Lecture 16 ABNORMAL LABOR: DYSTOCIA Prof. 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: Abnormalities of the powers (uterine contractility and maternal expulsive effort) Abnormalities of passenger (the fetus) 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

1. ABNORMALITIES OF THE POWERS UTERINE DYSFUNCTION hypotonic primary uterine inertia secondary Uterine hypertonic Dysfunction 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

1. ABNORMALITIES OF THE POWERS 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

1. ABNORMALITIES OF THE POWERS 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)

1. ABNORMALITIES OF THE POWERS 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

1. ABNORMALITIES OF THE POWERS 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)

1. ABNORMALITIES OF THE POWERS 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)

1. ABNORMALITIES OF THE POWERS 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

1. ABNORMALITIES OF THE POWERS 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)

1. ABNORMALITIES OF THE POWERS 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

1. ABNORMALITIES OF THE POWERS 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)

1. ABNORMALITIES OF THE POWERS 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

1. ABNORMALITIES OF THE POWERS 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

LABOR-PROCESS RANGE PLAN

1. ABNORMALITIES OF THE POWERS 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

1. ABNORMALITIES OF THE POWERS 4. MANAGEMENT Hypotonic: the rule of treatment = strengthen contractions and prevent PPH THE FIRST STAGE OF LABOR General management: rest eat more liquid food sedation correct acidosis intravenous injection Physical methods: massage uterus emptying the bladder stimulation nipple artificial rupture of membranes (AROM)

1. ABNORMALITIES OF THE POWERS 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

1. ABNORMALITIES OF THE POWERS 4. MANAGEMENT THE SECOND STAGE OF LABOR Forceps or vacuum extractor: second stage of labor cervical fully dilated membranes ruptured fetal survival, presenting part below the level of ischial spine Cesarean section: presenting part upward the level of ischial spine or fetal distress

1. ABNORMALITIES OF THE POWERS 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. ABNORMALITIES OF THE POWERS: UTERINE HYPERCONTRACTILITY 1. CLINICAL FINDINGS AND DIAGNOSIS Coordinated uterine hypercontractility: uterine contraction is normal and maintain the normal polarity, symmetry and a certain rhythm the intensity strength and frequency enhanced Contraction with: long duration short 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 canal Fractures, intracranial hemorrhage of the newborn Postpartum hemorrhage Uterine inversion Infections Fetal distress, death

1. ABNORMALITIES OF THE POWERS: UTERINE HYPERCONTRACTILITY 2. EFFECT ON MATERNAL AND FETUS Rupture of uterus PPH , infection Soft birth canal trauma Fetal distress Fetal death Stillbirth

1. ABNORMALITIES OF THE POWERS: UTERINE HYPERCONTRACTILITY 3. MANAGEMENT Prophylaxis - reduced obstetric brutal operation Must be gentle, slightly and carefully Tocolytic sedatives inhibited contractions: Meperidin Magnesium sulfate Forceps / Vacuum extractor Cesarean section

CESAREAN SECTION

2. ABNORMALITIES OF PASSAGE 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

2. ABNORMALITIES OF PASSAGE CONTRACTED PELVIC INLET 1. simple flat pelvis promontory of sacrum (dotted line) forward dislocation 2. rachitic flat pelvis past history of rickets

2. ABNORMALITIES OF PASSAGE 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

2. ABNORMALITIES OF PASSAGE MIDPELVIC-OUTLET CONTRACTION Funnel shaped pelvic The spines are prominent, the pelvic sidewalls converge

2. ABNORMALITIES OF PASSAGE 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

2. ABNORMALITIES OF PASSAGE 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

2. ABNORMALITIES OF PASSAGE GENERALLY CONTRACTION PELVIC 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)

2. ABNORMALITIES OF PASSAGE GENERALLY CONTRACTION PELVIC DIAGNOSIS Pelvic measurement: external pelvimetry internal pelvimetry (sterile vaginal examination)

2. ABNORMALITIES OF PASSAGE GENERALLY CONTRACTION PELVIC DIAGNOSIS Pelvimetry diagonal conjugate = 12.5-13 cm bi-ischial diameter = 10 cm incisura ischiadica = 5-6 cm angle of subpubic arch = 90°

2. ABNORMALITIES OF PASSAGE GENERALLY CONTRACTION PELVIC 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)

2. ABNORMALITIES OF PASSAGE 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

2. ABNORMALITIES OF PASSAGE 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

2. ABNORMALITIES OF PASSAGE 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 DYSTOCIA Soft tissue canal: lower part of uterus, cervix, vagina previous scar of the birth canal laceration cervical conization and cauterization cesarean section rape injury in a small child caustic abortifacient injury to vaginal vault and cervix Previous scaring of the birth canal may cause tissue rigidity and dystocia Cesarean section is generally required

3. ABNORMALITIES OF PASSENGER 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 malposition persistent occiput posterior persistent occiput transverse 5% sincipital presentation 1.08% anterior asynclitism posterior 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%

3. ABNORMALITIES OF PASSENGER 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)

3. ABNORMALITIES OF PASSENGER 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

3. ABNORMALITIES OF PASSENGER 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

3. ABNORMALITIES OF PASSENGER 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

3. ABNORMALITIES OF PASSENGER 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

3. ABNORMALITIES OF PASSENGER 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

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