坂元 正一¹, 椋棒 正昌¹, 岡井 崇¹, 原 量宏²

Shoichi SAKAMOTO¹, Masaaki MUKUBOH¹, Takashi OKAI¹, Kazuhiro HARA²

¹東京大学医学部産科婦人科学教室, ²香川医科大学周産期医学教室

¹Department of Obstetrics and Gynecology, Faculty of Medicine, University of Tokyo, ²Department of Perinatology, Obstetrics and Gynecology, Kagawa Medical Collage

キーワード : pulsed ultrasound, pregnant mouse, epidemiology

Experimental Study: ICR strain pregnant mice were exposed to 2 MHz pulsed ultrasound for 5 minutes at the 8th day of gestation. The pulse width was 180 μs, the repetition frequency 150 Hz and the average intensities 50 mW/cm² and 600 mW/cm². In the group exposed to pulsed ultrasound with an average intensity of 600 mW/cm² , a higher incidence of fetal malformations was found than in control group, but the group with 50 mW/cm² showed no significant difference from control.
Epidemiological Study: The analysis and comparison were done on the incidence of birth defects at three consecutive periods (1978-1980: when real time scanner-pulsed ultrasound was used,1969-1974: when Doppler-continuous wave was used and 1966-1968: when ultrasonics were not used at Tokyo University Hospital). No significant difference was found in the incidence of birth defects between these three periods. It was suggested that pulsed ultrasound had no jeopardizing effect on fetuses, as long as it was used with such a low intensity as in clinical application.