of Labor
• Chin / mentum anterior:– Expect vaginal delivery -– CS if obstructed labor
• Chin / mentum posterior:– Vaginal delivery possible only if Internally Rotate
anteriorly– Cause of obstructed labor: fetal brow (bregma)
pressed against maternal symphysis pubis – Short neck cannot span the curvature of sacrum
BREECH PRESENTATION
TYPE THIGHS KNEES SACRUM FEET
Complete Flexed Flexed + _
Incomplete (Footling)
Flexed Flexed _ +
Frank Flexed Extended + _
BREECH PRESENTATION
• Leopold’s Maneuver:
• Vaginal Examination:– Ischial Tuberosities– Anus– External Genitalia– Sacrum – Feet
BREECH PRESENTATION
• Possible Etiologies:– Prematurity– Uterine relaxation / Multiparity– Multiple pregnancy– Hydramnios– Oligohydramnios– Hydrocephalus– Anencephaly– Uterine anomalies / tumor– Placente Previa– Habitual breech
BREECH PRESENTATION
• Antenatal Period:– External version may be attempted
• Standard of Care:– Planned CS – to reduce perinatal M & M– Vaginal - In advanced labor of imminent delivery
• Frank / complete• Spontaneous• Partial BE• Total BE
BREECH PRESENTATION
MATERNAL FACTORS FETAL FACTORS
•Pelvic Contraction•Delivery is indicated – patient not in labor•Uterine dysfunction•Lack of Experience Operator
•Large fetus•Hyperextended head “stargazing breech”•Healthy preterm fetus where delivery is indicated•Severe IUGR
Previous Perinatal Death/ Birth Trauma
BREECH PRESENTATION
• Complications– Perinatal M & M – preterm birth, birth trauma,
congenital anomalies– Low Birth Weight – prematurity, IUGR– Prolapsed cord – small fetus, fetus not in
frank breech– Placenta Previa– Uterine anomalies / Tumors
TRANSVERSE PRESENTATION
• Long axis of fetus perpendicular to mother• NO MECHANISM OF LABOR, always CS• Abdomen: SQUAT UTERUS
– Usually wide – Fundus only slightly above umbilicus
• Leopold’s Maneuver: – 1 : empty– 2 : fetal back readily identified
• If anteriror: hard resistant plane• If posterior: irregular nodulations (FSP)
TRANSVERSE PRESENTATION• Vaginal examination:
– Palpate acromion and hands– “Gridiron” – can feel the ribs
• Etiology:– Lax abdominal wall - allows uterus to fall forward, to be
deflected away from long axis of birth canal into an Oblique or Transverse Position
– Prematurity– Placenta previa – Contracted pelvic– Tumor previa– Multiple pregnancy– Fetal uterine anomalies– polyhydramnios
TRANSVERSE PRESENTATION –
Course of Labor• Neglected Transverse Lie
– Prolonged ROM– Stretched / thinned out LUS– Intrauterine infection– Fetal impaction– Prolapsed cord / arm– Dead baby
TRANSVERSE PRESENTATION –
Management• It’s a serious malpresentation
• Management should not be left to nature
• Spontaneous vaginal delivery impossible
• Must deliver by CS immediately
Overview of the lecture
I – Normal and Abnormal Labor
II – Causes of Dystocia
III – Complications of Dystocia
MATERNAL COMPLICATIONS• Hemorrhage & Shock – uterine atony
• Intrapartum infection – ascending type: chorioamnionitis, decidua, chorionic vessels, bacteremia, sepsis
• Uterine rupture – progressive thinning out of LUS in prolonged labor, esp high parity & previous surgery
• Fistula formation – presenting part wedged into pelvic inlet during prolonged labor, tissues of birth canal bet it & pelvic wall subjected to pressure, ischemia, necrosis– Fistula: two cavities joined together (e.g.
rectovaginal or vesicovaginal fistulae)
MATERNAL COMPLICATIONS
• Postpartum lower extremity injury:– Foot drop:
• common peroneal n. + LS plexus or sciatic n.– Inappropriate leg positioning in stirrups– Resolve w/in 6 months postpartum
• Pelvic floor injury:– Directly to pelvic floor m. or their nerve supply
FETAL COMPLICATIONS
• Caput succedaneum:– Soft tissue / scalp edema of most dependent
portion of fetal head– Overlies the periosteum, cross over periosteal
limitations
• Cephalhematoma:– Subperiosteal hemorrhage– Confined by periosteal limits
FETAL COMPLICATIONS – Nerve Injuries
• Spinal injury – overstretching with hemorrhage
• Brachial plexus – – Duchenne / Erb paralysis: (Upper roots)
• Deltoid, infraspinatus, flexor m of forearm• Entire arm fall limply close to side of the body,
forearm extended & internally rotated • Function of hand retained• Excesssive lateral traction upon head, sharply
flexing head toward one of shoulders
– Klumpke paralysis: (Lower roots)• Paralysis of the hand