Toxic effects of butyltin trichloride during early pregnancy in rats

The objective of this study was to determine the toxic effects of butyltin trichloride (BTCl) during early pregnancy. Following successful mating, fem ale rats were given BTCl by gastric intubation at 0, 56, 226, or 903 mg/kg on days 0-3 or 4-7 of pregnancy. Female rats were sacrificed on day 20 of p regnancy and fetuses were examined for number, abnormality, mortality, and weight. The maternal body weight gain and food consumption during the admin istration period was significantly decreased after administration of BTCl a t 903 mg/kg on days 0-3 or 4-7 of pregnancy. The pregnancy rate in the BTCl -treated groups was comparable to the control value, regardless of the days on which BTCl was given. The incidence of pre-implantation embryonic loss was not significantly affected after administration of BTCl on days 0-3 or 4-7. In females having implantations, the numbers of corpora lutea, implant ations, and live fetuses and the incidences of pre- and postimplantation lo ss in the groups given BTCl on days 0-3 were comparable to the controls. Al though a significant increase in the incidence of postimplantation loss was observed after administration of BTCl on days 4-7 at 56 mg/kg, this change was small and inconsistent across doses and seems unlikely to be toxicolog ically significant. A significant decrease in weight of female fetuses was found after administration of BTCl at 903 mg/kg on days 0-3 or 4-7. It coul d be concluded that BTCl treatment during early pregnancy is maternal and d evelopmental toxic at 903 mg/kg. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.