Lack of association between Rh status, Rh immune globulin in pregnancy and autism

Abstract

Though causes of autism are considered largely genetic, considerable concern remains that exposure to Rh immune globulin (RhIg), which until 2001 in the United States contained the preservative thimerosal, can cause autism. To determine whether mothers of children with autism are more likely to be Rh negative (Rh−) or to have received RhIg preserved with thimerosal, which is 49.6% ethyl mercury, we surveyed families of children with an autism spectrum disorder (ASD) ascertained through a University‐based autism clinic considered free of ascertainment biases related to type of autism or severity. Between 2004 and 2006, 305 mothers of 321 children with an ASD agreed to participate in a telephone interview. Analysis of complete records including the blood group status and RhIg exposure of 214 families showed that Rh− status is no higher in mothers of children with autism than in the general population, exposure to antepartum RhIg, preserved with thimerosal is no higher for children with autism and pregnancies are no more likely to be Rh incompatible. This was also true for autism subgroups defined by behavioral phenotype, gender, IQ, regressive onset, head circumference, dysmorphology, birth status, essential, or complex phenotype. These findings support the consensus that exposure to ethylmercury in thimerosal is not the cause of the increased prevalence of autism. These data are important not only for parents in this country but also for the international health community where thimerosal continues to be used to preserve multi‐dose vials which in turn makes vaccines affordable. © 2007 Wiley‐Liss, Inc.

Genetic and Environmental Factors in Autism

“…The relationship between exposure to Rh immune globulin, which contained the preservative thimerosal until 2001 in the United States, and autism has also been investigated; however, no significant association has been revealed between exposure of antepartum RhIg preserved with thimerosal and an increase in risk of autistic disorder. The latter findings are in accordance with the consensus that exposure to ethymercury in thimerosal is not the cause of increased prevalence of autism [118].…”

Systematic Assessment of Research on Autism Spectrum Disorder (ASD) and Mercury Reveals Conflicts of Interest and the Need for Transparency in Autism Research

“…However, Johnson & Johnson, a manufacturer of RhoGAM, approached Judith Miles at the University of Missouri with a significant grant to help defend the company from litigation (Evaluate™ 2012 ; Osterweil 2007 ; Wikipedia 2017 ). The industry-sponsored study by Miles and T. Nicole Takahashi ( 2007 ) commenced and concluded that exposure to ethylmercury (or Thimerosal) from RhoGAM was not associated with ASD (Miles and Takahashi 2007 ).…”

Continuing Increases in Autism Reported to California's Developmental Services System

“…In one of these studies, Hviid and colleagues 16 found that the prevalence of autism in Denmark increased from 1991 through 1996 despite the exclusion of thimerosal in routine childhood vaccines. Epidemiologic data [31][32][33] published after the IOM Immunization Safety Committee report also fail to support a causal relationship between thimerosal exposure and autism. Fombonne and colleagues 32 recently calculated the prevalence of pervasive developmental disorders in more than 27 000 students in the greater Montreal area of Quebec, Canada, born from 1987 through 1998.…”

“…Although vaccinations have been the primary source of exposure to thimerosal in childhood, a small proportion of young children during the study period would have had additional thimerosal exposure in utero through maternal immunization during pregnancy with vaccines or Rh o (D) immune globulin. 33 Similarly, sources of methylmercury exposure such as fish or human milk could not be evaluated.…”