Abnormal labour

Abnormal labour

Dr: Hayder Al-Shamma’a

Objectives

The student must be able to define abnormal labour
Should be able to list the types
Should be able to list the risks of abnormal labour on the mother and fetus
Should understand the mechanism of labour for each type
Should be able to diagnose abnormal labour

Objectives continue

Able to manage first stage of labour
Know the rational for the management
Able to list the management of the second stage

types

I :- Malposition and Mal-presentation of the head ( occipito-posterior, face presentation ,brow presentation)
II:- Breech presentation
III:- Shoulder presentation(Transverse lie)


Risks of abnormal labour
Abnormal labour carries increased risks to the mother and the fetus more than normal labour , specially if the labour is attended by an inexperienced personel

Maternal risks of abnormal labour

• prolonged labour
• Infection
• Obstructed labour
• Anesthesia
• Traumatic delivery
• Hemorrhage
• DVT
• Pressure necrosis and fistula
• death

Fetal risks

• Cord prolaps
• Hypoxia
• Infection (chorio-amnionitis , pneumonia)
• Traumatic injuries
• Meconium aspiration (pneumonitis)
• death


Malposition & mal-presentation of the fetal head
• Occipito-posterior position
• Face presentation
• Brow presentation

Labour in occipito-posterior position

The denominator is the occiput

The occiput occupy the posterior part of the female pelvis ie. occiput near the sacrum

Occipito-posterior

Causes of O. P.

Anthropoid pelvis favor direct o.p position
Android pelvis favor oblique o.p. position
Anteriorly situated placenta
gross pendulous abdomen
Congenital malformations
Abnormal extensor tone
Polyhydramnious
Prematurity
Multiple pregnancy


Diagnosis of occipito posterior
By abdominal exam.
• Flat lower abdomen below the umbilicus
• easy to feel Fetal limbs anteriorly
• difficult to feel the Fetal back
• Head not engaged
• Fetal heart at the flanks

Diagnosis of occipito posterior

By pelvic exam.
• High presenting part
• Bulging sausage shaped membranes
• Or early rupture of membranes (cx.less than 3cm)
• Easy to feel the anterior fontanel behind the pubic symphysis
• Difficult to feel the posterior fontanel near the sacrum
• ear directed posteriorly (in excessive caput & edema)


Mechanism of labour in O.P.
Engagement in ROP (ROP 3times than LOP)
Engaging diameter is suboccipito-frontal 10.5 cm if the head well flexed .
Or occipito-frontal 11.5 cm if the head deflexed (both larger than normal OA suboccipito-bregmatic 9.5 cm)
This gives an oval shaped presenting part not fit well on the cx. Of larger dimentions

Mechanism of labour in O.P.

Internal rotation:- if the head well flexed the occiput will touch the pelvic floor first and rotated anteriorly 3/8th of a circle 135˚ and become occipito-anterior and the mechanism then continue as in OA. But it takes longer time to rotate
This occurs in 70% of cases

Mechanism of labour in O.P.

If the head is deflexed :- the sinciput touches the pelvic floor first so rotates anteriorly and the occiput rotates posteriorly through 1/8th of a circle (45˚) short rptation giving direct occipitoposterior
The mechanism differs , descent continues and the head delivers by a combination of flexion first, followed by extention
The emerging diameter is occipito-frontal of 11.5 cm causing great distension at the vulva and perineum and perineal tears may occur unless episiotomy performed
Occurs in 10% of cases

Mechanism of labour in O.P.

Arrest of rotation at lateral position (right occipito-lateral or left occipito-lateral)
No mechanism of labour
Deep transverse arrest
Need assisted delivery
Occurs in 20% of cases


Features of labour in O.P.
• Slow progress (slow cx. dilatation, descent, rotation)
• Backache is more
• Incoordinate uterine contraction
• Early rupture of membranes
• Higher chance for cord prolaps
• Higher chance for infection
• Higher chance for perineal laceration
• Excessive moulding of the head may cause tentorrial tear

Treatment of O.P.

• Before the onset of labour , no attempt for correction
• During first stage of labour
• Correction of malposition cannot be done
• Observation of uterine contraction, cx dilatation, descent,and use partogram
• Continuous fetal heart monitoring
• Due to increased risk for operative delivery and anesthesia , give nothing by mouth, only occasional sips of water
• Maintain maternal hydration by iv fluid
• Oxytocin infusion is often indicated to correct incoordinate uterine contractions

Treatment of O.P.

Cesarean section is indicated in first stage in the following conditions
• Failure to progress in spite of good uterine contractions for 3 hours
• Fetal distress
• Maternal distress


Treatment of O.P.
Treatment in second stage
Mistaken diagnosis of 2nd stage is not uncommon, the patient have urge to pushdown before full dilatation (pressure effect of the large occiput on the pelvic plexus
p/v exam is essential to confirm the diagnosis

Rx of 2nd stage continue

p/v to assess degree of deflexion
Determine excessive molding
Determine caput succidanium
If detect that , spontaneous labour is unlikeley to occur
Pain relieve is essential in O.P.
Epidural analgesia , pethidine

Need assisted delivery

Fetal distress
Maternal distress
Failure to progress
Deep transverse arrest

Assisted delivery

• Oxytocin
• Manual rotation with or without forceps extraction
• Forceps rotation (Kielland forceps)
• Vacuum extractor
• Cesarean section


Manual rotation
Correction of malposition by manipulation with the hand under epidural anesthesia
Disadvantage need anesthesia, hand take additional space , may cause trauma, pulling is not feasible

Kielland forceps rotation

Same disadvantages but ,can pull the head, also it need a great deal of experience

Vacuum extraction ( Vantouse , Kiwi)

Advantages
Applied without anesthesia, not take extra space, easy to use minimal skills

No comment !!!!!!

No comment !!!!!

Face presentation
The head is fully extended
1/300 deliveries
Causes : same as O.P.
The denominator is the mentum (chin)
Mento-posterior no mechanism of labour the chest try to enter the pelvis at the same time with the head (sternobregmatic 16-18cm)

Mechanism of labour in mento anterior

Engagement in mentolateral ML or RMA
Engaging diameter is the submento bregmatic 9.5 cm
Descent occurs slowly
Rotation occur late in 2nd stage
Engagement occur at +2 or +3 station
Delay in 2nd stage due to oblique line of thrust from the back to the head
The face deliver by flexion
Emerging diameter is the submentovertical 11cm

Diagnosis of face presentation

Abdominal findings:- Longitudinal lie, cephalic , a groove can be felt between the head and back , the head is high
p/v feel the chin, mouth, jaws, nose, orbital ridge

management

Exclude CPD, hypertension , placenta previa, other risk factors , estimated fetal wt 3.5kg
If any of the above cesarean section safer
Manage as in case of O.P.

Brow presentation

1/1000
Incomplete extension
It is usually a transient presentation , either change to vertex or to face
Causes as face
Diagnosis
On abdominal exam as in face but the groove is less prominent
p/v :- feel ant. Fontanel, orbital ridge, roote of the nose, eyes, but not the chin

Mechanism of labour in brow

No mechanism of labour . The engaging diameter is the mentovertical 14 cm so cesarean section is indicated in persistent brow

Thank you