FAILURE TO PROGRESS AND SHOULDER DYSTOCIA

Question 1

What are the three factors that determine the rate of progression in labour?

Answer 1

Passages

Passenger

Power

Question 2

What are the factors associated with the passages (bony pelvis and soft tissue) that might lead to labour failing to progress?

Answer 2

Abnormal shaped pelvis
Cephalopelvic disproportion
Uterine/cervical fibroids
Cervical stenosis
Circumcision

Question 3

What are the factors associated the fetus (passenger) that might lead to labour failing to progress?

Answer 3

Fetal size - macrosomia
Fetal abnormality
Fetal malpresentation
Fetal malposition

Question 4

What are the factors associated with power or push that might lead to labour failing to progress?

Answer 4

Lack of coordinated regular strong uterine contractions

Question 5

What are the normal rates of progression in terms of cervical dilation?

Answer 5

Primip - 0.5 - 1 cm/h

Multip - 1 - 2 cm/h

Question 6

What are the causes of a woman having abnormal shaped pelvis, which might lead to her labour failing to progress?

Answer 6

Conditions:
Osteogenesis imperfecta
Ectopia vesicae
Dislocation of the hip at birth

Acquired:
Kyphosis of thoracic or lumbar spine
Scoliosis of spine
Spondylolisthesis
Pelvic fractures
Rickets/osteomalacia
Poliomyelitis in childhood

Question 7

What conditions lead to macrosomia?

Answer 7

Diabetes

Hydrops fetalis - rhesus isoimmunization or parvovirus infection

Question 8

What vertex presentations might lead to failure to progress in labour?

Answer 8

Occipito-posterior position

Occipito-transverse position

Question 9

What proportion of vertex presentations will be occipito-posterior?

Answer 9

20%

Question 10

How do we manage a fetus presenting in the occipito-posterior position?

Answer 10

Most will rotate spontaneously

Those that don’t will either still deliver without problems, or can be turned manually or with an instrument.

Question 11

What properties of contractions suggest inefficient uterine action?

Answer 11

Uncoordinated contractions

Fewer than 3-4 in 10 min

Lasting less than 60s

Delivering a pressure of less than 40 mmHg (recorded using a pressure catheter)

Question 12

How do we manage a patient whose labour is failing to progress due to inefficient contractions?

Answer 12

Artificial rupture of membranes

Use of IV syntocinon - caution must be exercised in multiparous patient

Question 13

How does artificial rupture of membrane help labour along?

Answer 13

Thought to release prostaglandins.

Question 14

Why is it important to monitor fetus after administration of IV syntocinon?

Answer 14

If contractions become too frequent this can reduce oxygen exchange in the placental bed and lead to fetal hypoxia.

Question 15

What might prompt a physician to consider delivery by caesarian section?

Answer 15

Presence of good contractions over several hours without significant progression in terms of cervical dilatation

Question 16

What is shoulder dystocia?

Answer 16

This is when the head has been delivered but the shoulders (specifically the anterior shoulder) is unable to pass into the pelvic inlet.

Question 17

What are the complications of shoulder dystocia?

Answer 17

Erb’s palsy

Hypoxia due to cord compression whilst in the vagina

Question 18

What is Erb’s palsy?

Answer 18

Damage to nerve roots C4, C5 and C6 leading to paralysis of the arm

Question 19

How is shoulder dystocia managed?

Answer 19

Do not pull on the head - leads to damage of brachial plexus

Lie patient flat and try following steps until they work:

Put them in McRoberts position, if this does not work then

Apply suprapubic pressure to dislodge and deliver anterior shoulder, if this does not work then

Use internal rotation techniques to try and rotate anterior shoulder from under pubic symphysis

Deliver posterior arm

Question 20

What is McRoberts position?

Answer 20

Hyperflex the mother’s knees onto her abdomen with her hips apart and apply suprapubic pressure