Neurobehavioral Assessment of Newborns Using the Modified Brazelton Neonatal Behavioral Assessment Scale: Relationship with Gestational Age and Birth Weight

Abstract

Background: The neonatal period represents a crucial stage of brain maturation during which newborns adapt rapidly to life outside the uterus. Assessment of neonatal neurobehavior provides valuable information regarding neurological integrity, behavioural organization, and developmental maturity. The Modified Brazelton Neonatal Behavioral Assessment Scale (MNBAS) is a standardized instrument that evaluates multiple domains of neonatal behaviour, including habituation, orientation, motor performance, behavioural state regulation, autonomic stability, and primitive reflexes. Since gestational age and birth weight are important determinants of neurological maturity, understanding their influence on neonatal neurobehavior may facilitate early identification of infants at risk for developmental impairment.

Objectives:

Primary Objectives

• To assess the neurobehavioral profile of newborns using the Modified Brazelton Neonatal Behavioral Assessment Scale.
• To evaluate the relationship between neurobehavioral performance and gestational age.
• To determine the association between birth weight and neurobehavioral assessment scores.

Secondary Objectives

• To compare neurobehavioral performance according to gender.
• To evaluate the influence of mode of delivery on neonatal neurobehavior.

Materials and Methods: A prospective hospital-based observational study was conducted over a one-year period in the Department of Paediatrics, Sree Mookambika Institute of Medical Sciences, Kulasekaram. Eighty eligible newborns were enrolled after obtaining informed parental consent. Neurobehavioral assessment was carried out within the first 72 hours after birth using the Modified Brazelton Neonatal Behavioral Assessment Scale under standardized environmental conditions. Maternal and neonatal clinical details, including gestational age, birth weight, gender, mode of delivery, Apgar score, and anthropometric measurements, were recorded. Data were analysed using appropriate descriptive and inferential statistical methods. A p-value less than 0.05 was considered statistically significant.

Results: Among the eighty newborns studied, term infants demonstrated significantly higher neurobehavioral scores than preterm infants. Newborns with normal birth weight performed better across most behavioural domains than low birth weight infants. Gestational age showed a significant positive correlation with the overall MNBAS score, while birth weight demonstrated a moderate positive correlation with neurobehavioral performance. No significant differences were observed with respect to gender or mode of delivery.

Conclusion: The Modified Brazelton Neonatal Behavioral Assessment Scale is a practical and reliable tool for evaluating neonatal neurobehavior in routine clinical practice. Increasing gestational age and birth weight are associated with improved neurobehavioral performance, emphasizing the importance of early behavioural assessment in identifying newborns who may benefit from developmental surveillance and early intervention.