The Link Between Oral Contraceptive Use and Prevalence in Autism Spectrum Disorder

Autism spectrum disorder (ASD) is a group of developmental disabilities that include full syndrome autism, Asperger's syndrome, and other pervasive developmental disorders. The identified prevalence of ASD has increased in a short time period across multiple studies causing some to conclude that it has reached epidemic proportions in the U.S. Many possible explanations for the rise in numbers of individuals diagnosed with ASD have been offered and yet, causes and contributing factors for ASD are inadequately understood. Current evidence suggests that both genetics and environment play a part in causing ASD. One possible risk factor for the increase in prevalence has been profoundly overlooked in the existing biomedical and epidemiologic literature. As the prevalence of ASD has risen in the last sixty years, so has the prevalence of the usage of the oral contraceptives and other modern hormonal delivery methods. In 1960 about one million American women were using oral contraceptives, today close to 11 million women in the U.S. use oral contraceptives. Eighty-two percent of sexually active women in the U.S. have used oral contraceptives at some point during their reproductive years. Thus, the growth in use of progesterone/estrogen-based contraceptives in the United State has reached near-ubiquitous levels among women in the child-bearing age range. The suppression of ovulation produced by estrogen-progesterone is an indisputable abnormality. It is logical to consider the outcome of the ovum that would have been normally released from the ovary during ovulation. To date there is no comprehensive research into the potential neurodevelopmental effects of oral contraceptive use on progeny. The issue has been only sparsely considered in the biomedical literature. This article hypothesizes that the compounds, estrogen and progesterone, used in oral contraceptives modify the condition of the oocyte and give rise to a potent risk factor that helps explain the recent increase in the prevalence of ASD's. This hypothesis does not propose to delineate the cause of autism. Rather, it attempts to explain the recent dramatic increase in prevalence and point the way for further study that will lead to causal examination.