Table 1 Search terms used to search Ovid MEDLINE, Ovid PsychINFO, Ovid Embase, Ovid Embase Classic and PubMed from the beginning of creation to late January 2020

#1 Autism

“autis*”, “autism*”, “autistic*”, “ASD”, “autism spectrum disorder*”, “PDD-NOS”, “PDDNOS”, “ unspecified PDD”, “pervasive developmental disorder*”, “pervasive developmental disorder not otherwise specified”, “Asperger*”, and “Asperger* syndrome”. The premature search terms included premature*”, “preterm”, “prematur*”, “low birth weight”.

#2 Preterm

“premature*”, “preterm”, “prematur*”, “low birth weight”.