Blood Disorders in the Newborn

Question 1

What is the most common cause of polycythemia in the newborn?

Answer 1

Delayed cord clamping

Question 2

What is the most common lab abnormality found in neonates with polycythemia?

Answer 2

Hypoglycemia - found in up to 40% of infants

Question 3

Describe the cause of erythroblastosis fetalis.

Answer 3

Hemolytic disease of the fetus and newborn (HDFN) - maternal antibodies active against the RBC antigens of the infant are passed transplacentally and cause RBS destruction

Usually due to D antigen (90% of reactions) of the Rh group or ABO incompatibility; this is prevented if during the pregnancy the mother is given anti-D globulin during her 3rd trimester (28W) and again within 72 hours of delivery.

Question 4

True or False? The newborn with HDFN fetalis is likely to be jaundiced at birth. Why or why not?

Answer 4

False, because unconjugated bilirubin from the fetus crosses the placenta then is conjugated by the mother and eliminated

But jaundice can quickly develop after birth.