Neonatal jaundice occurs due to an accumulation of unconjugated bilirubin in the skin and mucous membranes. In the womb, the fetus relies on the maternal placenta to clear bilirubin. After birth, the newborn's own organs must take over this heavy workload.
Red blood cells break down naturally at the end of their lifespan, releasing hemoglobin. This hemoglobin breaks down into heme and globin, and the heme is converted into biliverdin and then into unconjugated bilirubin. Because this form of bilirubin is fat-soluble, it binds to albumin in the bloodstream and travels to the liver.
Inside the liver, the enzyme glucuronyl transferase attaches sugar molecules to the bilirubin, changing it into a water-soluble form known as conjugated bilirubin. The baby then excretes this water-soluble bilirubin through urine and stool. Newborns often develop high bilirubin levels because their liver enzymes work slowly, and their gut reabsorbs extra bilirubin before it can leave the body.
Physiological jaundice is a normal, expected transition process for most newborns. It typically appears around the second or third day of life as the baby processes a high load of fetal red blood cells.
Key characteristics of physiological jaundice include:
While harmless in most term babies, midwives must still monitor these infants closely. A breastfed baby may experience a variation called breast milk jaundice, which lasts a bit longer but remains entirely benign as long as weight gain and feeding are normal.
Pathological jaundice signals an underlying disease process that demands urgent medical attention. Unlike the normal transition of physiological jaundice, pathological jaundice can lead to permanent brain damage if left untreated.
Watch out for these critical warning signs:
Differentiating between normal newborn transition and dangerous disease states guides clinical decision-making on the postnatal ward.
| Feature | Physiological Jaundice | Pathological Jaundice |
|---|---|---|
| Onset | After 24 hours of life | Within the first 24 hours |
| Duration | Fades within 1 to 2 weeks | Persists beyond 2 weeks |
| Rate of Rise | Gradual (< 5 mg/dL/day) | Rapid (> 5 mg/dL/day) |
| Clinical State | Baby feeds and acts normally | Baby may be lethargic or ill |
Midwives must review the birth history, feeding patterns, and exact timeline of appearance whenever assessing a yellow newborn. Relying on visual inspection alone can be misleading, especially across different skin tones.
Certain newborns carry a higher chance of developing dangerously high bilirubin levels. Identifying these risk factors early allows midwives to implement preventive monitoring.
Evaluating a jaundiced newborn requires a combination of careful physical examination and laboratory testing. In busy Nigerian maternity wards, midwives play a front-line role in spotting changes early.
Kramer's rule helps estimate bilirubin spread by observing skin tint from head to toe. Face and neck yellowing suggests low levels, while yellowing extending to the palms and soles indicates very high, dangerous levels that demand immediate blood work.
However, visual checks alone are unreliable, especially in darker-skinned infants where skin tones mask subtle changes. Clinicians confirm levels using serum total bilirubin (TB) blood tests or non-invasive transcutaneous bilirubinometers when available. Blood grouping, direct Coombs testing, and packed cell volume checks help uncover underlying causes like hemolysis.