Investigating the Relationship between Low Birth Weight in Children and Levels of Autism Spectrum Disorders Based on the Registration System in Hamadan Province, Iran

Background and Objectives: Low birth weight (LBW) is associated with an increased risk of autism spectrum disorders (ASD). However, limited research is conducted on the relationship between LBW and the severity levels of ASD. Therefore, the present study aimed to evaluate the association between LBW and the severity of ASD in Hamadan Province, Iran. Materials and Methods: The current study was conducted on 198 participants whose data were extracted from ASD research registry in Hamadan, Iran. Statistical analyses were performed using SPSS software (version 26). Results: The majority of the participants were boys (73.7%) and aged between two and five years (51.5%). Of these, 72 (36.4%) children had mild ASD, 60 (30.3%) children had moderate ASD, and 66 (33.3%) children had severe ASD. Adjusted ordinal logistic regression analysis indicated that the odds of severe ASD in children with LBW were 2.33 times higher compared to children with a birth weight above 2,500 g (P=0.018). Additionally, for every one-year increase in maternal age, the odds of severe ASD decreased significantly by 6% (OR=0.94, P=0.012). Conclusion: This study demonstrated that for each one-year increase in maternal age at the time of birth, the odds of severe ASD compared to mild and moderate ASD decreased significantly by 6% (OR=0.94, P=0.012). Furthermore, the odds of severe ASD compared to mild and moderate ASD were 2.33 times higher in children with LBW compared to those with a birth weight over 2,500 g.