Birth Injuries

Question 0

Cephalhaematoma

Answer 0

Subperiostal swelling on fetal head, boundaries therefore limited by the individual bones margins (commonest over parietal bones).

It is fluctuant.

Spontaneous absorption occurs but may take weeks. May cause or contribute to jaundice.

Question 1

Moulding

Answer 1

A neutral phenomenon where the skull bones override each other to reduce the diameter of the head.

If no moulding, skull bones felt separately.
If slight moulding, bones touch, then override but can be reduced.
More moulding, bones override so much that they cannot be reduced.

Excessive moulding during labour indicates cephalo-pelvic disproportion and can result in intracranial damage.

Question 2

Caput succedaneum

Answer 2

Oedematous swelling of the scalp, superficial to the periosteum (therefore not limited in its extent).

Result of venous congestion and exuded serum caused by pressure against the cervix and lower segment during labour. Swelling is therefore over the presenting part.

Gradually disappears over few days.

If ventouse extraction is used a large caput (called a chignon) is formed under the gap.

Question 3

Erb’s palsy

Answer 3

May result from difficult assisted delivery eg shoulder dystocia (therefore risk x10 in diabetic).

Baby’s arm is flaccid and hand is in porter’s tip posture.

Damage is to suprascapular, musculocutanous and axillary nerves.

Exclude a fractured clavicle and arrange physiotherapy. If not resolved by 6 months, the outlook is poor.

Question 4

Subaponeurotic haematoma

Answer 4

Blood lies between aponeurosis and periosteum.

As the haematoma is not confined to the boundaries of one bone, can be large enough to result in anaemia or jaundice.

Associated with vacuum extractions.

Question 5

Skull fractures

Answer 5

Associated with difficult forceps extractions.

Commonest over parietal or frontal bones.

If depressed fracture with neurological signs may need to get bone elevated by neurosurgeon.

Question 6

Intracranial injuries

Answer 6

Intracranial haemorrhage is especially associated with difficult or fast labour, instrumental labour, and breech delivery. Premature babies more vulnerable.

Excessive moulding reduces buffering effect of CSF.

Always check babies platelets. Treatment is expectant and supportive.

Anoxia may cause intraventricular haemorrhage.
Asphyxia causes intracerebral haemorrhage and may result in cerebral palsy.
Extradural, subdural and subarachnoid haemorrhages can all occur.

Question 7

Episiotomy and perineal tears

Answer 7

Labial tears - common, heal quickly and do not usually need suturing.

First degree tears

• superficial, do not damage muscle
• suture unless skin edges well apposed to aid healing.

Second degree tears

• lacerations include perineal muscle
• repair with reabsorbable sutures

Third degree tears

• involves anal sphincter muscle
  
  • 3a: external anal sphincter thickness 50% torn
  • 3c: both external and internal anal sphincters torn.

Fourth degree tears
- rectal mucosa involved

1st and 2nd degree managed/sutured by midwife. 3rd and 4th degree repaired by experienced surgeon.

Episiotomy

• performed to enlarge outlet eg to hasten delivery of distressed delivery, instrumental or breech delivery, to protect premature head, to prevent third degree tears.
• cut medio-laterally towards ischial tuberosity

Question 8

Dystocia

Answer 8

Difficulty in labour.

Due to 3P’s:

• passages - may be soft tissue (eg fibroid or cervical dystocia after cervical biopsy or genital mutilation) or bony obstruction
• passenger - owing to large baby or abnormal presentation
• propulsion - due to uterine powers

Question 9

Cephalopelvic disproportion

Answer 9

If diameters unfavourable and/or head is big.

Question 10

The pelvis

Answer 10

Ideal pelvis has a round (gynaecoid) brim.

15% have long oval (anthropoid) brim.

5% have very flat brim (platypelloid) brim - less favourable.

Question 11

Presentation and lie

Answer 11

Cephalic presentation are less favourable the less flexed the head is.

Transverse lie and brow presentations always need c-section.

Face and OP presentations may deliver vaginally but more likely to fail to progress.

Breech presentation is most unfavourable if fetus > 3.5kg

Question 12

Shoulder dystocia

Answer 12

Inability to deliver shoulders after head has been delivered.

Occurs in 0.6%. Brachial plexus injuries occur in 4-16% of which 10% are left with permanent disability.

The danger is death from asphyxia - speed is vital as cord is usually squashed at pelvic inlet.

Management:

• mcroberts position (hyperflexed lithotomy) successful in 90%
• suprapubic pressure with steady traction to fetal head
• if fails, check anterior shoulder under symphysis, rotate if need to
• if fails put posterior shoulder anteriorally
• try mother on all fours
• reverse movements of labour and try c-section
• if baby dies prior to delivery, cutting through both clavicles with strong scissors assists delivery (cleidotomy).