Dose of 1.5 and 4.0 mg/kg/day of HEOD in corn oil and 0.25, 0.5 and 1.0 mg/kg/day of HEOD in dimethyl sulphoxide (DMSO) were administered to pregnant CF1 mice on days 6 to 14 (inclusive) of gestation. Some maternal and foetal toxicity was seen in the HEOD in DMSO and DMSO control groups compared with the untreated controls, such as reduced body weight gains, some maternal deaths, lower foetal body weights and increased incidence of delayed ossification of the foetal bones. No maternal or foetal toxicity was seen in the HEOD in corn oil or the corn oil control groups. No compound-related teratogenic effects were observed.