Birth Injuries to the Baby

The passage from the safety of the uterus to the outside world is a dangerous journey:

• The skull has to mould to facilitate passage through the pelvis and there may be cephalo-pelvic disproportion (CPD) - a mismatch between the size of the fetal head and the capacity of the maternal pelvis. It may represent a large head in a normal pelvis or a normal head in a restricted pelvis.
• Malposition increases risk whilst malpresentation demands Caesarean section.
• Contractions tax the reserve of the placenta.
• The lungs and circulation undergo great changes.

Difficulties in delivery may compound the situation. Delivery may need to be expedited because of fetal distress.

Injuries may be caused by a combination of mechanical trauma and hypoxia but this article will concentrate on mechanical injuries.

Birth injuries may be minor and transient but they can produce serious and permanent effect as well as being fatal. It used to be assumed that most cases of cerebral palsy were due to obstetric mismanagement but nowadays the figure for those caused by obstetric trauma is put at around 5%.¹

Figures for major (but not fatal) birth trauma in the UK are not apparently available. Although for fatal outcomes the national intrapartum-related confidential enquiry reported and reviewed 37 cases in which birth weight was in excess of 2500 grams for the year 1994 -1995.²
Problems are difficult deliveries, instrumental deliveries and poorly judged persistence at vaginal delivery:
American and Canadian papers have found that birth trauma occurred in 2% deliveries and brachial plexus injury in 0.5 to 2.0 per 1,000 live births.^3,4

Risk factors

Risk factors for birth trauma include:

• A large infant (especially if weighs more than 4,500g)
• Cephalopelvic disproportion
• Instrumental delivery (especially midcavity forceps or ventouse delivery for deep transverse arrest)
• Breech delivery (advantages of elective LSCS for breech presentation are not clear)⁵
• A premature baby (small head and incompletely formed skull - precipitate delivery can cause "champagne cork popping" - risking intracranial haemorrhage.)
• Shoulder dystocia (a skilled midwife or obstetrician will reduce the risk)⁶

Other risk factors include:

• Primagravida (untried pelvis)
• Very short labour may represent precipitate delivery of a premature baby
• Very long labour may indicate CPD
• Oligohydramnios
• Congenital abnormalities (especially if enlarged head or macrosomia)

Cephalohaematoma

• Bleeding between the periosteum and skull causes a haematoma, usually in the parietal region and sometimes the occipital region. Spread is restricted by suture lines that are adherent.
• Blood loss can cause anaemia and even hypotension.
• As the haematoma resolves, breakdown of haemoglobin can cause hyperbilirubinaemia that may need treatment.
• An underlying skull fracture is found in up to 20% cases. If it is thought to be depressed, CT or MRI imaging is required.
• Spontaneous remission may take weeks and there is sometimes residual calcification.
• A haematoma may rarely become infected.
• Consider the possibility of a coagulation defect.

Subgaleal haematoma

• Bleeding between the periosteum and scalp is usually associated with use of ventouse extraction.⁷
• 90% follow ventouse extraction and 40-50% overlie a skull fracture or brain haemorrhage.⁸
• It usually appears within 12 to 72 hours of birth as a soft, fluctuant mass within the scalp, especially over the back of the head.
• It can spread slowly and be unnoticed and present as hypotension.
• The spread is not restricted by suture lines.
• As with cephalohaematoma, management is conservative but check for anaemia.

Caput succedaneum

• This is a poorly-defined, subcutaneous collection of serosanguinous fluid that spreads over suture lines and the midline.
• It is very common after prolonged labour.
• It does not cause significant problems and needs only to be monitored.

Cuts and abrasions

• These may result from operative delivery, including cutting the baby with the scalpel blade at LSCS. Great care is needed in cutting the last layer of the uterus, even in an emergency.
• Cuts need closing and dressing. Topical antibiotic may be indicated.

Subcutaneous fat necrosis

• This is not usually apparent at birth.
• Some time later, irregular, hard, subcutaneous plaques appear with overlying dusky red-purple discoloration.
• They occur on the extremities, face, trunk or buttocks having been caused by pressure during delivery.
• There is no treatment and they should resolve but sometimes there is calcification.

The majority of these are Erb's palsy involving the upper part of the brachial plexus. The underlying problem is usually injudicious traction when the anterior shoulder is trapped (shoulder dystocia).^9,10 Only 10% involve the whole brachial plexus. Associated injuries include:

• Fractured clavicle (10%)
• Fractured humerus (10%)
• Subluxation of cervical spine (5%)
• Cervical cord injury (5-10%)
• Facial palsy (10-20%)
• Occasionally, there is phrenic nerve paresis

Erb's palsy

• There is damage to the C5, C6 segments of the brachial plexus.
• It produces loss of motion of the shoulder with a limp arm, adducted and internally rotated. The elbow is pronated and extended with wrist flexed.
• The grasp reflex is normally maintained but Moro, biceps and radial reflexes are lost.

The position of the hand is said to be reminiscent of a porter who is turning away but is holding out his hand behind him for a tip.

Klumpke paralysis

This is much less common that Erb's palsy in infants.

• It is due to damage of the nerves of segmental origin C7, C8, T1 in the brachial plexus.
• It causes paralysis with weakness of the hand and loss of grasp reflex.
• Horner's syndrome may be seen if there is T1 damage.

Management

• Most cases of brachial plexus injury resolve spontaneously within 4 months, but it can take up to 2 years.
• X-rays to exclude fractures and examination for phrenic nerve paresis are required. Further investigations include MRI, electromyography, nerve conduction studies and CT myography.
• To prevent contractures, immobilise the arm across the upper abdomen for 7 days then start physiotherapy using wrist splints.
• Consider surgery if movement is not returning after 3 months and electrophysiology results suggest a poor prognosis.¹¹

Cranial nerve and spinal cord injuries result from hyperextension, traction, and overstretching with simultaneous rotation. Neurapraxia will resolve swiftly but complete nerve or cord transection is a much more serious matter.

• Central damage to the facial and vagus nerves cause an asymmetrical face on crying with swelling and smoothness of the affected side and drooping of the side of the mouth.
• Peripheral damage causes paralysis to the eye, forehead or mouth only.
• Most cases soon start to recover but full recovery may take months.
• The eye must be protected with a covering and synthetic tears.
• If there is no improvement after 7 to10 days, investigation is required.
• Phrenic nerve damage can cause paralysis of half of diaphragm leading to breathing difficulties with significant mortality. Ultrasound or X-ray shows an elevated hemidiaphragm but this may be absent in the early stages. Screening may show immobility.
• 80% of phrenic nerve palsies are on the right side, 10% on the left side and 10% are bilateral.
• There is a mortality of 10 to 15% for unilateral lesions rising to 50% for bilateral ones.

• Unilateral paralysis often presents with a hoarse cry or stridor and may affect swallowing.
• Bilateral damage causes severe respiratory problems.
• Diagnosis is by laryngoscopy to exclude other causes of the symptoms.
• Recovery usually occurs after 4 to 6 weeks but can take up to a year.

• Damage to the spinal cord often results in stillbirth or babies who die soon after delivery due to an inability to breathe.
• Ventilation may be life saving but if the lesion is not a temporary neuropraxia there will be later agonising decisions about turning off the ventilator.
• Those that survive are weak and often develop spasticity.
• Diagnosis is by MRI or CT myelography.
• Treatment is supportive.

Clavicle

• Fractured clavicle is common and presents with apparent paralysis.
• Palpation may show crepitus, uneven bone and muscle spasm.
• It heals within 7 to 10 days with the arm immobilised.
• Confirm the diagnosis by x-ray.
• Look for other damage.

Arm and leg bones

• Fracture may be heard during delivery.
• It presents with absence of normal movement of the limb with swelling becoming apparent later.
• Confirm with X-ray.
• Treat with 8 to 10 days of splinting or reduction and casting if displaced.
• Check for radial nerve damage in arm fractures.

• This presents with shock, pallor and a distended abdomen, possibly bluish in colour.
• Check for anaemia.
• Diagnose with paracentesis.
• Causes include hepatic laceration and rupture of spleen, so this is serious.

Good maternity care will reduce the risk of an adverse outcome to both mother and child.

Caesarean section

Fear of fetal damage and the vast cost of litigation have led to an increasing rate of Caesarean section that is now around 24% in the UK as a whole with significant geographical variation.^12,13,14,15 In some parts of the world the figure is rather higher. There is dispute as to whether the current rising rate of Caesarean section has gone too far. The World Health Organisation has suggested that in developed countries the figure should not be above 15%. Skills in the use of Kielland's forceps and assisted breech delivery are being lost as LSCS is more readily undertaken.

Prematurity

A major contributor to perinatal mortality and morbidity is prematurity.¹⁶ Prevention of this is important and analysis of figures for outcomes should exclude babies below a certain weight.
Weight is a more reliable parameter than gestational age.

The rising rate of Caesarean section may be reducing fetal trauma, but other outcomes are less clear. Electronic fetal monitoring also has a very high rate of false positives.¹ The literature must be interpreted with caution in terms of making valid comparisons.

Obstetric intervention is a difficult subject that can readily arouse more passion than reason, but in reality an evidence based management scheme is very difficult to produce. Physical injuries may well be caused by injudicious delivery, but ready resort to LSCS should not be seen as an alternative to obstetric skills.