Hello and welcome to the Zero to Finals podcast. My name is Tom and in this episode I'm going to be talking to you about

neonatal jaundice. And if you want to follow along with written notes on this topic, you can follow along at

zero definals.com slash neonatal jaundice or in the neonatology section of the zero to finals pediatrics book.

So let's get straight in.

Jaundice refers to an abnormally high level of bilirubin in the blood.

We need to have some basic understanding of the process of bilirubin production in the blood

so that we can understand where this bilirubin

comes from when we break down the causes of neonatal jaundice. Red blood cells contain

unconjugated bilirubin. When red blood cells break down, they release unconjugated bilirubin

into the blood. Unconjugated bilirubin is then conjugated in the liver, and conjugated

bilirubin is excreted in two ways, either via the biliris system into the gastrointestinal tract

or into the urine. Firstly, the main cause of neonatal jaundice is called physiological jaundice,

and we need to understand why this happens. There's a high concentration of red blood cells

in the fetus and the neonate. These red blood cells are more fragile than normal red blood

cells. The fetus and the neonate also have less well

developed liver function. Fetal red blood cells break down more rapidly than normal red blood cells

releasing lots of bilirubin. Normally this bilirubin is excreted via the placenta. However, at birth,

the fetus no longer has access to the placenta to excrete

the bilirubin. This leads to a normal rise in bilirubin shortly after birth, causing a mild

yellowing of the skin and the sclera, usually from day two to seven of age. This usually resolves

completely by 10 days and most babies will remain

otherwise healthy and well. Other than physiological jaundice, there are other causes of

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