Neurodevelopmental Profile of 6-Month-Old Infants

Purpose: The first months of life are a critical period for brain development. This study assessed neurodevelopment in 6-month-old infants using the Ages and Stages Questionnaire, Third Edition (ASQ-3), and examined variability across developmental domains. Material/Methods: A cross-sectional observational study was conducted in Bulgaria between August and December 2025. A total of 146 term infants aged 6 months (±2 weeks) were assessed with the 6-month ASQ-3, covering communication, gross motor, fine motor, problem-solving, and personal-social development. Descriptive statistics, chi-square tests with post-hoc standardized residuals, and independent-samples t-tests were applied. Results: The highest mean scores were observed in Problem Solving (54.0 ± 8.2) and communication (51.0 ± 7.5), while Gross Motor had the lowest mean score (41.1 ± 11.9). The Gross Motor domain also had the highest proportion of infants requiring monitoring or further assessment (31.5%). Item-response distributions differed significantly within all domains (all p < 0.001), with greater variability in several more complex skills. No statistically significant sex differences were found. Conclusions: Neurodevelopment at 6 months shows substantial domain-specific variability, with basic skills generally more established than complex abilities. Standardized screening with ASQ-3 may support early identification of infants requiring monitoring or further assessment.