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NEONATAL JAUNDICE

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BACKGROUND

Jaundice is the most common condition that requires medical attention in newborns. The yellow coloration of the skin and sclera in newborns with jaundice is the result of accumulation of unconjugated bilirubin. In most infants, unconjugated hyperbilirubinemia reflects a normal transitional phenomenon. However, in some infants, serum bilirubin levels may rise excessively, which can be cause for concern because unconjugated bilirubin is neurotoxic and can cause death in newborns and lifelong neurologic sequelae in infants who survive (kernicterus). For these reasons, the presence of neonatal jaundice frequently results in diagnostic evaluation.

Neonatal jaundice may have first been described in a Chinese textbook 1000 years ago. Medical theses, essays, and textbooks from the 18th and 19th centuries contain discussions about the causes and treatment of neonatal jaundice. Several of these texts also describe a lethal course in infants who probably had Rh isoimmunization. In 1875, Orth first described yellow staining of the brain, in a pattern later referred to by Schmorl as kernicterus.

causes

CAUSES

It is normal for a baby’s bilirubin level to be a bit high after birth.

When the baby is growing in the mother’s womb, the placenta removes bilirubin from the baby’s body. The placenta is the organ that grows during pregnancy to feed the baby. After birth, the baby’s liver starts doing this job. It may take some time for the baby’s liver to be able to do this efficiently.

Most newborns have some yellowing of the skin, or jaundice. This is called physiological jaundice. It is often most noticeable when the baby is 2 to 4 days old. Most of the time it does not cause problems and goes away within 2 weeks.

Two types of jaundice may occur in newborns who are breastfed. Both types are usually harmless.

  • Breastfeeding jaundice is seen in breastfed babies during the first week of life. It is more likely to occur when babies do not nurse well or the mother’s milk is slow to come in.
  • Breast milk jaundice may appear in some healthy, breastfed babies after day 7 of life. It is likely to peak during weeks 2 and 3 but may last at low levels for a month or more. The problem may be due to how substances in the breast milk affect the breakdown of bilirubin in the liver. Breast milk jaundice is different than breastfeeding jaundice.

Severe newborn jaundice may occur if the baby has a condition that increases the number of red blood cells that need to be replaced in the body, such as:

  • Abnormal blood cell shapes (such as sickle cell anemia)
  • Blood type mismatch between the mother and baby (Rh incompatibility)
  • Bleeding underneath the scalp (cephalohematoma) caused by a difficult delivery
  • Higher levels of red blood cells, which is more common in small-for-gestational age (SGA) babies and some twins
  • Infection
  • Lack of certain important proteins, called enzymes

Things that make it harder for the baby’s body to remove bilirubin may also lead to more severe jaundice, including:

  • Certain Medicines
  • Infections present at birth, such as rubella, syphilis, and others
  • Diseases that affect the liver or biliary tract, such as cystic fibrosis or hepatitis
  • Low oxygen level (hypoxia)
  • Infections (sepsis)
  • Many different genetic or inherited disorders

Babies who are born too early (premature) are more likely to develop jaundice than full-term babies.

neonatal-jaundice

POSSIBLE COMPLICATIONS

Rare, but serious complications from high bilirubin levels include:

  • Cerebral palsy
  • Deafness
  • Kernicterus, which is brain damage from very high bilirubin levels
  • When to Contact a Medical Professional

All babies should be seen by a provider in the first 5 days of life to check for jaundice:

  • Infants who spend less than 24 hours in a hospital should be seen by age 72 hours.
  • Infants who are sent home between 24 and 48 hours should be seen again by age 96 hours.
  • Infants who are sent home between 48 and 72 hours should be seen again by age 120 hours.

Jaundice is an emergency if the baby has a fever, has become listless, or is not feeding well. Jaundice may be dangerous in high-risk newborns.

Jaundice is generally NOT dangerous in babies who were born full term and who do not have other medical problems. Call the infant’s provider if:

  • Jaundice is severe (the skin is bright yellow)
  • Jaundice continues to increase after the newborn visit, lasts longer than 2 weeks, or other symptoms develop
  • The feet, especially the soles, are yellow

newborn-with-jaundice

RISK FACTORS

The risk of developing significant neonatal jaundice is increased in:

  • Low birth weight: premature and small for dates.
  • Breast-fed babies.
  • A previous sibling with neonatal jaundice requiring phototherapy.
  • Visible jaundice in the first 24 hours.
  • Infants of mothers who have diabetes.
  • Male infants.
  • East Asians.
  • Populations living at high altitudes.

 

PROLONGED JAUNDICE

In babies with a gestational age of 37 weeks or more with jaundice lasting for more than 14 days, and in babies with a gestational age of less than 37 weeks with jaundice lasting for more than 21 days:

  • Look for pale chalky stools and/or dark urine that stains the nappy.
  • Measure the conjugated bilirubin.
  • Carry out an FBC.
  • Carry out a blood group determination (mother and baby) and direct antiglobulin test (DAT, or Coombs’ test). Interpret the result taking account of the strength of reaction, and whether the mother received prophylactic anti-D immunoglobulin during pregnancy.
  • Carry out a urine culture.
  • Ensure that routine metabolic screening (including screening for congenital hypothyroidism) has been performed.
  • Follow expert advice about care for babies with a conjugated bilirubin level greater than 25 µmol/L because this may indicate serious liver disease.

 

WHEN TO SEEK MEDICAL CARE FOR NEWBORN JAUNDICE

Call your doctor if your newborn baby becomes jaundiced.

  • If your doctor is aware of the jaundice and you are observing your child at home, call your doctor if the jaundice spreads to the arms or legs or if it lasts beyond 1 week.
  • Call your doctor if you don’t feel comfortable watching your child at home or if you have any other questions or concerns.

 

Young mum and baby.

BREAST MILK JAUNDICE

Whereas breast feeding jaundice is a mechanical problem, breast milk jaundice is a biochemical occurrence and the higher bilirubin possibly acts as an antioxidant. Breast milk jaundice occurs later in the newborn period, with the bilirubin level usually peaking in the sixth to 14th days of life. This late-onset jaundice may develop in up to one third of healthy breastfed infants.

First, at birth, the gut is sterile, and normal gut flora takes time to establish. The bacteria in the adult gut convert conjugated bilirubin to stercobilinogen which is then oxidized to stercobilin and excreted in the stool. In the absence of sufficient bacteria, the bilirubin is de-conjugated by brush border β-glucuronidase and reabsorbed. This process of re-absorption is called enterohepatic circulation. It has been suggested that bilirubin uptake in the gut (enterohepatic circulation) is increased in breast fed babies, possibly as the result of increased levels of epidermal growth factor (EGF) in breast milk. Breast milk also contains glucoronidase which will increase deconjugation and enterohepatic recirculation of bilirubin.

Second, the breast-milk of some women contains a metabolite of progesterone called 3-alpha-20-beta pregnanediol. This substance inhibits the action of the enzyme uridine diphosphoglucuronic acid (UDPGA) glucuronyl transferase responsible for conjugation and subsequent excretion of bilirubin. In the newborn liver, activity of glucuronyl transferase is only at 0.1-1% of adult levels, so conjugation of bilirubin is already reduced. Further inhibition of bilirubin conjugation leads to increased levels of bilirubin in the blood. However, these results have not been supported by subsequent studies.

Third, an enzyme in breast milk called lipoprotein lipase produces increased concentration of nonesterified free fatty acids that inhibit hepatic glucuronyl transferase, which again leads to decreased conjugation and subsequent excretion of bilirubin.

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DIAGNOSIS

Clinical Assessment

This method is less accurate and more subjective in estimating jaundice.

Ingram icterometer:

In this method a piece of transparent plastic known as Ingram icterometer is used. Ingram icterometer is painted in five transverse strips of graded yellow lines. The instrument is pressed against the nose and the yellow colour of the blanched skin is matched with the graded yellow lines and bilirubin level is assigned.

Transcutaneous bilirubinometer:

This is hand held, portable and rechargeable but expensive and sophisticated. When pressure is applied to the photoprobe, a xenon tube generates a strobe light, and this light passes through the subcutaneous tissue. The reflected light returns through the second fiber optic bundle to the spectrophotometric module. The intensity of the yellow color in this light, after correcting for the hemoglobin, is measured and instantly displayed in arbitrary units.

Any of the following features characterizes pathological jaundice:

  1. Clinical jaundice appearing in the first 24 hours or greater than 14 days of life.
  2. Increases in the level of total bilirubin by more than 8.5 μmol/l (0.5 mg/dL) per hour or (85 μmol/l) 5 mg/dL per 24 hours.
  3. Total bilirubin more than 331.5 μmol/l (19.5 mg/dL) (hyperbilirubinemia).
  4. Direct bilirubin more than 34 μmol/l (2.0 mg/dL).

The aim of clinical assessment is to distinguish physiological from pathological jaundice. The signs which help to differentiate pathological jaundice of neonates from physiological jaundice of neonates are the presence of intrauterine growth restriction, stigma of intrauterine infections (e.g. cataracts, small head, and enlargement of the liver and spleen), cephalohematoma, bruising, signs of bleeding in the brain’s ventricles. History of illness is noteworthy. Family history of jaundice and anemia, family history of neonatal or early infant death due to liver disease, maternal illness suggestive of viral infection (fever, rash or lymphadenopathy), maternal drugs (e.g. sulphonamides, anti-malarials causing red blood cell destruction in G6PD deficiency) are suggestive of pathological jaundice in neonates.

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PHOTOTHERAPY

Phototherapy is treatment with light. It is used in some cases of newborn jaundice to lower the bilirubin levels in your baby’s blood through a process called photo-oxidation.

Photo-oxidation adds oxygen to the bilirubin so it dissolves easily in water. This makes it easier for your baby’s liver to break down and remove the bilirubin from their blood.

There are two main types of phototherapy:

  • conventional phototherapy – where your baby is laid under a halogen or fluorescent lamp with their eyes covered
  • fibreoptic phototherapy – where your baby lies on a blanket that incorporates fibreoptic cables; light travels through the fibreoptic cables and shines on to your baby’s back

In both methods of phototherapy, the aim is to expose your baby’s skin to as much light as possible.

Conventional phototherapy is the treatment tried first in most cases, although fibreoptic phototherapy may be used first if your baby was born prematurely.

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These types of phototherapy will usually be stopped for 30 minutes every three to four hours so you can feed your baby, change their nappy, and give them a hug.

If your baby’s jaundice doesn’t improve after conventional or fibreoptic phototherapy, continuous multiple phototherapy may be offered. This involves using more than one light and often a fibreoptic blanket at the same time.

Treatment won’t be stopped during continuous multiple phototherapy. Instead, milk that has been squeezed out of your breasts in advance may be given through a tube into your baby’s stomach, or fluids may be given into one of their veins (intravenously).

During phototherapy, you baby’s temperature will be monitored to ensure they’re not getting too hot and they’ll be checked for signs of dehydration. Your baby may need intravenous fluids if they’re becoming dehydrated and aren’t able to drink a sufficient amount.

The bilirubin levels will be tested every four to six hours after phototherapy has started. Once levels start to fall, they’ll be checked every six to 12 hours.

Phototherapy will be stopped when the bilirubin level falls to a safe level, which usually takes a day or two.

Phototherapy is generally very effective for newborn jaundice and has very few side effects, although your baby may develop a temporary rash or tan as a result of the treatment.

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EXCHANGE TRANSFUSION

A blood transfusion, known as an exchange transfusion, may be recommended if your baby has particularly high levels of bilirubin in their blood or if phototherapy hasn’t been effective.

During an exchange transfusion, small amounts of your baby’s blood are removed through a thin plastic tube placed into blood vessels in their umbilical cord, arms or legs. The blood is then replaced with blood from a suitable matching donor (someone with the same blood group).

As the new blood won’t contain bilirubin, the overall level of bilirubin in your baby’s blood will fall quickly.

Your baby will be monitored throughout the transfusion process, which can take several hours to complete. Any problems that may arise, such as bleeding, will be treated.

Your baby’s blood will be tested within two hours of treatment to check if it’s been successful. If the level of bilirubin in your baby’s blood remains high, the procedure may need to be repeated.