Maternal Rh D status, anti-D immune globulin exposure during pregnancy, and risk of autism spectrum disorders

OBJECTIVE: The objective of the study was to investigate the association between maternal Rh D status, prenatal exposure to anti-D immune globulin, and the risk of autism in the offspring. STUDY DESIGN: Case-control study among children born from 1995 to 1999 at Kaiser Permanente Northern California hospitals. Cases (n = 400) were children with an autism diagnosis; controls (n = 410) were children without autism, randomly sampled and frequency matched to cases on sex, birth year, and birth hospital. Maternal Rh D status and anti-D immune globulin exposure were ascertained from prenatal medical records. RESULTS: No case-control differences were observed for maternal Rh negative status (11.5% vs 10.0%, P =.5) or prenatal anti-D immune globulin exposure (10.0% vs. 9.3%, P =.7). Risk of autism remained unassociated with maternal Rh status or prenatal exposure to anti-D immune globulins after adjustment for covariates. CONCLUSION: These data support previous findings that prenatal exposure to thimerosal-containing anti-D immune globulins does not increase the risk of autism.