A quarterly publication of the Autism Research Institute

The Autism Research Review International is quarterly publication of the Autism Research Institute

Fall, 2020 | Number 4, Volume 34

Early or late birth tied to small increase in ASD risk

Children born either pre- or post-term have a slightly increased risk for autism spectrum disorders (ASD), according to a large-scale study. 

Martina Persson and colleagues analyzed data from medical registries in Sweden, Finland, and Norway. The databases included information on more than 3.5 million children born between 1995 and 2015. 

The researchers found that the risk of ASD increased slightly for each week a child was born pre- or post-term. This risk was independent of sex and birth weight for gestational age. Persson and colleagues note, “The risk of ASD was not confined to the pre- or post-term periods but was also higher during weeks of gestation commonly included in the definition of ‘term’ birth, i.e., [there was a] higher risk at individual gestational weeks immediately below and above week 40. This is in line with the shape of risk patterns reported for other neurological outcomes, including cerebral palsy and cognitive ability (IQ).”


um disorder in Sweden, Finland, and Norway: a cohort study,” Martina Persson, Signe Opdahl, Kari Risnes, Raz Gross, Eero Kajantie, Abraham Reichenberg, Mika Gissler, and Sven Sandin, PLOS Medicine, September 22, 2020 (free online). Address: Martina Persson, Department of Medical Epidemiology and Biostatistcs, Karolinska Institutet, Stockholm, Sweden, [email protected]


“Small increase in risk of autism seen for pre and post-term births,” news release, Public Library of Science, September 22, 2020.