Anemia of Prematurity - Portal Neonatal

Causes:
• Increased fetal erythropoiesis secondary to fetal hypoxia
o Placental insufficiency can be secondary to preeclampsia, eclampsia, primary
renovascular disease, chronic or recurrent abruptio placenta, cyanotic congenital heart
disease, postdate pregnancy, maternal smoking, or intrauterine growth restriction
(IUGR).
o Endocrine abnormalities secondary to increased oxygen consumption resulting in fetal
hypoxia may be due to congenital thyrotoxicosis, congenital adrenal hyperplasia,
Beckwith-Wiedemann syndrome, or being the infant of a diabetic mother (IDM).
o Genetics disorders (eg, trisomy 13, trisomy 18, trisomy 21) also may cause in utero
hypoxia.
• Hypertransfusion
o Delayed cord clamping allows for an increased blood volume to be delivered to the
infant. When cord clamping is delayed more than 3 minutes after birth, blood volume
increases 30%.
o Gravity also may be a factor because of the position of the delivered infant in relation to
the maternal introitus before cord clamping.
o In the event of delayed cord clamping, blood flow to the infant is enhanced by oxytocin.
o Twin-to-twin transfusion syndrome due to a vascular communication occurs in
approximately 10% of monozygotic twin pregnancies.
o Maternal-fetal transfusion may occur.
o As a result of intrapartum asphyxia, the direction of blood flow in the umbilical cord tends
to be toward the fetus.
• Dehydration may be due to decreased plasma volume in relation to RBC mass.
DIFFERENTIALS Section 4 of 9
Dehydration
Polycythemia
Polycythemia Vera
Other Problems to be Considered:
Method of blood draw: Capillary Hct measurements depend on regional blood flow and can vary
widely from central venous measurements.
Iatrogenic problems: These may be related to transfusion.
Lab Studies:
WORKUP Section 5 of 9
• Along with symptoms attributable to neonatal hyperviscosity, the central venous Hct
measurement is used as a surrogate for diagnosing hyperviscosity because it is a readily
available.
• Other laboratory tests include measurements of the following:
o Serum glucose and calcium levels: Measure these to determine if the patient has
decreased levels that require treatment.
o Bilirubin level: Measure this level in the infant with jaundice and polycythemia because
the increased RBC mass leads to an increased load of bilirubin precursors that can
result in hyperbilirubinemia.
o Serum sodium level, blood urea nitrogen level, and specific gravity of urine: Measure
these values to aid in the diagnosis of dehydration.