Maternal and paternal chronic exposure to enflurane and halothane: fetal and histological changes in the rat

Adult male and female rats were exposed chronically to halothane 10 p.p.m., enflurane 20 p.p.m. or air for up to 64 days before mating and subsequently throughout the pregnancy of the females. The parents, progeny and, in a few cases, the subsequent generation, were studied. No abortifacient effect was seen with either agent. The groups exposed to anaesthetic had larger litters with lighter fetuses compared with their control groups. Skeletal examination did not reveal any major teratological effects for either agent. No consistent organ injury could be associated with chronic exposure to the agents under the conditions of this study.