From the Guidelines
Elevated Hematocrit (Hct) in newborns is primarily caused by polycythemia, which can occur due to various factors such as delayed cord clamping, twin-to-twin transfusion syndrome, and twin anemia-polycythemia sequence (TAPS) 1.
Causes of Elevated Hematocrit
- Delayed cord clamping: This procedure can increase total body iron content at birth by approximately 33% (~75 mg) if clamping of the umbilical cord has been delayed for 2 min, leading to higher Hb and hematocrit (Ht) levels immediately after birth 1.
- Twin-to-twin transfusion syndrome: This condition can cause polycythemia in the recipient twin due to the unequal exchange of blood between the twins.
- Twin anemia-polycythemia sequence (TAPS): TAPS is a condition that occurs when there is a significant difference in the blood count between the donor and recipient twins, resulting in anemia in the donor twin and polycythemia in the recipient twin 1.
- Maternal iron status: Maternal iron status can influence neonatal iron stores at birth, with lower iron stores in newborns born to iron-deficient mothers 1.
- Gestational age: Preterm infants are at a higher risk of polycythemia due to their lower iron endowment at birth 1.
- Birth weight: Low birth weight infants are also at a higher risk of polycythemia due to their lower iron endowment at birth 1.
Diagnosis and Management
The diagnosis of elevated Hematocrit in newborns can be made through blood tests and ultrasound findings, such as discordant placental echogenicity and recipient twin cardiomegaly 1. Management of polycythemia in newborns may involve partial exchange transfusion to reduce the risk of complications such as hyperviscosity syndrome.
From the Research
Causes of Elevated Hematocrit (Hct) in Newborns
- Intra-uterine hypoxia is a factor related to the etiology of polycythemia, as stated in the study 2.
- Fetal transfusion is another factor related to the etiology of polycythemia, as mentioned in the study 2.
- Neonates born small for gestational age (SGA), infants of diabetic mothers (IDM), and multiple births are at risk for polycythemia, according to the study 3.
- The study 4 found that the most common risk factors for polycythemia were being small for gestational age, and the most common symptoms were jaundice and hypoglycemia.
- The study 5 suggests that neonates with umbilical venous hematocrit (UV Hct) greater than or equal to 63% are strongly indicative of hyperviscosity.
Risk Factors for Polycythemia
- Small for gestational age (SGA) 3, 4
- Infants of diabetic mothers (IDM) 3
- Multiple births 3
- Intra-uterine hypoxia 2
- Fetal transfusion 2