Extrauterine neuromaturation of low risk preterm infants

The objective of the study was to follow neuromaturation in preterm infants. From serial exams in 90 low risk very low birthweight infants, each infant's Maturity Scores (the sum of tone, reflex, and response items) were plotted against postmenstrual age (PMA) when examined. Each infant's estimated line of best fit provides two descriptors of that infant's neuromaturation: slope (Individual Maturity Slope) and y-value (Predicted Maturity Score at 32-wk PMA). We found that Maturity Scores increased with PMA; 96% had correlation coefficients >0.8. Mean Actual and Predicted Maturity Scores at 32-wk PMA were 60 and 58, respectively, in 65 infants. When stratified by gestational age, Mean Actual Maturity Score at 30-wk PMA were 50 whether infants were 1 or several weeks old when examined. Therefore, low risk preterm infants demonstrated individual variability in rate of neuromaturation. Tone, reflexes, and responses nonetheless emerged in a predictable pattern, whether neuromaturation was intrauterine or extrauterine. This unique tool that measures preterm neuromaturation requires expertise but no technology. It has an exciting potential for providing insight into how emerging central nervous system function and structure influence each other, as well as how the central nervous system recovers from injury.