Changes in neurotrophin levels in umbilical cord blood from infants with different gestational ages and clinical conditions.

Apoptotic neuronal loss may be responsible for altered brain development associated with prematurity and perinatal insults. Neurotrophins play crucial roles in protecting neurons from entering or progressing along an apoptotic pathway. The present study examined levels of neurotrophins in human umbilical cord blood from infants at different gestational ages and clinical conditions. We collected 60 samples of cord blood and categorized them accordingly into three gestational age groups: group A (24-28 wk), group B (29-35 wk), and group C (>/=36 wk). Neurotrophin levels were determined by using brain-derived neurotrophic factor (BDNF) and neurotrophin 3 (NT3) ELISA. Clinical data were obtained by medical chart analysis. The BDNF levels were 884 +/- 386, 1421 +/- 616, and 2190 +/- 356 pg/mL in group A, group B, and group C, respectively. Significant differences were found between groups A and B (p = 0.038), groups A and C (p = 0.0001), and groups B and C (p = 0.001). Infants with severe intraventricular hemorrhage had significantly lower cord blood BDNF levels (925 +/- 513 pg/mL) compared with their normal counterparts (1650 +/- 674 pg/mL; p = 0.021). NT3 levels did not show significant change either across gestational ages or with the presence of intraventricular hemorrhage. Cord blood levels of BDNF may reflect the degree of neural maturity in premature infants. Interestingly, when a complete course of antenatal steroids was given, BDNF and NT3 cord blood levels were higher than when no steroid was given. Increased neurotrophins levels may also mediate improved neurodevelopmental outcome in infants who received antenatal steroids.