[Use of fetal ultrasonic detectors in general practice]

50 general practitioners (GPs) in Norway answered a questionnaire on their use of ultrasonic fetal heart detectors in 1979-80 and 1989. 21 of 50 GPs (42%) had an ultrasonic fetal heart detector in 1979-80, and 32 of 44 GPs (73%) had such a device in 1989 (p less than 0.01). The use of the detector had not changed much over the years. 85% of the doctors who had such a device used it on all or most pregnant women. 70% of the GPs usually listened to the fetal heart beat for 10-30 seconds each time, and about 1/3 of the GPs used the detector more than eight times during each pregnancy. There was a linear relationship between the GPs' conception of the energy output level of the fetal heart beat detector and his/her use of the instrument. GPs who believed the device to have a relatively high energy output level compared with standard B-scan equipment used the device for shorter time periods (r = -0.49, p less than 0.05) and less often during pregnancy (r = -0.54, p less than 0.01).