Fetal acoustic stimulation as a possible adjunct to diagnostic obstetric ultrasound: a preliminary report

Unfavorable fetal position during diagnostic obstetric ultrasound can interfere with visualization of certain structures, leading to prolonged or repeated examination. Fetal acoustic stimulation induces a fetal startle reflex and an increase in fetal movements. This report describes our experience with fetal acoustic stimulation to prompt fetal movement in an effort to improve fetal visualization. At gestational ages of 28 weeks or more a 94.1% success rate was noted, in 30 seconds or less in 70.6% of the cases. We conclude that fetal acoustic stimulation may be a valuable adjunct to diagnostic obstetric ultrasound.