lecture 16 abnormal labor: dystocia prof. vlad tica, md, phd

Lecture 16Lecture 16

ABNORMAL LABOR: ABNORMAL LABOR: DYSTOCIADYSTOCIA

Prof. Vlad TICA, MD, PhDProf. Vlad TICA, MD, PhD

ABNORMAL LABOR: DYSTOCIA

When we last talked about childbirth, there are 4 major influencing factors

When one or more factors are abnormal or uncoordinated = abnormal labor

That may exist singly or in combination

ABNORMAL LABOR: DYSTOCIA

DEFINITION

Generally, abnormal labor is very common whenever there is disproportion between the presenting part of the fetus and the birth canal

Dystocia literally means difficult labor and is characterized by abnormally slow progress of labor

CATEGORIES OF DYSTOCIA

According to the factors divided to 3 types:

1. Abnormalities of the powers (uterine contractility and maternal expulsive effort)

2. Abnormalities of passenger (the fetus)

3. Abnormalities of the passage (the birth canal)

1. ABNORMALITIES OF THE POWERS

Abnormalities of the uterine contractility and maternal expulsive effort

Either uterine forces insufficiently strong or inappropriately coordinated to efface and dilate the cervix - uterine dysfunction - or inadequate voluntary muscle effort during the 2nd stage of labor

2. ABNORMALITIES OF PASSENGER (THE FETUS)

excessive fetal size

malpositions

congenital anomalies

multiple gestation

3. ABNORMALITIES OF THE PASSAGE (THE BIRTH CANAL)

pelvic contraction

soft tissue abnormalities of the birth canal

masses or neoplasia

aberrant placental location

UTERINE DYSFUNCTION

hypotonic primary

uterine inertia secondary

Uterine hypertonicDysfunction uterine hypercontractility


1. ABNORMALITIES OF THE POWERS: UTERINE INERTIA

1. ETIOLOGY

Cephalopelvic disproportion / Fetal malposition

Abnormal of uterine muscle

Psychical factors

Imbalance of endocrine system

Administration of analgesia

Others


i. Cephalopelvic disproportion / Fetal malposition

The fetal head or presenting part could not close presses to the cervix and lower uterine segment Fetopelvic disproportion arises from:

diminished pelvic capacity excessive fetal size malpresentation

Failure to progress in spontaneous / stimulated labor This term is used to include lack of progressive

cervical dilatation or lack of fetal descent


ii. ABNORMAL OF UTERINE MUSCLE

Uterine muscle malfunction can result from uterine overdistention or obstructed labor, or both (muscle fiber excessive elongation and contractility decline)

Polyhydramnios, macrosomia, multiple births (twins)

Muscle fiber degeneration (past history of repeat uterus infection, abortion, induction of labor or operation

Myomas, pelvic tumors, myogenic dysplasia or malformed uterus (didelphus, unicornous uterus)


iii. PSYCHICAL FACTORS

fearing labor pain

anxiety

tension

worried about: fetal safety, labor hemorrhage, injury and dystocia

which eventually lead to uterine dysfunction and occur uterine inertia


iv. OTHER FACTORS

hormonal mechanism of uterine activity (deficiency of oxytocin, estradiol, prostaglandin)

excessive sedation, anesthesia, unripe cervix

fatigue , early abdominal pressure

overactive bladder filling (fetal presentation descent)

2.CLINICAL FINDINGS hypotonic uterine dysfunction (coordinated)

Although there are still normal uterine contraction and maintain the polarity, symmetry, and a certain rhythm, but the contraction is weak and feeble, with short duration, long interval and irregular

when the contractions in the acme, no uterus

uplift and stiffen


2.CLINICAL FINDINGS When uterine contractions:

the intrauterine pressure in the lower, and often <15 mmHg,

as a finger pressing on the fundus of uterus a depression could appear

Maternal relative quiet, prolonged process (painless or can endure )

Fetal heart rate changes lately (no anoxia or lately)


2.CLINICAL FINDINGS hypertonic uterine inertia and uncoordinated

contractions

often occur together, elevated resting tone of the uterus

the exciting site of contraction is NOT from the horn of uterus, and in a particular / multiple site, and with uncoordinated rhythm, polarity inversion


2.CLINICAL FINDINGS When uterine contracts the fundus is no firm, and

the mid or lower uterine segment harder than that

The uterus can NOT be completely relaxed, uterine cavity pressure lasting with higher state, but the cervix no dilation and fetal head NO descent progressively

Maternal lasting abdominal pain and fidgety

Fetal heart rate changes early (anoxia)


2.CLINICAL FINDINGS Failure to progress

Lack of progressive cervical dilatation (primiparas):

Prolonged latent phase > 16 hrs

Prolonged active phase > 8 hrs, cervix dilation < 1.2 cm/hrs

Protracted active phase > 2 hrs

Prolonged 2nd stage > 2 hrs


2.CLINICAL FINDINGS Lack of fetal descent

Prolonged descent > 1 cm/h

Protracted descent > 1 h

Prolonged labor > 24 hrs (the total stage of labor)


LABOR-PROCESS RANGE PLAN

3. EFFECT ON MATERNAL AND FETUS

Maternal - fatigue (prolonged progress) - acidosis or dehydration - infection (Prolonged progress , PROM) - postpartum hemorrhage (insufficient

contractility) - cesarean section rate - laceration

Fetus - distress (uterine blood flow and fetal oxygenation )

- birth injury, intracranial trauma (obstructed labor, rare)

- prolapse of umbilical cord - stillbirth


4. MANAGEMENT

Hypotonic: the rule of treatment = strengthen contractions and prevent PPH

THE FIRST STAGE OF LABOR

General management:resteat more liquid foodsedationcorrect acidosisintravenous injection


Physical methods: • massage uterus• emptying the bladder• stimulation nipple • artificial rupture of membranes (AROM)

4. MANAGEMENT

THE FIRST STAGE OF LABOR

Drugs:

Oxytocin: 2.5 U + 5% GS 500ml ( 5mU/ml, 8drop/min, at the beginning)

Diazepam: 10 mg iv (softening the cervix)

Cesarean section:

Following the above management still ineffective or fetal distress


4. MANAGEMENT

THE SECOND STAGE OF LABOR

Forceps or vacuum extractor: second stage of laborcervical fully dilatedmembranes ruptured fetal survival, presenting part below the level of

ischial spine

Cesarean section: presenting part upward the level of ischial spine

or fetal distress


4. MANAGEMENT

HYPERTONIC - the rule of treatment = Adjusted contractions and resume a normal polarity and rhythm

Sedative: Dolantin or Morphine - adjusted

and resume to a normal contractions Cesarean section: otherwise


1. CLINICAL FINDINGS AND DIAGNOSIS

Coordinated uterine hypercontractility: uterine contraction is normal and maintain the

normal polarity, symmetry and a certain rhythmthe intensity strength and frequency enhanced

Contraction with:long durationshort interval

1. ABNORMALITIES OF THE POWERS:UTERINE HYPERCONTRACTILITY

1. CLINICAL FINDINGS AND DIAGNOSIS

Precipitate delivery (multiparas)the total stage of labor < 3 hrs the process of labor is too fast

Birth injuries lacerations of the soft birth canalFractures, intracranial hemorrhage of the newborn

Postpartum hemorrhageUterine inversion InfectionsFetal distress, death


2. EFFECT ON MATERNAL AND FETUS

Rupture of uterus

PPH , infection

Soft birth canal trauma

Fetal distress

Fetal death

Stillbirth


3. MANAGEMENT

Prophylaxis - reduced obstetric brutal operationMust be gentle, slightly and carefully

Tocolytic sedatives inhibited contractions:

Meperidin

Magnesium sulfate

Forceps / Vacuum extractor

Cesarean section


CESAREAN SECTION

THE BIRTH CANAL

pelvic contraction

soft tissue abnormalities of the birth canal

masses or neoplasia

aberrant placental location

2. ABNORMALITIES OF PASSAGE

PELVIC CONTRACTION

Bony pelvis - a main composing part of birth canal; its size and shape have the direct relation to the course of labor and delivery

Any contraction of pelvic diameter that diminishes the capacity can create dystocia

There may be contractions of the:pelvic inlet, the midpelvis, the pelvic outlet or a generally contracted pelvis caused by

combinations of these


CONTRACTED PELVIC INLET

1. simple flat pelvis

promontory of sacrum (dotted line)

forward dislocation

2. rachitic flat pelvis

past history of rickets


CONTRACTED PELVIC INLET

1. CLINICAL FINDINGS

Fetopelvic disproportion, malposition or malpresentation (face and shoulder presentations are encountered 3x more frequently)

Uterine inertia and prolonged progress of labor (prolonged latent phase, early active phase and protracted active phase)

Cord prolapse occurs 4-6 x more frequently


MIDPELVIC-OUTLET CONTRACTION

Funnel shaped pelvic

The spines are prominent, the pelvic sidewalls converge


MIDPELVIC-OUTLET CONTRACTION

CLINICAL FINDINGS

Fetopelvic disproportion persistent occiput posterior position or deep transverse arrest, molding of head and caput succedaneum

Protracted active phase / prolonged second stage (secondary uterine inertia)

Uterine rupture, perineal tears obstructed labor


GENERALLY CONTRACTION PELVIC

Each pelvic plane is 2 cm less than normal value or more

Can be seen in shape more short and small, well-balanced women of type of figure



DIAGNOSIS

A history of Rickets, bone tuberculosis, polio or pelvic fracture (warrants careful review of previous radiographs and possibly computed tomographic pelvimetry later in pregnancy)

Physical examination height, spine, lower limb disability(height < 150cm , lateral curvature usually associated with contracted pelvis)



DIAGNOSIS

Pelvic measurement:

external pelvimetry

internal pelvimetry (sterile vaginal examination)



DIAGNOSIS

Pelvimetrydiagonal conjugate = 12.5-13 cmbi-ischial diameter = 10 cmincisura ischiadica = 5-6 cmangle of subpubic arch = 90°



DIAGNOSIS

The fetal position and dynamic monitoring of labor

After onset of labor, in primipara, fetal head

unengagement, breech, shoulder presentation; birth process has been slow (Prompt the contraction of pelvis)


MANAGEMENT

Trial labor - under the effective uterine contractions observed the progress of labor

There is no reliable method for evaluating the adequacy of the lower pelvic

The vaginal examination should be performed early in the course of labor

With continuous fetal monitoring, fetal well-being may be ensured


MANAGEMENT

True inlet contracted: Cesarean section

Midpelvic-outlet contraction: fetal head biparietal diameter reached the level of the spines, and can be depressed farther, the fetal presentation beyond station plus 2, vaginal delivery usually is possible; otherwise cesarean section

Administration of oxytocin should avoided in true midpelvic-outlet contraction


MANAGEMENT

Generally contraction pelvic term fetus (birthweight > 3000 g) needed cesarean section

The fetus is not big, fetopelvic is adaptation and without complication can try to labor

Deformed pelvic: cesarean section


Soft tissue canal: lower part of uterus, cervix, vagina previous scar of

the birth canal lacerationcervical conization and cauterization

cesarean sectionrape injury in a small childcaustic abortifacient injury to vaginal vault and

cervix

Previous scaring of the birth canal may cause tissue rigidity and dystocia

Cesarean section is generally required

SOFT-TISSUE DYSTOCIA

FETAL DYSTOCIA caused by:

malposition and malpresentation

excessive size of the fetus fetal malformation

If no disproportion exists, the head readily enters the pelvis, and vaginal delivery can be predicted

3. ABNORMALITIES OF PASSENGER

i. MALPOSITION AND MALPRESENTATION

a. vertex malpositionpersistent occiput posterior persistent occiput transverse 5%sincipital presentation 1.08%anterior asynclitismposterior asynclitism 0.5%-0.81%

b. brow presentation 0.03%-0.1%

c. face presentation 0.08% -0.27%

d. breech presentation 3%-4%

e. abnormal fetal lie - transverse/oblique lie 0.25%


PERSISTENT OCCIPUT POSTERIOR OR TRANSVERSE POSITION (POP, POT)

DEFINITION:

Up to later stage of delivery the occiput can’t rotate anteriorly, persistent occiput posterior (POP) or transverse position (POT)

Most often , the result of malrotation of occiput anterior position during labor (2/3)


ETIOLOGY:

Abnormal pelvic - Anthropoid and android, transverse narrowing of the midpelvis, the fetal head often engages in OP or OT

Bad flexion - fetal backbone near the maternal backbone, which disadvantages fetus flexion

Uterine inertia - influence fetal descent, flexion, internal rotation

Cephalopelvic disproportion - the pelvic cavity is narrow, which limits fetal descent, flexion, internal rotation

Others - placenta praevia, filling of bladder, myoma


CLINICAL FINDING AND SYMPTOMS

Fetal head engages later at the onset of labor Concordant uterine inertia and slow dilatation

of cervix, induces prolonged active phase or 2nd stage

Early use abdominal pressure before the cervix full dilate


TREATMENT

The 1st stage: strengthen contractions, trial labor

Latent phase:sufficient rest and nourishment (Pethidine or

Diazepam)

Active phase:AROM - cervix 3-4 cm, membranes intact. To induce

fetal head descending, strengthen contraction, and internal rotation

Oxytocin intravenous drip infusion (small dose, 2-2.5 u)

Cesarean section - after treatment the labor is still not progressing or fetal distress occurs


TREATMENT

The 2nd stage:

Midwifery - BPD arrive the ischial spine plane or below, s>+2 , to rotate the occiput to OA, vaginal delivery forceps

Cesarean section - fetal head is much high or CPD


TREATMENT

The 3rd stage:

To prevent PPH - prolonged labor readily cause bleeding of uterine inertia

Oxytocin - large dose, intravenous drip infusion (20 u)

Suture lacerations

Antibiotic


THANKS !

lecture 16 abnormal labor: dystocia prof. vlad tica, md, phd

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