BACKGROUND : Generally speaking, anesthesia is often used in gravid body and it has been already proved that many kind of medicine can result in malformation.OBJECTIVE: To explore embryonic skeleton development and neonatal leing and memory of rats anesthetized with pentobarbital sodium in gravid rats.DESIGN: A randomized control trial.SETTING: Laboratory Animal Center of Xuzhou Medical College.MATERIALS: A total of 80 adult female SD rats, of clean grade and weighing 220-240 g, were selected in this study. The main reagents were detailed as follows: pentobarbital sodium (Shanghai Xingzhi Chemical Plant,batch number: 921019); MG-2 maze test apparatus (Zhangjiagang Biomedical Instrument Factory);somatotype microscope (Beijing Taike Instrument Co., Ltd.).METHODS: ① A total of 160 SD rats of half males and females were selected in this study. All rats were copulated. The day that the plug was checked out in the vagina next day was looked as the first day of pregnancy. Gravid rats were divided randomly into four groups, including early anesthesia group, second anesthesia group, late anesthesia group and control group with 20 in each group. Rats in the early anesthesia group were injected with 25 mg/kg soluble pentobarbitone on the 7th day of pregnancy for once; rats in the second anesthesia group were anesthetized with 25 mg/kg soluble pentobarbitone on the 7th and the 14th days of pregnancy for once; rats in the late anesthesia group were anesthetized with 25 mg/kg soluble pentobarbitone on the 14th day of pregnancy for once; rats in the control group did not treat with anything. The time of anesthetizing was controlled in 3 to 4 hours and ether was absorbed while the time was not enough. ②Half of each group was sacrificed on day 20th of pregnancy and the fetus was taken out to be stained with alizarin red S. After stained, the fetal skeleton was examined. The leing and memorizing of one-month rats that were given birth by the rest gravid rats were tested through electric mare method. Determine their study ability according to their correct rate of 90% or above of arrival at the safe area in 20 s. After they finally leed to arrive at the safe area correctly, test them once more in 24 hours and record the correct rate of 15 times.MAIN OUTCOME MEASURES: The rate of malformation in fetus and ability of leing and memory in one-month rats.RESULTS: A total of 80 female rats were anesthetized in this experiment. Totally 490 immature rats were tested with maze testing machine and 196 fetuses were stained with alizarin red S to observe the development of their skeleton. However, one of the 80 female rats was led to death because of overdose. ① Malformation experiment: Leing ability of second anesthesia group was evidently different from the control group while the other two groups were not in the electric mare method. The fetal skeleton malformation rate of three experimental groups was 87.0%, 60.9% and 17.9%, respectively, while it was 5.6% in the control group. ②Electric mare method: Times of rats which arrived at the safe regions were respectively 49.0±31.0, 68.0±35.0,47.0±31.0 and 44.0±21.0 in early anesthesia group, second anesthesia group, late anesthesia group and control group; and then, there was significant difference between the second anesthesia group and the control group (P ＜ 0.05). Exact rates of memory of rats were respectively (64.36±14.35)%, (62.15±18.33)%, (54.19±12.28)% and (68.24±15.91)% in early anesthesia group, second anesthesia group, late anesthesia group and control group; and then, there were no significant differences as compared with the control group (P＞ 0.05).CONCLUSION: The influence of anesthesia with pentobarbital sodium is obvious in fetal skeleton development and leing and memory ability.