Abstract
Four types of reproductive toxicity evaluations exist. These significantly differ from all other toxicity studies. Studies are “driven” by the timing or occurrence of mating, pregnancy, abortion, natural delivery, litter size, and viability of offspring. Unique identification of at least two generations and parental historical data are required. Specialized randomization procedures must be used because mating performance determines selection of test animals. Simultaneous recording of multiple data, embryo-fetal-pup units and correlation of these data with parental data must occur. For example, C-sectioning observations must include adult necropsy observations and uterine weights as well as fetal body weights, crown-rump measurements, uterine placement, identification, viability, gender, and gross external anomalies. Correlations must include parental mortality, adverse clinical signs, fertility, body weight changes, food consumption, duration of gestation, duration of delivery, and nursing behavior with embryo death, fetal death, fetal body weight (litter), fetal sex ratio, pup viability and behavior, pup body weights (litter), postnatal adverse clinical signs, and postnatal functional effects (“behavior, ”fertility). Litter identification of offspring, even post-weaning, is necessary. Data should be summarized on the basis of the unit evaluated. For Segment I studies, both adults and litters should be examined, and pup “behavior” evaluated on the basis of the litter (preweaning), and the individual animal (postlactation). In Segment II studies, the units are pregnant animals and viable litters. Segment III studies evaluate pregnant dams (preparturition), dams with surviving pups (postparturition) and litters, with pup “behavior” evaluated as in Segment I studies. Reproduction studies have continual variation of the evaluation units.
Get full access to this article
View all access options for this article.