MALPRESENTATION

•	Face presentation.
•	Shoulder presentation. 
•	Brow presentation.
•	Breech presentation.

Face presentation

1.	Occurs when the normal attitude of flexion is absent:

a.	The head is extended and the face of the fetus presents at the pelvic brim.

b.	Incidence: 1:500 labors.

2.	Positions:

a.	Mento-anterior: 2x common as MP.

b.	Mento-posterior.

c.	Left.

d.	Right.

3.	Abdominal examination: occiput is unduly prominent with a marked hollow followed by the fetal back.

4.	Vaginal examination:

a.	early in labor: high presenting part with elongated bag of fore-waters.

b.	later: face identified by the mouth, nose, chin and orbital margins. 

5.	Mechanism of labor:

a.	MA:

i.	the presenting diameter is a submento-bregmatic measuring 9.5cm.

ii.	engagement of fetal head is late and progress in labor is frequently slow.

iii.	descends with chin undergoing internal rotation at the pelvic floor – chin lies under pubic arch and head is borne by flexion.

b.	MP: 

i.	usually rotates to MA through 135 degrees.

ii.	if not, it gets impacted and assistance is usually necessary.

6.	Management:

a.	MA: delivery vaginally.

b.	MP: if no spontaneous rotation to MA, then LSCS.

Shoulder presentation

1.	Occurs in transverse lies:

a.	Shoulders presents at brim when membranes rupture, the arm prolapses.

b.	Incidence: 1:300 labors.

2.	Positions:

a.	Dorso-anterior: more common.

b.	Dorso-posterior.

3.	Abdominal examination:

a.	Uterus symmetrical.

b.	Fundus lower than expected and breadth increased.

c.	Pelvis empty and head felt in iliac fossa.

4.	Vaginal examination: arm felt.

5.	Course of labor:

a.	Very premature: fetus born doubled up.

b.	Mature baby: delivery is impossible.

6.	Management:

a.	If the woman presents in labor with a shoulder presentation, no attempt should be made to perform external version even if the membranes are intact as the uterine tone may be high and the fetus could be damaged.

b.	Early membrane rupture is common with shoulder presentation; if this occurs, vaginal examination should be immediately performed to exclude prolapse of the cord.

c.	Prevention is the proper management of unstable lies.

d.	LSCS.

Brow presentation

1.	Very large presenting diameter: mento-vertical – 13.3cm.

2.	Incidence: 1:2000 labors.

3.	Vaginal examination:

a.	High presenting part, cannot be made to engage.

b.	Palpating the anterior fontanelle, supra-orbital ridges and nose.

4.	Mechanism of labor:

a.	It is impacted at the brim and therefore there is no mechanism of labor.

b.	Labor can only progress if it converts to vertex or face presentation. 

c.	X-ray to confirm diagnosis.

d.	If this presentation persists, delivery must be achieved by LSCS.

Breech presentation

1.	Introduction:

a.	Incidence: 3-4%.

b.	Perinatal mortality is 4 – 5 times higher than NVD.

c.	It may be associated with maternal or fetal abnormality but usually no cause can be elicited.

d.	Prematurity is one of the most common causes and this should be excluded in a patient with a breech presentation. 

2.	Types:

a.	External / frank: both legs and hips are flexed.

b.	Caudate: both legs at hips are flexed – presents with buttocks, genitalia and feet.

c.	Footling: presents with one foot.

3.	Etiology:

a.	Uterine:

i.	multiparity.

ii.	contracted pelvis.

iii.	congenital malformations of uterus.

b.	Fetus:

i.	prematurity.

ii.	multiple gestation.

iii.	congenital malformations: hydrocephalus, anencephaly.

c.	Placenta and liquor:

i.	placenta praevia.

ii.	hydramnios.

d.	Recurrent breech:

i.	contracted pelvis.

ii.	congenital uterine malformations.

4.	Antenatal management:

a.	Ultrasound:

i.	confirm diagnosis.

ii.	find causes of breech, including dating the fetus.

iii.	size of fetus.

iv.	type of breech and attitude.

b.	External cephalic version (ECV):

i.	may reduce the incidence of breech presentation at birth and decrease the risks and complications of a vaginal breech delivery.

ii.	if there are no contraindications, it may be performed between 34 and 36 weeks.

iii.	it may be performed after 37 weeks gestation with IV tocolytics.

iv.	the fetal heart has to be monitored before and after the procedure. 

v.	any significant change in FHR following the procedure may warrant an emergency LSCS.

c.	A subsequent ultrasound will confirm whether the procedure has been successful: follow-up and spontaneous labor is awaited with the aim of a normal vaginal delivery.

d.	When ECV is unsuccessful, the decision must be made regarding the mode of delivery.

e.	Assessment clinically and on X-ray pelvimetry:

i.	fetal weight.

ii.	adequacy of pelvis.

iii.	position and attitude of fetus.

f.	Pre-requisites for vaginal breech delivery:

i.	EFW is between 1.5 and 3.5 kg. 

ii.	presentation is extended or flexed.

iii.	no evidence of fetopelvic disproportion and fetal abnormalities. 

5.	Vaginal breech delivery is planned if the following criteria are fulfilled:

a.	Gestational age at delivery > 33 completed weeks.

b.	EFW < 3700g.

c.	Lateral pelvimetry: anteroposterior diameter of inlet > 11.5cm and good sacral curve.

d.	Adequate clinical pelvimetry.

6.	LSCS is performed on the following indications:

a.	Expected birthweight > 3700g.

b.	Inadequate pelvis.

c.	Hyperextension of fetal neck. 

7.	Labor:

a.	An experienced obstetrician and paediatrician should be available for all breech deliveries.

b.	Position of the fetal head should be confirmed with ultrasound in LW to exclude hyperextension.

c.	Blood for group and cross match.

d.	Avoid induction of labor in breeches except on strict indications.

e.	Risk of cord prolapse is increased in breech presentation, especially in complete and footling breeches.

f.	Frequent assessment of progress: continuous CTG in 1st and 2nd stage of labor.

8.	Delivery

a.	Delivery of buttocks: in most circumstances full dilatation and descent of the breech will have occurred naturally.

b.	Delivery of the legs and lower body: 

i.	if the legs are flexed they will deliver spontaneously.

ii.	if extended they may need to be delivered using Pinard’s manoeuvre: this entails using a finger to flex the leg at the knee and then extend at the hip.

c.	Delivery of shoulders:

i.	the arms and shoulders are delivered by hooking first the anterior and then the posterior arm from under the symphysis pubis.

ii.	Loveset’s manoeuvre: gently ‘rocking’ the body with downwards traction.

d.	With delivery of the shoulders, the breech is allowed to hang for at least one minute, so that the weight of the baby will allow the head to flex as it enters the pelvis.

e.	Delivery of head:

i.	the head is delivered using the Mauriceau-Smellie-Veit manoeuvre: the baby lies on the obstetrician’s arm with downward traction being levelled on the head via a finger in the mouth and one on each maxilla.

ii.	delivery occurs with first downward and then upward movement.

iii.	if this manoeuvre proves difficult, then forceps need to be applied.

iv.	an assistant holds the baby’s body aloft whilst the forceps are applied in the usual manner.

Complications

1.	Prolapse of the cord: this is common with a footling presentation and to a lesser extent with a flexed breech presentation.

2.	Difficulty in delivering the shoulders: damage can be caused to the brachial plexus of the fetus or to the liver.

3.	Difficulty delivering the head: 

a.	Sudden uncontrolled delivery of head: result in intracranial bleeding due to a tear of the tentorium.

b.	Delay in delivery of head: result in prolonged compression of the umbilical cord and asphyxia.

Preterm breech

1.	If the patient is in advanced labor, she should be allowed to progress and anticipate vaginal delivery.

2.	If the fetus is alive, the mother is in early labor and EFW is between 1000 and 1500g, LSCS should be considered.

3.	If the mother is not in labor, steroids should be administered and labor inhibited for 24 to 48 hours.