DR AFROZ KHIZERMCPS TRAINEE

SMH

MALPOSITION This refers to the relationship between

denominator and the pelvis that makes the spontaneous delivery unfavourable,e.g;

Occipito posterior in vertex presentation Sacro posterior in breech presentation Mento posterior in face prsentation

Denominator Most definable peripheral point in the

presenting part,e.g; Occiput in Vertex Sacrum in Breech Mentum in Face Most of the malpositions correct themselves to

normal due to flexion of the head at the atlanto-occipital joint and occiput rotates forwards with additional uterine contactions.This mechanism favours the spontaneous vaginal delivery.

MALPRESENTATION The lowest pole of the fetus that presents to the

lower uterine segment and the cervix is presentation. Presentation other than vertex,i.e; breech,brow,face

or shoulder,they are termed as malpresentation.Causes: 1.Idiopathic 5.Multiple pregnancy 2.Contracted Pelvis 6.Low lying placenta 3.Large baby 7.Preterm labour 4.Polyhydramnios 8.Anomalies of fetus or uterus

Diameters of Female pelvis Transverse

Anterioposterior

Pelvic Inlet 13.5cm 11cm

Mid Cavity 12cm 12cm Pelvic Outlet 11cm

13.5cm

Diameters of Fetal Skull The fetal head is ovoid in shape.There are

different longitudinal diameters that may present in labour depending on the attitude of fetal head.The diameters are;

1. Suboccipito-bregmatic diameter 2.Suboccipito-frontal diameter 3.Occipito-frontal diamter 4.Mento-vertical diameter 5.Submento-bregmatic diameter

SUBOCCIPITO-BREGMATIC DIAMETER----9.5cm Middle of the anterior fontanelle to under surface of the occipital bone.The presenting diameter of the well flexed head in labour.

SUBOCCIPITO-FRONTAL DIAMETER-------10cm From suboccipital region to prominence of forehead.Presents in partially flexed head.

OCCIPITO-FRONTAL DIAMETER-----------11.5cm From root of nose to post fontanelle.A deflexed head presents with this diameter.

MENTO-VERTICAL DIAMETER-------------13cm From chin to furthest point of vertex and is known as brow presentation.This is usually large to pass through normal pelvis.

SUBMENTO_BREGMATIC DIAMETER----9.5cm Chin to anterior fontanelle.Clinically face presentation.

Umbilical Cord Presentation: It is the presence of a segment of umbilical

cord at the cervical OS as the presenting part.

PROLAPSE: It occurs when the membranes

ruptures and segment of cord may be at any level from upper vagina to outside the introitus.

Incidence

-1:500 deliveries –

This is an obstetric emergency because of the risk of cord compression and for occlusion of umbilical arteries going into spasm causing fetal asphyxia.

Aetiology Ill fitting presenting part: -Breech esp. Flexed or footling breech -Transverse lie -Face presentation Multiparity: 80% cases,cord prolapse occur in

multiparous patient as the fetal head remain free until the time of delivery.

Preterm labour: small size baby with copious amount of

liqour. Unduly Long Cord: Artificial rupture of membrane with poorly

applied presenting part.

DiagnosisA loop of cord is felt in vagina or may be seen

at the vulva.

Fetal heart irregularities especially a variable deceleration pattern on CTG without obvious cause strongly suggests occult cord prolapse.

Can also be diagnosed on Ultrasound.

MANAGEMENTIts an emergency situation and an

indication for immediate Caesarean Section if baby is alive and vaginal delivery cannot be effected immediately.

Aim of management is to prevent the presenting part from occluding the cord. This can be done by following ways..

1...Displacing the presenting part by putting hand in vagina to avoid pressure on the cord.

2...Placing patient in SIM’S POSITION

3..KNEE ELBOW POSITION

4...Infusion of 500ml warm saline in bladder through 16 size catheter may be an alternative.

The cord is kept in the vagina to keep it warm and moist to prevent arteries going into spasm.

Along all these measures,assistants should at the same time:

Establish IV access with 16 G cannula Take blood for Haemoglobin and X-match Give an H2 receptor agonist Call anaesthetist and peadiatricion

When the fetus is alive and cervix is fully dilated,immediate vaginal delivery should be made by using forceps if presenting part is descending with each contraction.

Vaginal delivery should be done with full preparations for Caesarean Section.

If fetus is dead ,labour is left to continue untill eventually vaginal delivery takes place.

PreventionDuring antenatal period patients should be

counselled to report hospital if leaking occurs,with or without contractions.

Amniotomy should ONLY be done when the presenting part is fixed.

REFERENCES

Dewhurst’s textbook of Obstetrics & Gynaecology(Eighteenth Edition)

Obstetrics By Ten Teachers(Seventeenth Edition)

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