Sex Differences in Autistic Youth Born Extremely Preterm.

This study looked at 61 children born very early (23-27 weeks) who were later diagnosed with autism. At age 10, boys showed more obvious autism traits than girls on detailed diagnostic tests, especially in social skills and repetitive behaviors. However, standard autism screening tools didn't pick up these differences at ages 2 or 10. This suggests screening tools might miss autism in very premature children, especially girls.

This longitudinal study examined sex differences in autistic traits among 61 youth (20 females) born extremely preterm (23-27 weeks) who were later diagnosed with autism spectrum disorder at age 10. Using gold-standard diagnostic measures (ADOS-2, ADI-R), researchers found that males scored significantly higher than females on Social Affect and Repetitive/Restricted Behaviors, with marginal evidence for differences in communication domains. Notably, no sex differences were detected on autism screening tools (M-CHAT at 2 years, SCQ and SRS-2 at 10 years). These findings parallel sex differences observed in full-term autistic youth and suggest that current screening tools may under-identify autism in extremely preterm youth, particularly females.

Standard autism screening tools may inadequately identify autism in extremely preterm youth, particularly females. Clinicians should consider comprehensive diagnostic assessment for extremely preterm children showing subtle autism traits, even if screening tools are negative. Sex-specific presentation patterns should inform clinical evaluation approaches.

Small sample size (N=61, only 20 females) limits statistical power and generalizability. Single cohort study design. Limited information about potential confounding factors related to prematurity complications or developmental outcomes that might influence autism presentation.

To evaluate sex differences in autistic traits in youth born extremely preterm (EP; 23-27 weeks) who were later diagnosed with autism spectrum disorder (ASD) at 10-years. A longitudinal cohort design from the Extremely Low Gestational Age Newborn Study (ELGAN) followed N = 857 EP infants from birth through 10-years. EP infants later diagnosed with ASD (N = 61, 20 females) participated in the study. Group differences were evaluated via inferential and Bayesian statistics (values > 1 suggest evidence for alternate hypothesis) on ASD screeners (M-CHAT at 2-years, SCQ and SRS-2 at 10-years), and gold-standard diagnostic measures (ADOS-2, ADI-R) at 10-years.

Males scored significantly higher than females on measures of Social Affect from the ADOS-2, t(34.27)=-2.20, BF = 2.33, and measures of Repetitive and Restricted Behaviors from the ADI-R, t(40.52)=-2.85, BF = 5.26. Bayesian estimates suggested marginal evidence for sex differences in Nonverbal Communication, t(30.66)=-1.81, BF = 1.25, and Verbal Communication, t(24.64)=-1.89, BF = 1.39, from the ADI-R, wherein males scored higher than females. No statistically significant sex differences were identified on any of the ASD screeners at 2 (M-CHAT) or 10 years (SCQ). No significant sex differences were observed on any subscales of the SRS at 10 years.

EP autistic males present with more autistic traits than EP autistic females on gold-standard diagnostic measures of autism at 10-years of age, despite not presenting with higher autistic traits on screeners at either age. These results align with sex differences observed in full-term, autistic youth. These results suggest ASD screeners may under identify autism in EP youth, particularly females.