NEONATAL POLYCYTHEMIA CAUSES
Category: Child Health
Abstract : 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 cons
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.
Lab Studies: • 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. o Arterial blood gases (ABG): Consider measuring ABG values to assess oxygenation in the symptomatic infant. o Platelet count: This count may demonstrate thrombocytopenia if thrombosis or DIC are present.
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