Fig. 2.

Putative critical windows of developmental vulnerability for autism are shown based on reports involving potential environmental risk factors. Information is included from human studies as well as from animal data. References for each risk factor and window are as follows: Viral Infection—Hospitalization (92), Absence of Food Aversion and Vomiting (44), Misoprostal (70), Thalidomide (109), Valproic Acid (37), Bacterial Infection—Hospitalization (92), Murine Viral Infection (110), Generalized Maternal Stressors (102), Terbutaline (111), and Vitamin D Deficiency (77).