Reproduction studies performed in mice at oral doses up to 5,000 times (20 mg/kg/day) and in rats and rabbits at oral doses up to 2,500 times (10 mg/kg/day) the human topical dose have revealed no evidence of teratogenicity due to Voltaren despite the induction of maternal toxicity and fetal toxicity. In rats, maternally toxic doses were associated with dystocia , prolonged gestation, reduced fetal weights and growth, and reduced fetal survival. Voltaren has been shown to cross the placental barrier in mice and rats. There are, however, no adequate and well-controlled studies in pregnant women. Because animal reproduction studies are not always predictive of human response, this drug should be used during pregnancy only if clearly needed.