MALPRESENTATION AND MALPOSITION

MALPRESENTATION AND MALPOSITION INTRODUCTIONNear term and during labour, the foetus normally assumes a longitudinal lie and presents with the cephalic pole to the maternal pelvis with the neck flexed and the vertex in the lowermost part of the uterus. In approximately 5% of labours, the lie is not longitudinal. This is usually associated with dangers to both mother and fetus and demands intervention.malpositionA fetal malpositions refers to when the fetal vertex presents to the maternal pelvis in a position other than an occipitoanterior position.

malpresentationA condition in which a baby is not in the usual head-first position forchildbirth. Malpresentation includes breech presentation (the babys bottom appears first), face presentation, and shoulder presentation (in which the baby is lying across the uterus). Breech presentations are the most common.

classificationThus the various presentations are:cephalic presentation(head first):vertex (crown)sinciput(forehead)brow (eyebrows)Facechinbreech presentation (buttocks or feet first):complete breechfootling breechfrank breechshoulder presentation:ArmShouldertrunk

AttitudeDefinition: Relationship of fetal head to spine:flexed, (this is the normal situation)neutral (military),extendedposition Definition: Relationship of presenting part to maternal pelvis: and based on presentation:Cephalic presentationVertex with longitudinal lieLOAROALOPROPOPOAb. Face presentation

2. Breach presentaionLSARSALSPRSP

SASP3. Shoulder presentation with transverse lieLeft scapula-anterior (LSA)Right scapula-anterior (RSA)Left scapula-posterior (LSP)Right scapula-posterior (RSP)LieDefinition: Relationship between the longitudinal axis of fetus and maternal pelvislongitudinal, (resulting in either cephalic or breech presentation)oblique, (unstable, will eventually become either transverse or longitudinal)transverse (resulting in shoulder presentation).

Occipito posterior positionINTRODUCTIONOccipito posterior positions are the most common type of the occiput and occur in approximately 10% of labours. A persistent occipito posterior position results from a failure of internal rotation prior to delivery. This occurs in 5% of deliveries.All the three position( LOP, ROP, OP) may be primary or secondary.

DEFINITIONIn a vertex presentation where the occiput is placed posteriorly over the sacroiliac joint or directly over the sacrum, it is called an occipito posterior position.causesShape of the pelvic inletmore than 50% is associated with either anthropoid or android pelvis

Fetal factors- Marked deflexion of the fetal head.Abruptio placentaBrachycephaly (flat head syndrome)

Uterine factors- Abnormal uterine contraction diagnosisANTENATALABDOMINAL EXAMINATIONON INSPECTIONthere is a saucer shaped depression at or just below the umbilicus.

ON PALPATIONWhile the breech is easily palpated over the fundus the back is difficult to palpate Limbs can be felt on both sides of the midline.Non engagement of the headOn auscultationthe fetal back is not well flexed so the chest is thrust forward, therefore the fetal heart can be heard in the midline. However the heart may be heard more easily at the flank on the same side as the back.Diagnosis during laborWomen complain of continuous and severe back painSlow decent of head.Women may have strong desire to pushIn-coordinated contractionVaginal examinationThe findings in early labour areElongated bag of membranes The sagittal suture occupies the any of the oblique diameter of the pelvis.Posterior fontanalle is felt near the sacroiliac joint.The anterior fontanelle is felt more easily because of deflexion of the headIn late labourDiagnosis is difficult because of caput formation.USGIt is rarely done. It is helpful to know the descent, attitude for the head and its relation to the pelvic walls (position).

MECHANISM OF THE OCCIPITO POSTERIOR POSITION

In the occiput posterior position, the head engages in the right oblique diameter for the ROP and in the left oblique diameter for the LOP. The engaging transverse diameter is biparietal (9.5cm) and the anteroposterior diameter is either suboccipitofrontal (10cm) or occipitofrontal (11.5cm).

POSSIBLE COURSES OF LABOUR

LONG INTERNAL ROTATION: This is the commonest outcome with increasing flexion the occiput reaches the pelvic floor and rotates 3/8th of a circle forward to an occiput anterior position. Mechanisms will then continue as in an anterior position (LOA or ROA). In about 90% delivery occurs in thin manner.

SHORT INTERNAL ROTATIONChance for two possible outcomesFace to pubis deliveryPersistent occipito posterior positionThe term persistent occipito posterior position indicates that the occiput fails to rotate forwards. Instead the sinciput reaches the pelvic floor first and rotates forwards. The occiput goes into the hollow of the sacrum. The baby is born facing the pubic bone (face to pubis).

Deep transverse arrestThe head descends with some increase in flexion. The occiput reaches the pelvic floor and begins to rotate forwards. flexion is not maintained and the occipitofrontal diameter becomes caught at the narrow bispinous diameter of the outlet. Arrest may be due to weak contractions, a straight sacrum or a narrowed outletMECHANISAM OF ROPLie - LongitudinalAttitude deflexedPresentation VertexPosition ROPDenominator occiputPresenting part middle or anterior area of the left parietal bone FlexionInternal rotation of the headCrowningExtensionRestitutionInternal rotation of the shoulderExternal rotation of the headLateral flexion complicationObstructed labourMaternal traumaNeonatal traumaCord prolapsedCerebral haemorrhageManagement Principles:Early diagnosis.Strict vigilance with watchful expectancy hoping for descent and anterior rotation of the occiput.Judicious and timely interference, if necessary.

Early CSoccipito posterior per se is not an indication of caesarean section. Pelvic inadequacy or its unfavourable configuration, along with obstetric complications such as, pre-eclampsia, post caesarean pregnancy, big baby usually need caesarean section.

First stage: Can do normally. The following are the instructions need to follow;Anticipating prolonged labor, intravenous infusion line is sited and ringers solution drip is started.Progress of labour is judged by-Progressive descent of the headRotation of the back and the anterior shoulder towards the midline.Increasing flexion of the headPosition of the sagittal suture on vaginal examinationCervical dilatation.Weak pain, persistence of deflexion and non-rotation of the occiput are the triad too often coexistent. In such a situation, oxytocin infusion is started for augmentation of labour.Indication of caesarean section: arrest of labour, incordinate uterine action, fetal distress.

Second stage In majority anterior rotation of the occiput is complicated and the delivery is either spontaneous or can be accomplished by low forceps or ventouse.In minority (unrotated and malrotated): - watchful expectancy for the anterior rotation of the occiput and descent of the head - In occipito-sacral position, spontaneous delivery as face to pubis may occur. In such cases, proper conduction of delivery and liberal episiotomy should be done to prevent complete perineal tear.

Third stage Because of prolongation of labour, tendency of postpartum haemorrhage can be prevented by prophylactic intravenous Ergometrine 0.25mg with the delivery of anterior shoulder. Arrested occipito posterior position

If there is failure to progress (arrest) in spite of good uterine contractions for about -1 hour after full dilatation of the cervix, interference is indicatedPer abdomen: the following conditions are assessed,Size of the babyEngagement of the headAmount of liquor

Vaginal examination: the following conditions are to be noted,Station of the headPosition of the sagittal suture and the occiputDegree of deflexion of the headDegree of moulding and caput formationAssessment of the pelvis at and below the level of obstruction i.e. ischial spines, side walls of the pelvis, sacro-coccygeal plateau, pubic arch and transverse diameter of the outlet.

1. ARREST IN OCCIPITO-TRANSEVERSE OR OBLIQUE OCCIPITO POSTERIOR POSITIONVentous applicationAlternative methodsManual rotation followed by forceps extraction: The objectives are first to rotate the head manually until the occiput is placed behind the symphysis pubis and secondly in that position forceps blades are applied. The pelvis should be adequate; the baby is of average size and there is good amount of liquor.Forceps rotation and extraction: In the hands of experts, forceps rotation followed by extraction can be achieved by using Kielland forceps. Its advantages over manual rotation are-No chance of displacement of the head-Aaccidental cord prolapsed is absent and rotation can be done at, above or below the level of obstruction-depending upon the type of pelvis.Caesarean section: If the case is unsuitable for manual rotation specially in the presence of mid pelvic contraction, caesarean section is much safer even at this stage.Craniotomy

2.OCCIPITO-SACRAL ARRESTIf the head is engaged and the occiput descends below the ischial spines, forceps application in unrotated head followed by extraction as face to pubis is an effective procedure. Liberal mediolateral episiotomy should be done. If the occiput remains at or above the level of ischial spines, caesarean section should be considered.

Deep transverse arrestThe head is deep into the cavity; the sagittal suture is placed in the transverse bispinous diameter and there is no progress in descent of the head even after -1 hour following full dilatation of the cervix. causesFaulty pelvic architecture such as prominent ischial spines, flat sacrum and convergent side walls.Deflexion of the headWeak uterine contractionLaxity of the pelvic floor muscles.

diagnosisThe head is engagedThe sagittal suture lies in the transverse bspinous diameter Anterior fontanelle is palpableFaulty pelvic architecture may be detected.

managementBased on fetal condition and pelvic assessmentVaginal delivery is found safe: following methods can be employed,Ventouse Manual rotation and application of forcepsForceps rotation and delivery with Kielland in the hands of an expertVaginal delivery is not safe (with big baby and or inadequate pelvis)- caesarean section.Craniotomy in dead babyManual rotationWhole hand methodHalf hand methodWhole hand methodStep- I (Gripping of the head):In ROP or ROT the left hand and in LOP or LOT, the right hand is usually used. The corresponding hand is introduced into the vagina in a cone shaped manner after separating the labia by two fingers of the other handStep-II (Rotation of the head):By a movement of pronation of the hand, the head is rotated to bring the occiput the external hand form the flank to the midline. This is an essential prerequisite, for anterior rotation of the head. A little over rotation is desirable anticipating slight recurrence of malpositon before the application of forceps.Step III: Application of the forceps: Following rotation, when the right hand is placed on the left side of the pelvis, left blade of the forceps is introduced. When the left hand is used, it is placed on the right side of the pelvis after rotation, as such the right blade is introduced first and the left blade introduced underneath the right blade. 2. Half hand method:In this method, the four fingers and not the thumb are introduced into the vagina. Its advantage over the whole hand method areLess space requiredLess chance to displacement of the head

The rotation is done only by using the right hand. The four fingers are introduced into the vagina and tangnital pressure is applied on the head at the level of diameter of engagement. Thus, the pressure is applied on the side and parietal eminence of the head. In ROP and ROT positions, the fingers are placed anterior to the head and the pressure is applied by the ulnar boarders of the hand. In LOP and LOT positions, the fingers are placed posteriorly and the pressure is applied by the radial boarder of the hand. The force is applied intermittently till the occiput is placed behind the symphysis pubis.

Nursing managementEstablish an IPRCollect history do the physical examination which includes abdominal examination.Monitor the client throughout the labour carefully by monitoring FSH, vital signs and the vaginal examination to know the outcome.Psychological support to the mother.Changing positionDetail explanation of situation and the possibilitiesBack massage to relieve the painMaintain partograph Preparation for deliveryAny deviations found must call a DoctorFamily support must be given.