Overview of Neonatal Jaundice

What is neonatal jaundice?

Neonatal jaundice (or jaundice) is a condition in which the concentration of bilirubin (bile pigment) in the blood increases too high, thereby penetrating the skin and connective tissues, causing yellowing of the skin and mucous membranes (sclera, tongue, etc.) in humans.

For most newborns, jaundice is a physiological phenomenon, appearing within 24 hours after birth and usually disappears after 1 week (for full-term babies) or approximately 2 weeks for premature babies (<36 weeks old). Neonatal jaundice is often due to the baby’s liver not being mature enough to remove bilirubin from the blood. Therefore, treatment of neonatal jaundice is usually not necessary.

However, if the jaundice does not subside after this time or the jaundice is more severe than normal, this is no longer a physiological phenomenon but a pathological condition, requiring medical intervention as soon as possible. If intervention is delayed, it will lead to kernicterus with early manifestations such as:

• The child sucks poorly, sleeps lethargically, has decreased muscle tone, decreased reflexes, cries out in fits, or the child may have increased muscle tone, arches the body, or has convulsions
• Most children gradually go into a coma and often die during apnea at this stage.
• The child may have neurological and mental sequelae such as slurred speech or muteness, deafness, strabismus, blindness, paralysis of one or more limbs, choreoathetoid cerebral palsy, looking up, stupidity, and low intelligence.

Therefore, it is necessary to actively treat jaundice due to increased indirect bilirubin in newborns, especially in the first 15 days after birth to avoid any brain damage, especially kernicterus.

Causes of Neonatal Jaundice

Bilirubin is one of the degradation products of red blood cells. After the red blood cell finishes its life cycle (about 120 days) or is destroyed by some cause, it is captured by the reticuloendothelial system and phagocytosed, forming 3 components: Globin, iron ion and Hem nucleus. Globin and iron will be reused by the body to synthesize new red blood cells. Only the Hem nucleus continues to be degraded and forms bilirubin. Normally, the formed bilirubin will be “captured” by the liver, accumulated in the gallbladder (bilirubin is also called facial pigment because it is the main agent that makes bile yellow) and then excreted in the stool (diagram above). However, if the amount of bilirubin formed is too much, too fast (due to hemolysis, causing massive red blood cell rupture) or due to problems, liver-biliary diseases (eg acute hepatitis, biliary obstruction) causing the liver to not be able to perform the function of eliminating bilirubin, it will cause the concentration of bilirubin in the blood to increase, leading to clinical manifestations of jaundice syndrome.

In newborns, the cause of neonatal jaundice is due to the replacement of newborn red blood cells (which have the function of nourishing the body during pregnancy) with mature red blood cells. Newborn red blood cells that are massively eliminated after birth will be massively ruptured, leading to a spike in the concentration of bilirubin in the baby and leading to clinical jaundice

During pregnancy, the mother’s liver will remove bilirubin for the fetus. After birth, it takes a while for the baby’s liver to start working. As a result, bilirubin accumulates in the baby’s blood and causes jaundice.

Babies at risk of neonatal jaundice include:

• Premature babies (born before 36 weeks of gestation or weighing < 2500g). Premature babies may not be able to process bilirubin as quickly as full-term babies.
• Babies who are not breastfed or formula-fed, either because they have difficulty feeding or because their mothers do not have enough milk. Insufficient fluid in the body causes bilirubin levels in the blood to rise. Therefore, if the mother does not have enough milk to breastfeed, the baby is more likely to develop jaundice. Formula-fed babies also develop jaundice if they do not have enough milk.
• Babies whose blood type is incompatible with their mother’s blood type (Rh or ABO incompatibility) can develop antibodies in the mother’s blood that can destroy the baby’s red blood cells and cause a sudden increase in bilirubin levels.

Other causes of jaundice in newborns include:

• Bruises at birth or other internal bleeding: Sometimes babies bruise during birth. If a newborn has bruises, he or she may have a higher level of bilirubin from the breakdown of those blood cells;
• Infections;
• G6PD deficiency;
• Newborns are more likely to have jaundice if they: have a sibling with jaundice;
• Are of East Asian descent;
• Have certain genetic disorders (Gilbert’s syndrome, congenital red blood cell membrane defects (eg, sickle cell disease, target cell anemia, hereditary galactosemia).
• Have diseases such as cystic fibrosis or hypothyroidism.

Symptoms of Neonatal Jaundice

Clinical symptoms

The degree of jaundice depends on the concentration of bilirubin in the blood, from mild cases of pale yellow or bright yellow (straw yellow) to severe cases of dark yellow like brown

The yellow color will first appear on the baby’s face, then move down to the neck and chest. In severe cases, it will continue to spread down to the toes and fingers.

Some other symptoms that may appear when the bilirubin concentration is too high are:

• The mucous membranes of the eyes are dark yellow;
• Dark urine;
• Pale or clay-colored stools.

Subclinical symptoms

• Biochemical tests show high concentrations of bilirubin in the blood and urine (> 17 µmol/l)
• Imaging diagnosis: helps confirm the diagnosis in some cases of jaundice caused by congenital diseases of the liver and biliary tract.

Who is at risk for Neonatal Jaundice

Severe jaundice, if left untreated, can cause serious complications.

Acute bilirubin encephalopathy

Bilirubin is toxic to brain cells. If a baby has severe jaundice, there is a risk that bilirubin will get into the brain, a condition called acute bilirubin encephalopathy. Treatment can prevent significant long-term damage.

The following signs may indicate acute bilirubin encephalopathy in a baby with jaundice:

• A listless, ill-tempered or difficult to wake.
• A high-pitched cry.
• Reluctant to breastfeed or feed.
• Fever.

Kernel jaundice

Kernel jaundice is a syndrome that occurs if acute bilirubin encephalopathy causes long-term toxicity to the brain. Kernicterus can lead to:

• Cerebral palsy.
• Frequently looking up.
• Hearing poorly.
• Intellectual impairment.

Preventing Neonatal Jaundice

Caring for a Jaundice Child at Home:

• The best way to prevent neonatal jaundice is to feed your baby well. Babies need to be fed 8-12 times a day for the first few days of life. Infant formula should usually have about 30-60 ml of formula every 2-3 hours for the first week.
• Re-examine your baby every day until the jaundice is gone (usually 1 week)
• Closely monitor the progression of jaundice.
• Monitor for early signs of severe jaundice such as: lethargy, refusal to feed, decreased or increased muscle tone, screaming, fever, convulsions, etc.
• Take your baby to see a pediatrician early when the baby’s jaundice becomes paler, or shows signs of severe jaundice.

Mothers need to observe their child’s skin under sunlight every day and when they detect signs of jaundice in their child: bright yellow skin, lemon yellow skin, yellow skin to the belly or yellow skin to the feet, they need to take the child to the hospital immediately for examination and timely treatment.

Note: sun exposure does not reduce jaundice in children.

Measures to diagnose neonatal jaundice

After birth, the baby will be examined by doctors to detect whether he/she has jaundice or not. Usually, after 3-5 days, when the bilirubin concentration in the blood reaches its peak, depending on the baby’s condition, the doctors can conclude whether the baby has pathological jaundice or not.

However, there are also cases where the baby leaves the hospital early (right after birth) or jaundice appears late, at which time only the family can detect whether the baby has jaundice or not. Therefore, you should take your baby to see a doctor if you detect signs such as:

• Jaundice in the abdomen, arms and legs;
• Jaundice lasting > 1 week for full-term babies or > 2 weeks for premature babies;
• The whites of the baby’s eyes turn yellow;
• The baby seems tired or has difficulty waking up;
• The baby does not gain weight or has a poor appetite;
• The baby cries a lot.

Therefore, parents need to know how to check if their baby has jaundice by the following measures:

• Bring your baby into a room with lots of natural light or under fluorescent lights
• If your baby has fair skin, gently press your finger on the forehead, nose or chest and look for yellow on the skin after releasing your finger
• If your baby has dark skin, look for yellow on the gums or whites of the eyes.

Treatments for Neonatal Jaundice

Treatment of jaundice depends entirely on the cause of jaundice.

For neonatal jaundice, it will usually go away on its own after about 2-3 weeks. If it does not go away on its own or there are signs of worsening, the following treatments should be applied

Phototherapy

This is the simplest, safest and most effective method to date. You put your baby in a crib, bare under fluorescent lights and have their eyes covered to protect their eyes during the treatment process. Ultraviolet light converts the unconjugated bilirubin that permeates the brain and skin tissues into a conjugated bilirubin that is easily transported in the blood and excreted in the urine.

Intravenous Immunoglobulin

This method is used if jaundice is caused by different blood types between the mother and baby. In this case, the baby’s blood will carry antibodies from the mother. These antibodies will contribute to the breakdown of blood cells. Immunoglobulin is a synthetic preparation that limits these antibodies, so injecting immunoglobulin into the body will help reduce the baby’s jaundice.

Exchange Blood Method

Phototherapy is usually effective, but if the jaundice becomes severe or the baby’s bilirubin level continues to increase despite active phototherapy, the baby will need to be admitted to the intensive care unit for a blood exchange. This blood exchange replaces some of the baby’s blood with high bilirubin levels with donated blood that has normal bilirubin levels.

Ensuring that your baby receives adequate nutrition (whether breastfed or formula fed) helps your baby digest better and quickly excrete bilirubin through the stool.