This Test Guideline for developmental toxicity testing is designed to provide general information concerning the effects of prenatal exposure on the pregnant test animal and on the developing organism. The test substance is normally administered to pregnant animals at least from implantation to one day prior to the day of scheduled kill, which should be as close as possible to the normal day of delivery. This Test Guideline is intended for use with rodent (rat preferably) and non-rodent (rabbit preferably). Each test and control group should contain a sufficient number of females to result in approximately 20 female animals with implantation sites at necropsy. Three concentrations, at least, should be used. The test substance or vehicle is usually administered orally by intubation. A limit test may be performed if no effects would be expected at a dose of 1000 mg/kg bw/d. The results of this study include measurements (weighing) and clinical daily observations, each day preferably at the same time. Shortly before caesarean section, the females are killed (one day prior to the expected day of delivery), the uterine contents are examined, and the foetuses are evaluated for soft tissue and skeletal changes. A number of endocrine-related measurements in the dams and in the fetuses have been added in 2018. In any study which demonstrates an absence of toxic effects, further investigation to establish absorption and bioavailability of the test substance should be considered.