Prematurity and autism: a dose-response relationship across gestational age

Area of Science:

• Perinatal health
• Neurodevelopmental disorders
• Epidemiology

Background:

• Autism spectrum disorder (ASD) is a complex neurodevelopmental condition.
• Gestational age at birth is a known factor influencing infant health outcomes.
• Understanding the precise relationship between prematurity and ASD risk is crucial for early intervention.

Purpose of the Study:

• To investigate the association between gestational age at birth and the risk of developing autism spectrum disorder (ASD).
• To quantify the dose-response relationship between decreasing gestational age and ASD incidence.

Main Methods:

• A retrospective cohort study utilized ICD-10 codes to identify ASD cases (n=1861) born between 2011-2023.
• Exact and propensity-score matching were employed to select ten controls per case, balancing key demographic and socioeconomic factors.
• Gestational age was categorized, and conditional logistic regression analyzed associations with ASD risk.

Main Results:

• A progressive increase in ASD risk was observed with greater prematurity.
• Compared to term births (37-42 weeks), adjusted odds ratios for ASD increased with earlier gestational ages.
• Significantly elevated risks were noted for infants born at 36 weeks (1.37), 34-35 weeks (1.67), 32-33 weeks (2.14), 28-31 weeks (2.95), and below 28 weeks (4.37).

Conclusions:

• Earlier gestational age is significantly associated with an increased risk of autism spectrum disorder.
• The findings demonstrate a clear dose-response relationship, where greater prematurity corresponds to higher ASD risk.
• These results underscore the importance of monitoring and support for infants born preterm regarding neurodevelopmental outcomes.