Kim StrifertIt is now conservatively estimated that 1 in 68 children are diagnosed with ASD in the United States. So far, no definitive cause or contributing factors have been established to account for the increase in prevalence in ASD. Combined Oral Contraceptive (COC) use is one possible risk factor for the increase in prevalence that has been overlooked in the existing biomedical and epidemiologic literature. This hypothesis is compelling due to several considerations. As the prevalence of COC use has raised so has the prevalence of ASDs. As a category of agents there are specific documented mechanisms through which COCs can affect the oocyte and/or developing embryo. As COCs are taken deliberately, exposure occurs at pharmacologically effective concentrations. The possibility exists that the effects of COC use could intensify over generations due to transgenerational transmission of altered epigenetic programming, with continued exposure across generations imparting sensitivity to developing ASDs. Lastly, the specific demographic at risk, women who are likely to have children, is the exact demographic that is taking COCs. This article calls for epidemiological investigation into the association between COC use and ASD in offspring using the Norwegian Mother and Child Cohort Study and its subset the Autism Birth Cohort.