I 1.Dystocia

8/11/2019 I 1.Dystocia

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DYSTOCIA- Difficult labor- Slow progress of labor

NORMAL LABOR

True labor- Regular painful uterine contractions that bring about cervical dilation and

effacement

When does labor starts?- painful contractions become regular; at the time of admission to

labor unit- duration of labor: admission to delivery

Stages:a. 1ststage: from regular uterine contraction to full cervical dilationb. 2ndstage: from cervical dilation to delivery

Average:Nullipara50 mins (2-3 hours)Multipara20 mins (1-2 hours)

c. 3rdstage: from delivery of fetus to placental expulsion

Functional divisions of labor:a. Preparatorycomprised of latent and acceleration phases; sensitive to

sedation and analgesia; mechanism: change in connective tissuecomponent of cervix

b. Dilationaloccur at most rapid rate; corresponds to rapid dilation of cervixc. Pelviccommences with deceleration phase; cardinal movements of

labor (Edfireere)

2 Phases of cervical dilation:a. Latentpreparatory division; starts from maternal perception of regular

uterine contraction to progressive cervical dilation and ends between 3-4cm dilation; 10% are false labor

b. Active1. Acceleration phasedetermines the ultimate outcome of labor2. Phase of maximum slopeoverall efficiency of the machine

[uterus]3. Deceleration phasereflects feto-pelvic relationship

*dilation of cervixsigmoid curve*descent of fetushyperbolic curve

Average rate of descent:Nullipara: 1cm/hr (7-8cm)Multipara: 2cm/hr

Modified WHO Partograph (2006)- Start at 4 cm cervical dilation (active labor)- 2 observations consist of:

o Cervical dilation and fetal descento Fetus (s.a. heart rate, fluids)

Alert line- Refer to hospital when Cervical dilation moves to the right- Management: AROM

Action line- If curve crosses action line (4 hours to the right of action line)- Mgt: administer oxytocin

Dystocia- difficult labor-abnormally slow progress of labor

-most common indication for primary CS-secondary to:

-abnormalities of power-abnormalities of passenger-abnormalities of passages-abnormalities of birth canal other than bony pelvis

Maternal-Fetal Effects:1. Intrapartum hemorrhage2. Pathological ring of Bandl3. Uterine rupture4. Fistula formation5. Pelvic floor injury

Dystocia

Dr. Bautista

June 6, 2011

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6. Fetal effects (caput, molding, cephalohematomasignifiesbleeding injury to the periosteum)

Abnormal LaborI. Protractionslow rate of dilation/descent; 30% have cephalo-

pelvic disproportion (CPD)II. Arrest disordereither of dilation/descen; 45% CPDIII. Failure of descentIV. Precipitate labordelivery < 3 hours; either dilation/descent,

may result in hemorrhage and intracranial hemorrhage

Nullipara MultiparaProlonged latent > 20 hrs > 14 hrs

Protracted active < 1.2 cm/hr < 1.5 cm/hr

Prolonged deceleration > 3 hrs > 1 hr

Secondary arrest of dilation > 2 hrs > 2 hrs

Arrest of descent > 1 hr > 1 hr

Failure of descent

Precipitate active > 5 cm/hr > 10 cm/hr

Precipitate descent > 5 cm/hr > 10 cm/hr

Abnormalities:I. PassengerII. PassageIII. Power

A. Abnormalities in Power: (uterine dysfunction)Normal contractiongreatest and longest myometrial activity at fundus-15 mm Hg- lower limit of contraction pressure required to dilate-Normal spontaneous contraction = 60 mmHg-Clinical labor starts when uterine activity: ~ 80-120 Montevideo units (cutoff:180 MVU)Types of uterine dysfunction:

1. Hypotonica. No basal hypertonusb. Uterine contraction are synchronousc. Slight increase in pressure insufficient to dilate cervix

Mgt: Augment with oxytocin

*oxytocinnot effective by mouth

Each mL 10 IUHalf-life: 3mins

preparation: 10 U oxytocin in 1 L D5W; total dose 30-40 mL/min

side effects:a. Cardiovascular

Transient fall in BP; must be administered not as IVbolus

ECG changes of MI: increase in CO Increase in mean pulse rate

b. Water intoxication Due to anti-diuretic action

2. Hypertonica. Increased basal toneb. Pressure gradient distortedc. Uterine contraction @ midsegment > fundus

Mgt: Sedate the patientHyperstimulation

1. Persistent tachysystole w/ fetal distress2. Single uterine contraction > 2 min3. UC w/in 1 min of each other

Uterine tachysystole: > 6 UC in 10 mins

Uterine hyperstimulation: lasting > 2mins; fetal heart rate changes

B. Abnormalities in Passenger:1. Abnormal presentation/position

a. Face presentation

head is hyperextended occiput in contact with fetal back

mentum/chin is the presenting part

submento-bregmatic diameter = 9.5 cm (presenting

diameter)

Problem: If mentum posterior, the brow is compressed

against the symphysis pubis preventing the flexion of the

head

Diagnosis:1. Vaginal exam-fetal mouth, malar bones, orbital ridges2. X-ray- hyperextended head

Etiology of face presentation:I. Marked enlargement of the neckII. Anencephalic fetusesIII. Contracted pelvisIV. Very large fetusV. Pendulous abdomenVI. High parity

Mgt: CS is indicatedNo contracted pelvis + effective labor = vaginal bleeding

b. Brow presentation

- rarest;unstable presentation (military position)- fetal head occupies a position midway between full flexion andextension- vertico-mental diameter = 13.5 cm therefore delivery cant takeplace (fetal head between orbital ridge and fontanel)

Diagnosis:1. Abdominal exam- chin and occiput can be palpated2. vaginal- frontal sutures; eyes

Etiology: same as face

Mechanism: engagement

c. Transverse lie

long axis of fetus perpendicular to the mother; shoulder is thepresenting part; either dorso-anterior or dorso-posterior

Etiology:1.Preterm2.Placenta previa3.Abnormal uterus4.Polyhydramnos5.Contracted pelvis

Diagnosis:- Abdomen is unusually wide, no fetal pole detected,ballotable head in iliac fossa

Course:- Spontaneous delivery is impossible; CS is indicatedConduplicato corpore: fetus doubled upon itself

Mgt: CS

d. Compound presentation

extremity prolapses alongside the presenting partEtiology: preterm


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e. Persistent Occiput Posterior (POP)

precise reasons for failure of spontaneous rotation is unknown;painful labor; generous episiotomy is indicated; occiput has to rotate135oinstead of 45othru symphysis

f. Shoulder dystocia

anterior shoulder against symphysis pubis; incidenc due to biggerbabies

Maternal-fetal Consequences:I. Post partum hemorrhageII. Transient brachial plexus palsiesIII. Clavicular and humeral fractures

Risk factors:I. ObesityII. DiabetesIII. Multiparity

ACOG1. most cases cant be predicted2. planned CS delivery reasonable for nondiabetic with EFW> 5

kg or diabetic with fetus EFW> 4.5 kg3. UTZ limited accuracy4. Planned CS based on ___ (di ko mabasa notes ko!!!) is not

reasonable

Mgt:- Initial gentle attempt at traction assisted by maternal expulsive effort

+ large episiotomy and adequate analgesia

Maneuvers:1. Moderate suprapubic pressure2. McRoberts maneuverpelvic outlet 1.5-2cm3. Wood corkscrew maneuver4. Delivery of posterior shoulder5. Rubin maneuver6. Zavanelli maneuverfetus head is pushed back then CS7. Cleidotomy8. Symphysiotomy

Drills (for shoulder dystocia):1. Call for help2. Generous episiotomy3. Moderate suprapubic pressure4. McRoberts maneuver5. Wood corkscrew maneuver6. Delivery of posterior shoulder

2. Fetal malformation:- Hydrocephalus- Abdominal tumors- Cystic hygroma- Conjoined Twins

C. Abnormalities in Passages:1. Pelvic inlet diameters2. Pelvic midplane3. Pelvic outler

A. Antero posterioir diameter

a. Obstetric conjugate- shortest distance between sacralpromontory and symphysis pubis; > 10 cm;OC= DC- 1.5 to 2 cm

b. Diagonal conjugate - can be measured clinicallyfrom lower margin of pubis to sacral promontory; >11.5 cm

c. True/ Anatomic conjugate- upper margin of pubic to sacral

promontory > 11 cmTC= DC-1.2cm

Contracted pelvic inletOC < 10cm or DC < 11.5cm

B. Pelvic Midplane Diameter-at the level of ischial spine

a. Interspinous diameter- 10.5 cm; shortest of the whole pelviccavity

b. AP diameter- 11.5 cmc. Post-sagittal- 4.5 cm; between sacrum and line created by IS

diameterd. IS + PS= 15 cm

Contracted mid-pelvisIS < 8cm or IS + PS < 13.5cm

Suggests contraction:-spines are prominent-pelvic sidewalls converge

C. Pelvic outlet-2 triangular areas having common base

a. AP diameter: lower margin of pelvis to tip of sacrum; 9.5-11.5cm

b. Transverse: between inner ridges of ischial tuberosities; 11cm

c. PS: >7.5 cm

Contracted pelvic outletIS < 8cm

Mgt: do episiotomy

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I 1.Dystocia