Newborn Jaundice

Physiologic jaundice
Jaundice caused by accelerated destruction of fetal RBCs, impaired conjugation of bilirubin, and increased bilirubin reabsorption from the intestinal tract

Basis of physiologic jaundice
Normal physiological response to being born

Factors that may give rise to physiological jaundice
Increased bilirubin in liver
Defective uptake of bilirubin from plasma
Defective conjugation of bilirubin
Defect in bilirubin excretion
Inadequate hepatic circulation
Increased reabsorption of bilirubin from intestine

The factor that differentiates pathological jaundice from physiological jaundice
Time. Pathologic jaundice appears at birth or within 24 hours of life whereas physiologic jaundice will appear after the first 24 hours

Bilirubin serum levels at which yellow will start to appear in the skin and sclera
4 to 6 milligrams per deciliter

Yellow coloring

Newborn procedures that will decrease probability of high bilirubin levels
Maintain skin temp at greater than or equal to 36.5 degrees Celsius (97.8 degrees Fahrenheit);
Monitor amount and characteristics of stool;
Encourage early feeding

Reason maintaining a normal skin temperature discourages high bilirubin levels
Cold stress causes acidosis which decreases available serum albumin-binding sites, weakens albumin-binding powers, and causes elevated unconjugated bilirubin levels

Reason it is important to monitor stool to discourage high bilirubin levels
Bilirubin is eliminated in feces. Therefore, inadequate stooling may cause reabsorption and recycling of bilirubin.

Relationship between early breastfeeding and decreasing high bilirubin levels
Colostrum has a laxative effective and increases excretion of meconium and transitional stool

Breastfeeding jaundice
Jaundice that occurs in the first days of life of breastfed newborns due to inadequate fluid intake and dehydration

Ways to prevent breastfeeding jaundice
Encouraging frequent breastfeeding (every 2 to 3 hours), avoiding supplementation, and accessing maternal lactation counseling

Breast milk jaundice
Jaundice related to milk composition promoting increased bilirubin reabsorption from the intestine. Some breast milk may contain several times the normal concentration of certain fatty acids which compete with bilirubin for binding sites on albumin and inhibit conjugation, disrupting the RBC membrane

Period in which breast milk jaundice may occur
After first week of life and may last several weeks to several months

Peak bilirubin levels for breast milk jaundice
5 to 10 milligrams per deciliter

Yellowing coloration of the skin and sclera of the eyes that develops from the deposit of yellow pigment bilirubin in lipid-fat-containing tissues

Normal total bilirubin at birth
Less than 3 milligrams per liter

Factors for pathologic jaundice diagnosis
Exhibit jaundice first 24 hours of life;
Total serum bilirubin concentration increase greater than 0.2 milligrams per deciliter per hour;
Surpass the 95th percentile on the nomogram for age in hours;
Have persistent visible jaundice after 1 week of age for term infants or after 2 weeks for preterm infants

Typical bilirubin levels between the third and fifth days of life
5 to 6 milligrams per deciliter

Reasons for physiological jaundice
Increased RBC mass
Shorter RBC lifespan
Slower uptake of bilirubin by liver
Lack of intestinal bacteria
Poorly established hydration from initial breast feeding

Lifespan of RBCs in newborns
90 days

Primary cause of pathologic hyperbilirubin
Hemolytic disease of the newborn

Erythroblastosis fetalis (alloimmune hemolytic disease)
Maternal antibodies from an Rh negative mother crosses the placenta to an Rh positive fetus, attaching and destroying the fetal RBCs. The fetal system responds by increasing more RBCs

Signs and symptoms of erythroblasosis fetalis
Jaundice, anemia, compensatory erythropoiesis, and increase in erythroblasts

Hydrops fetalis
Most severe form of erythroblastosis fetalis in which the maternal anti Rh antibodies attach to the Rh site of the fetal RBC making them susceptible to destruction

Essential lab tests for jaundice
Coombs’ test
Serum bilirublin levels (direct and total)
Reticulocyte percentage
Positive smear for cellular morphology

Coombs’ test
Tests mother’s blood to determine Rh and ABO compatability

Indirect Coomb’s test
Tests infant’s blood for antibody-coated (sensitized) Rh-positive RBCs

Transcutaneous bilirubin (TcB)
Noninvasive method of assessing bilirubin levles

Period of time in which phototherapy is most effective
24 to 48 hours of use