9.10 Instrumental Delivery

Question 1

What are the main two instruments used for instrumental delivery?

Answer 1

Ventouse suction cup

Forceps

Question 2

What drug should be given after instrumental delivery?

Answer 2

Single dose of co-amoxiclav to reduce maternal infection risk

Question 3

What are some indication for instrumental delivery?

Answer 3

• Failure to progress
• Fetal distress
• Maternal exhaustion
• Control of the head in various fetal positions

Question 4

What choice might increase the risk of instrumental delivery?

Answer 4

epidural analgesia

Question 5

What risk does instrumental delivery present to the mother?

Answer 5

• Postpartum haemorrhage
• Episiotomy
• Perineal tears
• Injury to the anal sphincter
• Incontinence of the bladder or bowel
• Nerve injury (obturator or femoral nerve)

Question 6

What are the 2 key risk and 4 serious risks to the baby of instrumental delivery?

Answer 6

• CEPHALOHAEMATOMA with ventouse
• FACIAL nerve palsy with forceps (and unilateral facial paralysis, bruising, fat necrosis)

Rare serious:

• Subgaleal haemorrhage (most dangerous)
• Intracranial haemorrhage
• Skull fracture
• Spinal cord injury

Question 7

Where is the blood in a cephalohaematoma?

Answer 7

Between skull and periosteum

doesn’t cross suture lines

Question 8

What nerves in the mother can be damaged in instrumental delivery?

Answer 8

Femoral nerve and

Obturator nerve

Question 9

What does injury to the femoral nerve from forceps cause?

Answer 9

• weakness of knee extension
• loss of the patella reflex
• numbness of the anterior thigh and medial lower leg.

Question 10

What does injury to the obturator nerve from forceps or from fetal head in NVD cause?

Answer 10

• weakness of hip adduction and rotation

- numbness of the medial thigh.

Question 11

Name 4 nerves that can be injured in NVD?

Answer 11

Lateral cutaneous nerve of the thigh

Lumbosacral plexus

Common peroneal nerve

(Obturator nerve)

Question 12

How does the lateral cutaneous nerve of the thigh get injured during delivery?
Signs of injury?

Answer 12

Nerve runs under the inguinal ligament.
Prolonged flexion at the hip while in the lithotomy position can result in injury, causing:
- numbness of the anterolateral thigh.

Question 13

How does the lumbosacral plexus get injured during delivery?

Signs of injury?

Answer 13

compressed by fetal head during 2nd stage.
Signs:
- foot drop
- numbness of the anterolateral thigh, lower leg and foot.

Question 14

How does the common perineal nerve get injured during delivery?
Signs of injury?

Answer 14

Gets compressed on the head of the fibula whilst in the lithotomy position.
Signs:
- foot drop and
- numbness in the lateral lower leg

Question 15

Which obstetric nerve injury can cause numbness of anterolateral thigh?

Answer 15

Lateral cutaneous nerve of the thigh

Lumbosacral plexus

Question 16

Which obstetric nerve injury can cause foot drop?

Answer 16

Lumbosacral plexus

Common peroneal nerve

(will lead to a stepping gait)

Question 17

Which nerve has been injured during obstetrics?

• weakness of knee extension
• loss of the patella reflex
• numbness of the anterior thigh and medial lower leg.

Answer 17

Femoral nerve compressed against the inguinal canal during a forceps delivery

Question 18

Which nerve has been injured during obstetrics?

• weakness of hip adduction and rotation
• numbness of the medial thigh.

Answer 18

Obturator nerve compressed by forceps during instrumental delivery or by the fetal head during normal delivery.
(bilateral in 25% of cases)

Question 19

Which nerve has been injured during obstetrics?

- numbness of the anterolateral thigh

Answer 19

Lateral cutaneous nerve of the thigh;
runs under the inguinal ligament.
Prolonged flexion at the hip while in the lithotomy position can result in injury.

(meralgia paraesthetica)

Question 20

Which nerve has been injured during obstetrics?

• foot drop
• numbness of the anterolateral thigh, lower leg and foot.

Answer 20

Lumbosacral plexus; compressed by fetal head during 2nd stage

Question 21

Which nerve has been injured during obstetrics?

• foot drop and
• numbness in the lateral lower leg

Answer 21

Common peroneal nerve; gets compressed on the head of the fibula whilst in the lithotomy position