MALPRESENTATION AND MALPOnnnnnSITION.ppt

MALPRESENTATION AND MALPOnnnnnSITION.ppt

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  Malposition and Malpresentation 1
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  Definition of Terms •Presentation- the part of the fetus which occupies the lower uterine segment. • Lie – the relationship between the long axis of the fetus and the mother (longitudinal ,Transverse and Oblique) • Attitude- position of the fetal head in relation to the neck 2
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  Definition of Terms… Denominator-It is an arbitrary fixed bony point at the presenting part which come in relation with the various quadrants of the maternal pelvis. Occiput, Sacrum, Mentum, Frontal and Acromion Position- It is the relation of the denominator to the different quadrants of the maternal pelvis. Cardinal movement: Engagement,Descent,Flexion,Internalrotation,Extensition,External rotation ( Restitution ) and Expulsion Engagement- means maximum transverse diameter of the presenting part passes through the pelvic brim. • For head bi-parietal diameter. • For breech bi-trochanteric diameter 3
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  Malposition Malposition is abnormalposition of the vertex (other than occipito-anterior position (DOA,ROA and LOA)) of the fetal head relative to the maternal pelvis. Malpresentation Any fetal presentation other than a vertex presentation 4
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  Etiologies of Malpresentation/Malposition FetalMaternal • Multiple pregnancy • Congenital anomalies- anencephaly, hydrocephalus, fetal tumors, fetal hydrops • Fetal macrosomia • Conjoined twins • Polyhydramnios • Oligohydramnios • Placenta previa • Preterm labor/prematurity • Uterine congenital anomalies- arcuate, septate, didelphys, unicornuate uteri • Contracted pelvis • Grand multiparity • Uterine myoma • Genetic predispositions- family history of malpresentations Most known causes of mal-presentations act by preventing the natural rotation of the fetal head to the lower segment around the 34th week or above and also by preventing the stabilization and fixation of the fetal head in the pelvic inlet around term. 5
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  Malposition Classification of Malposition Occiputposterior (DOP,LOP, ROP) Persistent occiput transverse position (ROT, LOT) Occiput posterior Occiput posterior position is when the fetal occiput is posterior in relation to the maternal pelvis. 6
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  1. Occiput posteriorposition Most, 90%, occiput posterior positions undergo spontaneous anterior rotation. Transverse narrowing of the midpelvis is a risk factor. Is associated with partial deflection of the head and hence the occipito frontal diameter (11.5 cm) is presenting. ROP is more common than LOP - Large bowel on the left side 7
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  Diagnosis Suggestive abdominal findings:- Flattenedlower part of the abdomen. Anteriorly palpable fetal limbs. Fetal heart heard in the flank. More marked fetal movement On vaginal examination:- Posterior fontanelle towards the sacrum. Anterior fontanelle felt anteriorly if neck is flexed. 8
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  • Mechanism oflabor • Two types of OP: - Flexed OP: suboccipito bregmatic( 9.5 cm) and biparietal diameters (9.5 cm) are the presenting diameters. - Deflexed OP: occipitofrontal( 11.5 cm) and biparietal diameters engage. Progress depend on flexion!! 9
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  Management Labor and deliveryneed not differ remarkably from that with the occiput anterior. The possibilities for vaginal delivery: 1 -Spontaneous delivery. 2 -Forceps delivery with the occiput directly posterior. 3 -Manual rotation to the anterior position followed by spontaneous or forceps delivery. 4 -Forceps rotation of the occiput to the anterior position and delivery 10
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  • Spontaneous delivery -Roomyoutlet with relaxed perineum. -Generous episiotomy is usually needed. • Forceps delivery as an occiput Posterior -Forceps put midway between the occiput and sinciput. -Initial traction directed posteriorly and as the glabella is at the apex of pubic arch the traction should be anterior. 11
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  • Manual Rotation. •The effective method is to rotate the sinciput posteriorly. • Determine the exact position. • For ROP use the right hand to grasp the sinciput, displacing upward to increase flexion. • Middle finger in the frontal suture as a marker. • The thumb and other fingers around the bitemporal region. • For the LOP, we use the left hand • The free hand applied over the maternal flank to promote rotation. 12
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  Persistent occiput transverseposition (ROT, LOT)  Persistent occiput transverse position is an occiput transverse position that is maintained for an hour or more in the second stage of labor Classification  High transverse arrest (arrest above station +2 )  Deep transverse arrest (arrest below station +2) 13
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  Causes and riskfactors Inadequate power (contraction and poor pushing) Platypelloid and android pelvis. Fetal head in long occipito-frontal diameter. Diagnosis  On vaginal examination the fetal sagittal suture and fontanelles are palpable in the transverse diameter of the pelvis; the fetal ears can be palpated superiorly under the symphysis and inferiorly above the sacrum/coccyx. 14
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  Management Expectant management: If thereis any progress in descent and the fetal heart rate is reassuring, expectant management is the preferred option. Partial or complete rotation may still occur spontaneously. Augmentation. Caesarean delivery if there is high transverse arrest despite adequate uterine contraction and maternal expulsive effort 15
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  Abnormal Axial Lie Diagnosedin approximately 1 in 300 cases, at term. Occurs if the fetal spine or long axis crosses that of the mother. Diagnosis made by palpation or vaginal examination and verified by ultrasound. An arm, foot, or a shoulder be the presenting part. Prematurity is often a factor, with abnormal lie reported to occur in about 2 percent of pregnancies at 32 weeks, or six times the rate found at term. 16
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  Abnormal Axial Lie… Multipartyparity, contraction or deformity of the maternal pelvis, and abnormal placentation are also the most commonly reported clinical factors associated with abnormal lie. Could be – oblique or transverse or unstable. Unstable if the fetal membranes are intact and there is great fetal mobility resulting in frequent changes of lie or presentation. Perinatal mortality for unstable or transverse lie varies from 5 percent to 25 percent, with maternal mortality as high as 10 percent • Cord prolapse occurs 20 times as it does with a cephalic presentation. 17
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  Management: • Exclude amajor fetal malformation and abnormal placentation. • Expectant management before term. • Active intervention at or beyond 37weeks or after confirmation of fetal lung maturity. • External cephalic version with subsequent induction of labor(Stabilization induction). 19
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  • Cesarean deliveryis indicated if: • External version is unsuccessful or unavailable • Spontaneous rupture of membranes occurs • Active labor has begun with an abnormal lie 20
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  Deflection Attitudes Attitude refersto the position of the fetal head in relation to the neck. The normal attitude is full flexion on the neck, with the fetal chin against the upper chest. Deflexed attitudes include various degrees of deflection or even extension of the fetal head on the neck. Management • Spontaneous conversion to a more normal flexed attitude or further extension of an intermediate deflection to a fully extended position commonly occurs as labor progresses. • Cesarean delivery is the only appropriate alternative when arrest of progress is observed. 21
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  Malpresentation • Any fetalpresentation other than a vertex presentation • Normal presentation is vertex presentation with flexed attitude. • The fetus normally assumes a vertical orientation or lie and a cephalic presentation, with the fetal vertex flexed on the neck(95%). • Deviation occurs from the normal lie, presentation, or flexion attitude , fetal malpresentation.(5%) • Are associated with maternal and perinatal morbidity and mortality much higher than the vertex presentation. 22
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  Presentation may be Cephalic95% Vertex 99% Face 1:500 Brow 1:1500 Breech 3 - 4% at term Shoulder 1:200 Compound Cord presentation 23
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  Vertex 99% Face 1:500 Brow1:1500 24
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  Face presentation • Ischaracterized by a longitudinal lie and full extension of the fetal head on the neck, with the occiput against the upper back. • The fetal chin (mentum) is chosen as the point of designation during vaginal examination. • Incidence is 1 in 500 deliveries. • Many infants with a face presentation have malformations. 25
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  Etiologies • Conditions thatfavor extension or prevent head flexion – Fetal neck soft tissue masses or goiter – Preterm fetuses – coils of cord around the neck – Hydramnios – Anencephaly found in one third of the cases – Contracted pelvic (specially inlet) – High parity 26
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  In face presentation: •The presenting diameter in Mentoanterior is Sub-mento-bregmatic(9.5cm) • The presenting diameter in Mentoposterior is bregmotrachelar( 18cm) Denominator in face presentation – Mentum • The prognosis for labor with a face presentation depends on the orientation of the fetal chin. • At diagnosis: - Mentoanterior 60 to 80% - Mentoposterior 20 to 25 % - Mentotransverse 10 to 15 % 27
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  Attempts to converta face presentation manually into a vertex presentation, manual or forceps rotation of a persistently posterior chin to a mentum anterior position, and internal podalic version and extraction are dangerous and not attempted. In the case of an average or small fetus, adequate pelvis, and hypotonic labor, oxytocin may be considered. 28
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  • Most mentotransverseand 25 to 33 percent of mentoposterior infants will rotate . • In mentoanterior vaginal delivery is possible as the vertex fit into the hollow of the sacrum and the chin fits under the symphysis. • The birth of the head in mentoposterior position is impossible as the fetal brow pressing over the symphysis precludes flexion. 29
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  Fig. Face withLMA 30
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  Fig. Face withRMA 31
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  Diagnosis Suggestive abdominal finding: Deepdepression between the back and the head…’S’ shape of the fetal spine Groove may be felt between the occiput and the back On vaginal examination Fetal chin, mouth and nose palpated. The mouth with the two malar bone prominences make a triangle (unlike in breech where the anal orifice with two trochanteric eminences are in a line) Radiography •Demonstration of the hyperextended head with the facial bones at or below the pelvic inlet 32
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  To differentiate facefrom breech 1. Face – sucking reflex, palpate gum, mentum + two maxillae makes a triangle 2. Breech – meconium may be obtained, anus is on midline b/n the ischial tubrosities, anal sphincter tone is more than the tone of the mouth. 3. X-ray Hyper extended head Facial bones at or below pelvic inlet 33
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  Management of FacePresentation • Overall, 70% to 80% of infants with face presentation can be delivered vaginally, either spontaneously or by low forceps, whereas 12% to 30% require cesarean delivery. • Assess fetal size, pelvic adequacy and the presence of anomalies at initial diagnosis. • In the absence of a contracted pelvis and with effective labor, successful vaginal delivery usually will follow 35
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  • Fetal heartrate monitoring is probably better done with external devices to avoid damage to the face and eyes • Follow labor progress and ascertain internal rotation to mento anterior position • Manual rotation to mento anterior position, internal podalic version and extraction are an outdated management 36
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  Persistent mento-posterior presentation: •Mento-posterior in the later part of the first stage(after 6 cm of cervical dilatation) and second stages of labor. • If fetus is alive → Cesarean delivery • If the fetus is dead → Craniotomy if all the prerequisites are met 37
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  Complications • Prolonged labor:oxytocin may be considered in hypotonic labor? • Worsening of the fetal condition is 10 fold higher. - Continuous intrapartum electronic fetal heart rate monitoring. - Care must be taken in the placement of an electrode to avoid cosmetic injury to the face. • Nerve damage to the neonate with forced flexion during C/S. • Laryngeal and tracheal edema resulting from pressures of the birth process. 38
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  Brow presentation • Occupiesa longitudinal axis, with a partially deflexed cephalic attitude, midway between full flexion and full extension. • The portion of the head between the orbital ridge and the anterior fontanel presents at the pelvic inlet. • The frontal bones are the point of designation. • The engaging diameters are the mentovertical (13.5cm) and biparietal (9.5cm). -the largest pelvic diameter is 13 cm. -labor is impossible with normal baby and fetus. 39
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  • Frontum anterioris reportedly the most common position at diagnosis, occurring about twice as often as either transverse or posterior positions. • Incidence is 1 in 10,000 ( Williams), 1 in 1,500( Gabbe). • On abdominal palpation both the occiput and chin can be palpated easily. • Brow presentation is commonly unstable and often converts to a face or vertex presentation , about 91% in adequate pelvimetry. • Risk factors: -Cephalopelvic disproportion -Prematurity -Great parity -An open fetal mouth pressed against the vaginal wall. 40
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  One unexpected causeof persistent brow presentation may be an open fetal mouth pressed against the vaginal wall, splinting the head and preventing either flexion or extension 41
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  Diagnosis Suggestive abdominal finding: Occiputfelt above Sinciput. Free head with ROM Unengaged head in primigravida at term Prolonged labor Leopold’s palpation- “ military” attitude 42
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  Perivaginal Diagnosis is rarebefore labor Frontal suture Large anterior fontanel  4 lines felt unlike 3 of posterior fontanel Orbital ridges, eyes, roots of nose In brow presentation extensive moulding & caput occurs 43
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  Management Antenatal  Expectant since50% undergo spontaneous conversion to face(20%) or vertex(30%).  The patient should come to hospital immediately if labor starts or membrane ruptures. In labor  If labor progresses with no distress  no interference, chance of change to face or vertex in 2-3 hours. • If brow presentation diagnosed in early labor with no maternal OR fetal compromise, we may wait and review the condition after 2 to 3 hours. • If still brow … emergency cesarean section! • If brow presentation diagnosed in established labor with signs of obstructed labor emergency cesarean section! 44
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  Management… • Mechanism oflabor – varies with size of the fetus. • Very small fetus & large pelvis – engagement and delivery is possible. • Large fetus – engagement is impossible unless: extensive moulding, flexion to vertex, extension to face. • Forced conversion of the brow to a more favorable position with forceps or manual is contraindicated. • Trial of labor with careful monitoring of maternal and fetal condition may be appropriate. 45
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  Management… Persistent brow presentationis brow presentation in the later part of the first stage (after 6 cm of cervical dilatation) and second stages of labor. If the fetus is alive deliver by cesarean section.  If the fetus is dead: Perform craniotomy if the cervix is fully dilated and the head is accessible and other prerequisite for craniotomy are met: 46
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  Management… Deliver by caesareansection if:- The cervix is not fully dilated or station is high. The operator is not proficient in craniotomy. Do not use an obstetric vacuum or forceps with brow presentation. Augmentation of labor is also not generally recommended in brow presentation. 47
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  Complications Rupture of fetalmembranes Cord prolapse → fetal distress →fetal death Marked molding Rupture of fetal membranes Prolonged and complicated labour Maternal distress, dehydration, ketoacidosisInfection No engagement of presenting part Obstructed labour → uterine rupture →maternal death Maternal complication Fetal complication 48
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  Shoulder presentation • Shoulderpresentation occurs with the fetus is in the . • In late labor, shoulder presentation may be accompanied by a hand prolapse. • Diameter attempting to be delivered in shoulder presentations is the crown-rump length • The long axis of the fetus is approximately perpendicular to that of the mother. 49
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  Shoulder presentation… • Theshoulder is usually over the pelvic inlet, shoulder presentation. • The head lies in one iliac fossa, and the breech in the other. • The acromion and the back are important for designation. • The dorsum can be directed anteriorly or posteriorly, superiorly or inferiorly. • Incidence is 1 in 335 singleton fetuses. 50
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  Risk factors High parityRelaxed and pendulous abdomen The uterus falls forward, and deflecting the long axis of the fetus away from the axis of the birth canal Preterm fetus  Placenta previa Abnormal uterine anatomy  Hydramnios  Contracted pelvis Multiple pregnancy. 52
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  Diagnosis Abdominal Examination finding •The abdomen is unusually wide. • Fundal height is less than gestation age. • The uterine fundus extends to only slightly above the umbilicus. • No fetal pole is detected in the fundus. • Ballot table head is found in one iliac fossa and the breech in the other. 53
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  Vaginal examination • Indelayed and neglected cases the hand and arm may prolapse. • Cord prolapse rate is the highest among the malpresentations (20%). • Depending on the position of dorsum, the shoulder, hands or parts of the ribs may be felt on vaginal exam. • Clinical pelvimetry should be performed Sonography • In addition to confirming the diagnosis, presence of congenital anomalies, placenta previa, uterine anomalies and fetal size assessment should be made. 54
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  Management • Vaginal deliveryof a fully developed newborn is impossible with a persistent transverse lie. • After rupture of the membranes the fetal shoulder is forced into the pelvis, and the corresponding arm frequently prolapses. • The onset of active labor in a woman with a transverse lie is an indication for emergency cesarean delivery. • ECV should be tried if the membrane is intact and no contraindications. 56
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  Management… • If thepelvis is large and the fetus is small, spontaneous evolution could take place: oArm and shoulder descend behind the symphysis. oThe chest descend into the pelvis. oThe breech follows. oDelivery follows as with breech with one arm extended. 57
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  If the fetusis small, less than 800 g, and dead it may double upon itself and get expelled, conduplicato corpore. 60
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  Compound Presentation • Compoundpresentation is when a fetal extremity prolapses alongside the main presenting part. • It usually is the hand alongside the fetal head. • Incidence of 1 in 700 deliveries. • Although maternal age, race, parity, and pelvic size have been associated with compound presentation, prematurity is the most consistent clinical finding. Diagnosis Antepartum obstetrical ultrasound examination. vaginal examination: Irregular mobile fetal part adjacent to the larger presenting part 61
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  Intrapartum management • Observationin normally progressing labor because 75% of vertex/upper extremity combinations deliver spontaneously. • Closely monitor labor. The prolapsed extremity should not be manipulated as it may retract with the descent of the main presenting part. • Spontaneous vaginal birth can occur only when the fetus is very small or dead and macerated. • Cesarean delivery is indicated if there is protraction or arrest of labor. 62
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  • Augmentation oflabor and instrument use is not recommended • Occult or undetected cord prolapse is possible, and, therefore, continuous electronic FHR monitoring is recommended. • Cord prolapse occurs in 10% to 20% of cases. Outcomes: - Most cases result in uncomplicated vaginal delivery( up to 75%). - Ischemic necrosis of the arm (both neurologic and musculoskeletal injury). 63
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  Parietal presentation/Asynclitism/Lateral flexion Synclitism:The posture in which the 2 parietal bones are at the same level. Asynclitism: The posture in which one parietal bone is at a lower level than the other due to lateral inclination of the head. Asynclitism is beneficial in bringing the shorter subparietal or supraparietal diameter (9 cm) to enter the pelvis instead of the longer biparietal (9.5 cm). Slight degree of asynclitism may occur in normal labour 64
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  65 Thank you