Effect Of Color Doppler Ultrasound During Different Durations Of Pregnancy On Offspring' Brain Function

Objective: To observe postnatal behavior development of rats and to evaluate offspring' learning and memorizing abilities by Morris water maze after Color Doppler ultrasound exposure during different durations of Pregnancy. Then investigate whether Color Doppler ultrasound exposure during different durations of Pregnancy could affect Offspring'Brain Function.Materials and methods:Thirty pregnant SD rats were randomly divided into three groups according to the exposure time: control group (0 min group), 10 min group and 20 min group. The rats were exposed to continuous ultrasound (3.0 MHz, MI=1.6, TI=1.8) on 6th ,12th ,and 18th days of gestation. Neuro-behaviora1 development of offspring was assessed by observation of offspring's behavior performance. In each group 90 days old neonatal rats were selected to do Morris water maze test. By analyzing the averaged escape latencies to the plate, the ratio of time spent in the target quadrant and the number of crossing the plate, learning and memory abilities were evaluatedResults:Time of air righting and visual placing of 20 min group [(13.1±0.9) d,(16.0±0.8) d] appeared later than these of control group [(12.1±0.8) d,(15.1±0.7) d] (P<0.05), however there were no difference among the 3 groups(P>0.05),such as: pinna detachment,eye opening,surface righting and auditory startle. The escape latencies of rats in 20 min group [(27.74±4.90) s,(21.42±3.87) s] were significantly longer than those of the control group([17.74±2.96) s,(14.86±3.64) s] (P <0.05), the time spent percent in the target quadrant and the numbers of crossing the plate in 20 min group (27.06%±4.25%,1.75±0.36) were significantly lower than those of the control group (37.42%±3.02%,4.16±0.41); whereas there were no differences between the 10 min group and the control group(P>0.05).Conclusions:There were no effect of postnatal behavior development and learning and memorizing abilities of rats after Color Doppler ultrasound exposure 10 minutes during different durations of Pregnancy. Doppler ultrasound over 20 min radiation may affect not only offspring' learning and memorizing abilities, but also postnatal behavior development of rats. It may be safe that exposure to color Doppler ultrasound less than 10 minutes every time during different durations of Pregnancy. Radiation more than 20 minutes every time may affect Offspring'Brain Function. The experiment suggests in obstetrics sonography that we should decrease frequency and reduce time in order to degrade and avoid affect of ultrasound.