Oxford Handbook of Midwifery (129 page)

Jaundice lasting beyond 10 days may indicate:

ABO incompatibility

The incidence is 1:5 births. A mother who is group O and whose baby is group A or B has naturally occurring anti-A or anti-B lysins (antibodies), which destroy the fetal RBCs, leading to newborn jaundice.

G6PD deficiency

This is an X-linked recessive condition. G6PD maintains the integrity of the RBC membrane, so a lack of this enzyme leads to excessive haemo- lysis. This condition can be triggered by infection or sulphonomides.
³

Breastfeeding jaundice

the conjugated bilirubin in order to return unconjugated bilirubin via the placenta to the maternal circulation for excretion by the mother. The fetus is not able to excrete it through its bowel until after birth. Breastfed babies excrete less bilirubin in their stools,

keeping conjugated bilirubin in the intestines for longer, thus increasing the chance that the B-glucuronidase will unconjugate it before if is excreted.

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Care of the newborn

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Assessment of infants with jaundice

All infants are at risk of jaundice. Factors that increase this risk must be identified.

Factors that increase the risk

• Feto-maternal blood-group incompatibility (haemolysis).
  
• Birth trauma (RBC destruction and increased bilirubin production)
  
• Delayed cord clamping increases the RBCs in the baby’s circulation.
  
• Congenital abnormalities of the gastrointestinal tract.
  
• Delayed passage of meconium /delayed feeding (increases enterohepatic shunting).
  
• Sepsis (leads to RBC destruction and altered hepatic clearance).
  

  Other risk factors
  

• Low birthweight
  
• Prematurity
  
• PROM
  
• Increased weight loss, delayed feeding, and dehydration
  
• Swallowed/sequestered blood from trauma, cephalic haematoma, and surgery.
  ¹
  ,
  3
  

  Problems that interfere with bilirubin metabolism
  

• Hypoxia
  
• Asphyxia
  
• Hypoglycaemia
  
• Hypothermia.
  

  Preventative strategies
  

  •
  Give Rh D immunoglobulin to Rh D-negative mothers within 72h of delivery of each baby.
  

• Avoid trauma in labour.
  
• Prevention of hypothermia.
  
• Prevent hypoxia and hypoglycaemia.
  
• Early feeding/increased frequency of breastfeeding.
  ¹
  ,
  3
  

  Examination
  

  Assess:
  

• Skin and sclera
  
• Activity. Note:
  
• Birth trauma
  
• Length of gestation.
  

  NICE
  ⁴
  now recommends that all babies who are more likely to develop jaundice in the first 72h should be assessed at every opportunity, in order to identify those needing intervention.
  

• Measure and record bilirubin level within 2h of all babies with suspected jaundice especially in the first 24h of life.
  ⁴
  
• Continue to measure the bilirubin level every 6h for all babies with suspected or obvious jaundice.
  ⁴
  

  NEONATAL JAUNDICE
  

  607
  

>250mmol/L check the result by measuring the serum bilirubin.
⁴

Investigations

Laboratory estimation of serum bilirubin levels is required for all ill term and premature infants. The levels are reported as total bilirubin and the direct (conjugated) component.

Investigate cases of prolonged jaundice for liver function and thyroid prob- lems. To detect spherocytes and a diagnosis of congenital spherocytosis, carry out an RBC smear.

Total bilirubin

Blood-group testing

Direct Coombs’ test

This is a measure of antibody-coated blood cells. It is a direct measure of
the amount of maternal antibody coating the infant’s RBCs.

Indirect Coombs’ test

This measures the effects of a sample of the infant’s serum, thought to contain antibodies, on the RBCs of an unrelated adult. If antibody is present, the components will interact and coat these adult RBCs, giving a
positive indirect result
.

Kleihauer’s test

This detects the presence of fetal blood cells in the maternal circulation. This normally occurs during separation of the placenta from the uterus following delivery of the baby. The presence of fetal cells in the maternal circulation indicates a risk of antibodies being formed if the mother is Rh negative and the fetal blood cells are rhesus positive.
^1,3

Management

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Care of the newborn

608

Phototherapy

The light used in phototherapy reduces bilirubin levels by:

• Photoisomerization
  , which converts indirect bilirubin to water-soluble photoisomers. The light energy rearranges the molecules in the chemical group to produce photobilirubin and rearranges the atoms to produce lumirubin. These can be excreted in the bile without conjugation. This isomerization is thought to be the most important in terms of bilirubin elimination.
  
• Photosensitized oxidation
  is a minor pathway, by which the bilirubin molecule absorbs light energy which is then transferred to oxygen, forming a reactive oxygen molecule. Bilirubin is then oxidized, forming a water-soluble product which is excreted in the urine with no need for conjugation.
  ²
  ,
  5
  ,
  6
  

  Strength of light
  

  A blue light, of wavelength in the of range 425–475 nanometers is used. White light can be used, but it is less effective. Recommended irradiance is between 5 and 10mcW/cm
  ²
  .
  ²
  

  Light sources
  

• Overhead strip lights
  incorporated into a unit which is designed to fit closely over the incubator hood to give maximum efficiency, maintaining the effectiveness of the treatment.
  
• Fibreoptic paddles
  used underneath the baby, often used in conjunction with overhead lights.
  
• Fibreoptic blankets
  (
  ‘Biliblankets
  ^®
  ’
  ) can be used if the baby is well enough to be held. The light source, a tungsten halogen lamp, is linked
  

  to a woven fibreoptic pad via a fibreoptic cable.
  

• Bilibed,
  a bed with lights incorporated into the base. The baby lies on
  

  the bed and is covered with a sleeping bag attached to the base.
  ⁷
  

  Recording the levels
  

• The bilirubin levels are plotted on a chart to indicate when treatment is needed.
  
• The charts differ for gestational age and for the degree of illness.
  
• The more premature, ill baby will be treated at lower levels than a term, well infant, who may not need any treatment.
  
• Incorporated into the charts are also levels at which an exchange transfusion may be required if phototherapy is not enough to control the rising levels of bilirubin.
  ⁶
  

  In practice
  

• Commence phototherapy as soon as bilirubin levels start to rise, using the charts as a guide.
  
• Give the parents a full explanation of the cause and treatment.
  
• Turn the incubator temperature down to accommodate extra heat from the lights and record the infant’s temperature frequently.
  
• The baby should be naked, but cover the gonads.
  
• Turn the baby regularly to get maximum exposure.
  
• Protect the baby’s eyes with goggles.
  
• Change nappies frequently, because of diarrhoea.
  

  NEONATAL JAUNDICE
  

  609