[QUOTE=WaturMama;7218207]I read in a book that 1 minute of doppler gives the baby the same exposure as 35 minutes of u/s. I'm not going to say where because I am not *totally* sure I have those numbers right, so please check that if it interests you.
I was interested in the numbers, but here is what I found:
"It is important to understand the differences between the hand-held fetal doppler and a sonograph (2D, 3D, or 4D ultrasound). The exposure to ultrasound in sonography (which uses a 3-10mghz transducer) is much higher than that in a hand-held fetal doppler system. Fetal doppler monitors are regulated by the FDA who has set limits on its ultrasound emission. The FDA also regulates sonographs but has recently raised the level of ultrasound 8X higher than its previous standard due to the advent of the new 3D and 4D machines which require higher levels to produce their results."
My OB uses a doppler, and I like the reassurance due to previous M/C. He's really good though and finds it right away (he did the same with DD)... so exposure is less than a minute.
I'm gonna ask him about a fetascope though - I doubt he has one but I am curious if he ever gets asked about it