AbstractBackground and AimsAutism spectrum disorder (ASD) is a neurodevelopmental disorder with a higher likelihood of being diagnosed in preterm populations. Likewise, low birthweight has also been connected with an increased likelihood of ASD. The objectives were to study the frequency and define the relationship between ASD, gestational age, birthweight, and growth percentiles for preterm children.MethodsA sample of preterm children with very low birthweight was selected from the Spanish population at 7–10 years old. Families were contacted from the hospital, and they were offered an appointment to conduct a neuropsychological assessment. The children who showed signs of ASD were referred to the diagnostic unit for differential diagnosis.ResultsA total of 57 children completed full assessments, with 4 confirmed ASD diagnoses. The estimated prevalence was 7.02%. There were statistically significant weak correlations between ASD and gestational age (τb = −0.23), and birthweight (τb = −0.25), suggesting there is a higher likelihood of developing ASD for those born smaller or earlier in their gestation.ConclusionThese results could improve ASD detection and outcomes for this vulnerable population while also supporting and enhancing previous findings.