I went to the doctor today for bleeding and the women used a fetal Doppler to see if she could hear the heartbeat. She did (I didn’t) 😞. I asked her if they are safe to use and she does not really. She said occasional use is fine but it has been tested on pregnant rats and issues have risen with constant use. I have one so my husband hid it from me so I can’t use it. I know a lot of people have one and they are tempting to use.