초음파 Doppler 태아심박확인기에 의하면 임신12주이후에 음성이면 태아사망이 확인된다.

An ultrasonic Doppler instrument (made in Japan, Fukuda Co.; Model/pu-1) was used to provide a quick safe method to obtain audible signals of fetal heart tones by means of a small tranducer(diameter 25mm) on the pregnant abdominal wall. 1) Of 118 observations the fetal heart tones have been detected as early as 7 weeks and consistently detected at 12 weeks or more after the first day of the last menstual period. 2) This instrument would seem to have practical value in selected patients in whom detection of intrauterine life from after 12 weeks gestation is important for clinical management. 3) Use of this instrument for prenatal placental locatization appears to be reliable and practical.