Neonatal Hemoglobin Levels in Preterm Infants Are Associated with Early Neurological Functioning

Neonatal anemia may hinder oxygen transport to the brain. The effect of anemia and cerebral oxygenation on neurological functioning in the early neonatal period remains unclear. 

A recent study determined the association between initial hemoglobin levels (Hob) and early neurological functioning in preterm infants by assessing their general movements (GMs). 

Data on preterm infants born before 32 weeks of gestation was collected. Infants with intraventricular hemorrhage > grade II were excluded from the study. On day 8, infants’ GMs were assessed; both generally as normal/abnormal and in detail using the general movement optimality score (GMOS). Cerebral tissue oxygen saturation (rcSO2) on day 1 was measured using near-infrared spectroscopy. 

The results were as follows-

• 65 infants with a median gestational age of 29.9 weeks; a median birth weight of 1,180 g were included in the study. 
• Median Hob on day 1 was found to be 10.3 mmol/L. 
• Lower Hob on day 1 was found to be associated with a higher risk of abnormal GMs and poorer GMOSs. 
• Hemoglobin was found to be strongly correlated with rcSO2. 
• Infants with lower rcSO2 values were demonstrated to have a higher risk of abnormal GMs. 
• After adjusting for confounders, Hob on day 1 presented 44% of the variance of normal/abnormal GMs and rcSO2 presented 17%. 
• Concerning the explained variance of the GMOS, this was 25% and 16%, respectively. 

Thus in preterm infants, low Hob on day 1 is associated with impaired neurological functioning on day 8, which is probably due to low cerebral oxygenation.

SOURCE- Neonatology 2021;118:593-599. doi: 10.1159/000518655