How a Fetal Doppler Works?
Despite that I knew doctors used fetal monitoring equipment, I was unsure as to how it was accomplished and how it was possible to mimic the same sort of results using a more simplistic, hand-held device. I learned that Fetal dopplers work on the principle of Doppler effect, discovered in 1842 by a famous Austrian mathematician and physicist Christian Doppler (1803-53). Doppler discovered that when high-frequency sound waves are reflected from a moving object, their frequency change and this can be analyzed.
Each fetal doppler contains a transducer or a probe which sends out short pulses of ultrasound sound waves into the directed area of the body. When these sound waves are reflected from the baby’s beating heart, their frequency change. When this echo is received by the fetal doppler, it converts this signal into the baby’s heartbeat. Normally a speaker or an auxiliary jack of earphones is connected to the doppler through which one can hear the heartbeat.
When Can I Begin Using a Fetal Doppler?
In seeking information on how soon one can begin to use a fetal doppler to monitor their child’s heartbeat with accuracy, I found a handy chart that answered all of my questions. To begin with, let me clarify that fetal heartbeat cannot be detected for the first 8 to 10 weeks. In certain cases, it can be delayed for up to 12 weeks depending on factors that include fetal position, the shape of the mother’s uterus, and the pre-pregnancy weight of the mother. For a normal fetus, by week 8 the heartbeats should increase from 149 beats per minute to 172 beats per minute. After that the heart rate changes in the weeks after and by week 9 it should become more stable, ranging from 155 beats per minute to 195 beats per minute. However, after week 9, fetal heart rate begins to fall, reaching levels between 120 to 160 beats per minute by week 12.
Let me state here again that a fetal doppler does not and cannot diagnose any fetal problem and that you should consult with your doctor during on any issue. It is just a device to help you listen to your baby growing inside of you and provide a unique bonding experience. A word of caution here as to that it takes time and practice to be able to start to identify correctly the baby’s heartbeat as often one can be mistaken initially what they hear using a fetal doppler.
What Sounds Can Be Mistaken for a heartbeat?
It is not uncommon to misinterpret the baby’s heartbeat by an inexperienced or a first time user. Any movement involved in the function of the mother’s bodily systems can inhibit the accurate representation of fetal heart rate. Whether it be the mother’s own heartbeat, digestive processes, or arterial blood flow, fetal dopplers translate all microscopic movements into audible sounds; thus, any other movement can skew the results. In fact, even fetal movements such as rolling or kicking can create whooshing sounds or clicks that may mask or change the sound emitted by the doppler device. Because of this, mothers are advised to use the device in the right way and be able to identify correctly the heartbeat of the baby and not to get tense. By practice, you should be able to do that in no time!
What to Consider When Purchasing a Fetal Doppler?
There are many fetal doppler devices available on the shelf but as I had mentioned in my last post, not all of them are safe and recommended by the FDA. You should buy only FDA recommended fetal dopplers as they adhere to the specifications and guidelines considered safe by FDA. Fetal doppler devices are categorized by the frequency of sound waves they use. Most common types work on 2 or 3 MHz frequency and both work equally well. The 3 MHz models are more sensitive and more accurate at detecting a fetal heartbeat in early stages of pregnancy. That said there are cases where a 2 MHz device may work better. Capable of detecting movements at a greater depth than 3 MHz models, 2 MHz devices are ideal for mothers who are overweight, for instances where the fetus lies closer to the rear of the uterus, in situations where the placenta is located in front of the fetus, and in the later stages of pregnancy when heightened sensitivity is not as necessary.
It was 4 years and two pregnancies ago that I discovered the joys of using a fetal doppler to enhance my pregnancy experience and there was never a moment when I felt the tiniest tinge of regret. In fact, I have become an avid supporter of fetal dopplers. A few years ago when my friend found herself filled with anxiety about becoming pregnant again, not long after an emotionally-trying miscarriage, I recommended her fetal doppler to give her peace of mind and calm her nerves. It worked like a charm for her and if you are an expectant parent reading this article, I would recommend to you to use a fetal doppler without any worry and experience the joys of gestational bonding with your baby. It is one decision which you can be thankful to me your entire life.