[A preclinical study of the embryotoxic properties of cucumarioside and its effect on adult generative function]. The preclinical study of embryotoxicity of a new immunomodulator cucumariosid was carried out. Cucumariosid at long-term use exerts no effect on the generative function of rats, the general condition of pregnant females and the postnatal development of the offspring, possesses no teratogenic action. The use of the drug in the preimplantation period of pregnancy and the implantation period produces the contraceptive effect.