Periconceptional Serum Creatinine and Risk of Childhood Autism Spectrum Disorder: A Research Letter

Background: Autism spectrum disorder (ASD) is a neurodevelopmental condition that manifests in early childhood, in which the maternal metabolic syndrome may be a risk factor. The kidney is a barometer of maternal metabolic syndrome duration and severity.Objective: The main objective of this study is to determine whether periconceptional kidney function is associated with ASD in early childhood.Design, Setting, and Participants: This retrospective population-based cohort study was completed in Ontario, Canada. Included were singleton children born in an Ontario hospital between April 2007 and March 2021, who were alive at age 48 months and whose mother had a recorded prepregnancy body mass index (BMI) and a measured serum creatinine (SCr) between 120 days preconception and 28 days postconception.Measurement: The main study outcome was a diagnosis of ASD between ages 24 and 48 months.Methods: Relative risks (RRs) of ASD in association with periconceptional SCr were generated using modified Poisson regression and adjusted for several confounders.Results: The cohort comprised 86 054 women, who had 89 677 liveborn children surviving to at least 48 months of age. There was no significant association between periconceptional SCr and ASD (RR: 0.86; 95 % confidence interval: [0.67, 1.10]).Limitations: Selection bias may have arisen had SCr been ordered on clinical grounds.Conclusions: Further study is warranted to determine whether prepregnancy glomerular hyperfiltration is a marker of ASD and other behavioral conditions in childhood. To do so, a more accurate measure of hyperfiltration is needed than SCr.