Antepartum periodontitis treatment and risk of offspring screening positive for autism spectrum disorder

Background To evaluate if treating maternal periodontal disease, a pro-inflammatory condition, during pregnancy (intervention) compared to after pregnancy (control) reduces the likelihood of offspring screening positive for autism spectrum disorder (ASD). Methods In a follow-up study to the MOTOR randomized trial, we compared rates of positive screens on the Modified Checklist for Autism in Toddlers (M-CHAT) among n = 306 two-year-old toddlers and correlated findings to maternal and cord blood pro-inflammatory interleukin-6 (IL-6). Results Toddlers in the intervention group had decreased risk of a positive M-CHAT screen (adjusted RR = 0.53, 95% CI 0.29–0.99). Toddlers screening positive compared to negative had higher mean IL-6 in cord blood (1.58 ± 1.14 vs. 1.09 ± 0.72 p = 0.001) and maternal IL-6 change from baseline (1.30 ± 0.61 vs 0.96 ± 0.62 p = 0.03). Conclusions Treating periodontal disease during pregnancy reduced risk of a positive ASD screen. M-CHAT positivity was associated with increased IL-6 in maternal and cord blood. Clinical trial Trial Registration numbers: Clinicaltrials.gov NCT03423836.