High-Risk Newborn: Acquired and Congenital Conditions

Congenital and acquired conditions are high-risk complications requiring prompt recognition and intervention. Congenital conditions refer to genetic disorders or physical anomalies that occur during fetal development, such as phenylketonuria, cleft palate, and cardiac defects.  

On the other hand, acquired conditions occur postnatally, meaning at or shortly after birth, and include pathologic jaundice, sepsis neonatorum, and meconium aspiration syndrome.

Okay, so jaundice, also known as hyperbilirubinemia, is a condition caused by the build-up of a yellow pigment called bilirubin, that’s produced in the liver by breaking down hemoglobin from red blood cells. Most newborns develop mild hyperbilirubinemia, called physiologic jaundice, which is a self-limiting condition that requires no treatment.

On the other hand, pathologic jaundice, sometimes called non-physiologic jaundice, is a more severe form of jaundice, that is most commonly caused by excessive hemolysis, or red blood cell destruction, leading to an excessive build-up of bilirubin in the blood.  

Risk factors for excessive hemolysis include incompatibility between the maternal and fetal ABO and Rh blood types; polycythemia, or an excessive amount of circulating red blood cells; or the presence of extravascular blood, like bruising or cephalohematoma from birth trauma. Other risk factors include sepsis and liver impairment.

Without proper treatment, pathologic jaundice can lead to acute bilirubin encephalopathy, where bilirubin crosses the blood-brain barrier, deposits in the brain, and causes impaired neurologic function. This can progress to kernicterus, or chronic bilirubin encephalopathy, which is irreversible neurological damage, resulting in long-term effects like cerebral palsy and hearing loss. 

Clinical manifestations of pathologic jaundice include a rapid rise in bilirubin within the first 24 hours of life that persists at an elevated level longer than expected. The newborn may have yellow-tinged sclera and mucous membranes; and in newborns with lighter skin, yellow or orange-tinged skin is often present.  

In newborns with darker skin, jaundice is often better visualized in the palms of the hands and soles of the feet.

Now, diagnosis of hyperbilirubinemia involves laboratory tests like total serum bilirubin, or TSB. The TSB can also be estimated by measuring the newborn’s transcutaneous bilirubin level, or TcB. The expected level varies with age in hours, so treatment decisions are made by plotting the level on an hour-specific graph, such as the BiliTool.  

Treatment includes phototherapy, where the newborn is placed under phototherapy lights or wrapped in a fiberoptic phototherapy blanket. The bilirubin in the skin then absorbs the light and becomes water soluble so it can be excreted through urine and stool.  

In severe cases, blood exchange transfusions are needed to reduce excess bilirubin.

Moving on to sepsis neonatorum, this is a systemic bacterial, viral, or fungal infection that develops from an infection acquired before, during, or after birth. Since the newborn’s immune system is underdeveloped, they are highly susceptible to infections.