EN
Administration intraperitoneally of the Ascaris suum extract - ASE-(0.6-1.4 g of Ascaris proteins/kg/day) at a late stage of organogenesis (8-12 days of gestation) disturbed course of mouse pregnancy. lt has been found that injections of higher doses of ASE to pregnant mice caused the symptoms manifesting maternal toxicity (decreased body weight gain /p < 0.001/ as compared to control, intrauterine resorption of litter, vaginal hemorrhages, female mortality and altered behaviour). There is a linear interrelationship between the logarithm of the dose of ASE and mortality of pregnant mice. The DL₅₀ value of Ascaris proteins for pregnant mice was 1.02 g/kg/day (confidence interval 0.97-1.07 g/kg/day). ASE exerted embryotoxic effects: significantly decreased the number of surviving fetuses per litter and the mean body weight of fetuses, increased the number of fetal resorptions.