The study Teratogenic effects of hyperthermia on rat

Background: The hyperthermia is the increase in mammalian’s body temperature above normal that affects the embryo during the critical stage of gestational term and may cause some congenital malformations. Objective: The aim of this study was understanding the teratogenic effects of hyperthermia on the rat embryonic development. Methods: In this study 50 female rats of Sprague Dawley strain were used and their body temperature was determined by rectal measurement. Then female pregnant rats were divided to seven groups (one control group and six experimental groups). The female pregnant rats from 9 to 14 days of gestation, were put in the incubator in three stage during a day and were remained in the incubator for 10 minutes on 850C that their body temperature increasted to 410C. Rats in control group were put in incubator at similar situation except the temperature which was kept on 400C to increase only 10C to their body temperature. Then, on 20th day of gestation their fetuses were taken out and examined. Findings: Results showed that congenital malformations such as microphthalmia, anophthalmia, maxillary hypoplasia, IUGR and fetal death were observed in the groups that affected by hyperthermia on the days 9,10 and 11. Conclusion: Hyperthermia is a teratogenic factor which its effects in organogenic period causes congenital malformations.