Abstract
The effect of 1,3‐butanediol on reproductive performance as well as its teratogenic, dominant lethal and cytogenetic effects were studied in five generations of Wistar rats. Animals of both sexes were fed either control diet or diet supplemented with 1,3‐butanediol at dose levels of 5, 10 or 24% of the diet by weight. Reproduction and lactation parameters were comparative to controls for four of five generations of dams and pups. In contrast, the pregnancy rate of F1A rats decreased during five successive mating cycles; no pups were obtained in the high‐dose level group of the fifth series of litters (F2E generation). Excluding this group, the viability of F2 generation pups revealed no significant differences between litters or between control and test groups. No definitive dose‐related teratological findings were found in either soft or skeletal tissue examinations of F3B generation rats. However, incomplete ossification of sternebrae occurred frequently in mid‐ and high‐dose fetuses, whereas missing sternebrae were noted especially in high‐level fetuses. Both skeletal tissue findings suggest slight delayed fetal growth. For the dominant lethal assay of the F1B generation, the mutagenic index (percentage resorptions per implant sites) revealed no dose‐related trend. In the three‐generation cytogenetic study, no 1,3‐butanediol related chromosomal aberrations were noted.