Teratogenic evaluation of butyl benzyl phthalate in rats by gastric intubation.

Pregnant rats were given butyl benzyl phthalate (BBP) by gastric intubation at a dose of 0, 0.5, 0.75 or 1.0 g/kg on days 7-15 of pregnancy. In the 0.5 g/kg group, food consumption during the administration period was significantly decreased, but no adverse effect on the embryo-fetus was detected. High maternal lethality and complete resorption of implanted embryos in all the surviving dams were observed in the 1.0 g/kg group. Increased embryo-fetal death and decreased fetal weight were found at a dose of 0.75 g/kg which also caused reductions in maternal body weight gain and food consumption. A significantly and markedly increased incidence of fetal malformations was also detected in the 0.75 g/kg group. Cleft palate, fusion of the sternebrae and dilatation of the renal pelvis were mostly observed.