Page 60 - 16Neonatal Jaundice_compressed

2 Introduction

2.1 Neonatal jaundice

Jaundice is one of the most common conditions requiring medical attention in newborn babies.
Approximately 60% of term and 80% of preterm babies develop jaundice in the first week of
life, and about 10% of breastfed babies are still jaundiced at 1 month of age. In most babies
with jaundice thevre is no underlying disease, and this early jaundice (termed ‘physiological
jaundice’) is generally harmless. However, there are pathological causes of jaundice in the
newborn, which, although rare, need to be detected. Such pathological jaundice may co-exist
with physiological jaundice.
Neonatal jaundice refers to yellow colouration of the skin and the sclera (whites of the eyes) of
newborn babies that results from accumulation of bilirubin in the skin and mucous membranes.
This is associated with a raised level of bilirubin in the circulation, a condition known as
hyperbilirubinaemia.

Bilirubin
Bilirubin is a breakdown product of the red cells in the blood. Red cell breakdown produces
unconjugated (or ‘indirect’) bilirubin, which is mostly bound to albumin. Unconjugated
bilirubin is metabolised in the liver to produce conjugated (or ‘direct’) bilirubin, which then
passes through the gut and is excreted in the stool. Bilirubin can be reabsorbed again from
stools remaining in the gut.
Newborn babies’ red blood cells have a shorter lifespan than those of adults. The concentration
of red blood cells in the circulation is also higher in newborns than it is in adults, so bilirubin
levels are higher than they are later in life. The metabolism, circulation and excretion of
bilirubin is also slower than in adults. Thus a degree of hyperbilirubinaemia occurring as a result
of this normal physiological mechanism is common in newborn babies and usually harmless. It
is difficult to tell which babies are at risk of developing high levels of bilirubin that could
become dangerous, or who have a serious problem as the explanation for their jaundice, which
is why this guideline has been developed.
Physiological jaundice

Breastfed babies are more likely than bottle-fed babies to develop physiological jaundice within
the first week of life but the appearance of jaundice is not a reason to stop breastfeeding.
Physiological jaundice refers to the common, generally harmless, jaundice seen in many
newborn babies in the first weeks of life and for which there is no underlying cause. The
reasons for the association between breastfeeding and neonatal jaundice have not yet been fully
elucidated but may include inadequate breastfeeding support leading to a reduced intake,
sluggish gut action leading to an increase in the entero-hepatic circulation of bilirubin, or
unidentified factors in breast milk. Finally, it may be that there is a relative reduction of bilirubin
levels in formula-fed babies due to increased clearance of bilirubin from the gut. Current NHS
practice of early postnatal discharge, often within 24 hours, reduces the opportunity to assess
whether successful lactation has been established and to provide adequate breastfeeding
support and advice. Existing guidelines, including ‘Routine postnatal care of women and their
babies', NICE clinical guideline 37 (2006) (www.nice.org.uk/CG37), deal with breastfeeding
and lactation/feeding support and have been referred to wherever appropriate.

Prolonged jaundice
Prolonged jaundice, that is jaundice persisting beyond the first 14 days, is also seen more
commonly in term breastfed babies. The mechanism for this ‘breast milk jaundice’ is still not

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