Perinatal and Socio-Demographic Factors Associated With Autism Spectrum Disorder in Children Aged Three to Six Years: A Hospital-Based Cross-Sectional Study

Background: Autism spectrum disorder (ASD) is a neurodevelopmental disorder that is being identified with increasing frequency worldwide. It arises from a complex interplay of genetic, environmental, perinatal, and socio-demographic influences. A better understanding of these contributing factors is important for improving early identification and guiding preventive strategies. Within this framework, the present study sought to evaluate the perinatal and socio-demographic factors linked to ASD in children aged three to six years. Methods: This cross-sectional study, conducted in a hospital setting, took place at a tertiary care center in Bhubaneswar, Odisha, India, between June 2024 and March 2025. A total of 160 children aged three to six years with suspected ASD were included using convenience sampling. Screening was performed using the Trivandrum Autism Behavioural Checklist (TABC), followed by confirmatory diagnosis with the INCLEN Diagnostic Tool for Autism Spectrum Disorder (INDT-ASD). Data on perinatal factors (gestational age, birth order, mode of delivery, and pregnancy-related complications, including maternal anemia, gestational diabetes, pregnancy-induced hypertension, hypothyroidism, premature rupture of membranes, antepartum hemorrhage, and meconium-stained amniotic fluid) and socio-demographic variables (age, sex, family type, and maternal smoking) were collected. Categorical variables were analyzed using the chi-square or Fisher's exact test, while continuous variables were compared using the independent samples t-test. Odds ratios (OR) with 95% confidence intervals (CI) were computed, and a p-value < 0.05 was taken as statistically significant. Results: Out of 160 children aged three to six years with suspected ASD, 25 (15.6%) were diagnosed with ASD. A significant male preponderance was noted (OR: 3.61; 95% CI: 1.17-11.10; p = 0.026). Maternal anemia (OR: 3.35; 95% CI: 1.39-8.05; p = 0.007) and maternal smoking (OR: 10.22; 95% CI: 3.97-26.29; p < 0.001) were significantly associated with ASD. Children from nuclear families had significantly lower odds of ASD compared to joint families (OR: 0.09; 95% CI: 0.04-0.24; p < 0.001). No other factors showed statistically significant associations. Conclusion: Male gender, maternal anemia, smoking, and family structure were identified as important associated factors. These observations highlight the need to address modifiable maternal risk factors and consider socio-cultural influences in early detection. Further large-scale prospective studies are needed to confirm these associations.