Adverse effects of diphenyltin dichloride on initiation and maintenance ofpregnancy in rats

The objective of this study was to characterize the adverse effects of diph enyltin dichloride (DPTCl) during early pregnancy. Following successful mat ing, female rats were given DPTCl by gastric intubation at 0, 4.1, 8.3, 16. 5, 24.8 or 33.0 mg/kg on days 0-3 or days 4-7 of pregnancy. Female rats wer e sacrificed on day 20 of pregnancy and pregnancy outcome was determined. T he pregnancy rate was significantly decreased after administration of DPTCl on days 0-3 at 24.8 mg/kg and on days 4-7 at 33.0 mg/kg. The incidence of preimplantation loss was significantly increased after administration on da ys 0-3 at 16.5 mg/kg and above and on days 4-7 at 33.0 mg/kg. In females ha ving implantations, the numbers of implantations and live fetuses and the i ncidences of pre- and postimplantation loss in the groups given DPTCI on da ys 0-3 were comparable to the controls. The incidence of postimplantation l oss was significantly increased after administration of DPTCl on days 4-7 a t 33.0 mg/kg. A pair-feeding study revealed no evidence of pre- and postimp lantation embryolethality induced by food restriction. It could be conclude d that DPTCI during early pregnancy causes early embryonic loss and DPTCl h as greater effects on reproduction when administered during earlier than la ter stages of blastogenesis. (C) 1999 Elsevier Science Ireland Ltd. All rig hts reserved.