To examine developmental outcomes at six months in a Bulgarian infant cohort using the ASQ-3 and compare these outcomes with established U.S. norms.
Approach:
Study Design: Cross-sectional study involving 155 infants assessed using the ASQ-3 during routine pediatric visits.
Statistical Analysis: One-sample t-tests were used to compare domain scores with U.S. normative means, calculating effect sizes and confidence intervals.
Secondary Analyses: Evaluated effects of birth weight, gestational age, and sex on developmental outcomes.
Key Findings:
Statistically significant differences in Gross Motor (d = −0.28) and Problem Solving (d = 0.30) were observed, with all effect sizes categorized as small (|d| ≤ 0.30).
Infants with birth weight <2,500 g showed moderate-to-large effects across multiple domains (d = −0.63 to −0.88).
No clinically meaningful differences related to gestational age were found after correction for age.
A small female advantage was noted in Communication (d = 0.37).
Interpretation:
The ASQ-3 outcomes indicate variability in developmental outcomes among Bulgarian infants, with biological risk factors appearing to have a significant impact.
Limitations:
The study's cross-sectional design limits causal inferences.
The sample size may not fully represent the broader Bulgarian population.
Conclusion:
Findings support the use of ASQ-3 in Bulgaria and emphasize the importance of considering perinatal risk factors in early developmental surveillance.
