Fetal Doppler Vs. Ultrasound Frequencies & Dangers

Pregnancy

Fetal Doppler and ultrasound technology allow doctors the unparalleled opportunity to view developing fetuses inside the womb. The safety, however, of these devices is coming into question more and more, causing many parents to educate themselves on the risks of these procedures before undergoing them.

Fetal Doppler

Fetal Doppler monitoring devices operate at 2 to 3 MHz, which are completely focused and concentrated to allow doctors to clearly hear the flow of blood through the heart.

Ultrasound

Ultrasound frequencies are typically around 12 MHz, but are not focused on any particular organ.

Cavitation

According to Dr. Sears, pediatrician and author of "The Birth Book," "When sound waves bombard laboratory tissues at high frequencies, they shake up the molecules, heat them, and produce microscopic gas bubbles in the cell called 'cavitation.' Whether this heat or these bubbles damage the cell is unknown, although studies suggest that the changes demonstrated in research test tubes are insignificant in babies."

Growth Retardation

A study conducted in Britain determined that babies exposed to five or more Doppler ultrasounds had a 30 percent risk of having intrauterine growth retardation.

Benefits

Doppler and ultrasound technology enable physicians to detect birth detects and possible complications early in a pregnancy, giving them the ability to offer parents more options and possibly correct some of the problems.

References

• Fetal Doppler Facts
• GE: Ultrasound Facts
• Midwifery Today: Ultrasound

Resources

• Dr. Sears
• FDA: Ultrasound Warnings