Thursday, December 11, 2008

Fetal Doppler

A Doppler fetal monitor or Doppler fetal heart rate monitor is a hand-held ultrasound transducer that uses the Doppler effect to detect the heart beat of a fetus and provides an audible simulation of the heart beat.

And Some models also display the heart rate in beats per minute. and Use of this monitor is sometimes known as Doppler auscultation.
A Doppler fetal monitor provides information about the fetus similar to the information a fetal stethoscope provides. One advantage of the Doppler fetal monitor over an acoustic (not electronic) fetal stethoscope is the audio output, which allows people other than the user to listen to the heartbeat. And the One disadvantage is the greater complexity and cost, and lower reliability, of an electronic device.
Originally intended for use by health care professionals, this device is becoming popular for personal use.

Fetal heart rates
Starting at week 5 the fetal heart will accelerate at a rate of 3.3 beats per day for the next month.
The fetal heart begins to beat at approximately the same rate as the mothers, which is 80 to 85 bpm. Below illustrates the approximate fetal heart rate for weeks 5 to 9, an assuming a starting rate of 80
Week 5 starts at 80 and ends at 103 bpm
Week 6 starts at 103 and ends at 126 bpm
Week 7 starts at 126 and ends at 149 bpm
Week 8 starts at 149 and ends at 172 bpm
At week 9 the fetal heartbeat tends to beat within a range of 155 to 195 bpm.
The fetal heart rate will begin to decrease and generally will fall within the range of 120 to 160 bpm by week 12.

Gender prediction
Evidence indicates that there is no relationship between fetal heart rate and fetus gender, and thus fetal heart rate cannot be used as a reliable predictor of the sex of a fetus.

Types of Dopplers
Dopplers for home or hospital use differ in the following ways:
1) Manufacturer - popular manufactures are Huntleigh, LifeDop, Stork Radio, and Nicolette
2) Probe type - waterproof or not. Waterproof probes are essential for water births.
3) Megahertz frequency - 2 or 3 megahertz probes. Most women can find the heart rate with either 2 or 3 megahertz probes. A 2 megahertz probe is recommended to detect a heart rate in early pregnancy (8-10 weeks), A 3 megahertz probe is recommended for women who are plus sized and pregnants.
4) Heartrate Display - some dopplers automatically display the heart rate, and for others the fetal heart rate must be manually counted.

No comments: