Pulsed Doppler Ultrasound in First Trimester

[cheykath]

I was 10 weeks 3 days pregnant on June 21st when I went for my second prenatal visit.  The nurse was unable to find the baby's heartbeat using the hand-held doppler, so she told me my doctor would need to do a "tummy scan."  I assumed there was a good reason to do an ultrasound, even though I have already had two earlier ultrasounds (one at 5 weeks because of abdominal pain) and one at 8 weeks to confirm the pregnancy since no fetal pole was found at the first ultrasound.  So at the 10 week visit, the doctor used the doppler button on the ultrasound machine to hear the baby's heartbeat and produce a visible waveform on the ultrasound screen.  I had a very bad feeling about it, and went home and did some research, only to find, to my horror, that pulsed wave doppler ultrasounds are really not supposed to be performed in the first trimester because they are so much more powerful than regular ultrasounds.  I called my doctor and spoke to her about my concerns, but she pooh-poohed my worries saying that she "does it all the time."  She did not seem to be very familiar with the different modes of ultrasound and said she "didn't understand my question" when I asked her if she had used pulsed-wave ultrasound on me.  I am certain that she did because it is the only form of ultrasound that produces an audible sound.  My question is this:  just how worried should I be?  Is it likely that harm was done to my baby?  Thanks in advance for any help you can offer!

[Melvista]

technician just did my first ultrasound at six weeks because I had gone through Ivf and she didn't tell me she was using Doppler, I only realized when she eventually showed me the screen. I worried as I'm only six weeks and it shouldn't be used this early. The embryo had a healthy heartbeat of 115 and was the exact size it should be according to the date of embryo transfer.

[Melvista]

I just had a six week ultrasound because I went through Ivf and there was a lovely strong heartbeat and the embryo was exactly the size it should be. the technician used Doppler, but I don't know why she did as I didn't ask her to and I would have told her not to if I had known what she was doing. I'm scared now that she has harmed my little embryo with the high frequency sound waves. The TIS on the ultrasound was 0.5 so it was low, but the MI was 0.7. I am so worried now that she has hurt my embryo

[Sadlershelly]

I am an ultrasound student. This is a common question we get from OB patients. Pulsed wave Doppler (which produces) audible sounds is perfectly safe. The only reason most OB places do not do them is because of the ultrasound motto which is "ALARA" as low as reasonably achievable. This simply means that there is no evidence to prove that ultrasound has any effect on the body let alone any negative effect, however, has a medical imaging modality we have to take every precaution. Since pulsed wave Doppler is a higher frequency than our regular transducers, we prefer to use it as little as possible. But again, there is no evidence of any negative effects on the patient or the fetus. It is completely safe as long as it is not used for hours and hours without any breaks. Do not worry yourself! I just had to reassure my 8week pregnant sister of the same thing.

[minney930]

Pulsed wave U/S is less than continuous wave... Those handheld pocket dopplers are continuous wave. There are so many variables to this "danger" regarding exposure. Different probes have different frequencies. There could be harm done if a vascular probe is used in one spot continuously for hours and hours on end. The OB probes are usually 1/4 the frequency of vascular probes and not used for very long at all. Think of putting a radio to your tummy for a little bit. Don't be surprised when your 20 week anatomy scan takes an hour or so, and if that happens don't worry... Still safe low frequencies that are constantly moving. (As a hint: if there is a picture, it is pulsed wave not continuous).  With the embryo being so small in the first trimester, most the time doctors can only see the heart with U/S in order to measure the heart rate. You don't have to question you doctors ability because she didn't understand your question... Most doctors learn how to use the imagers (and use them safely), but few of them learn the physics and Doppler principles that go along with it. Good luck with your pregnancy!

[cheykath]

Thank you so much everyone - you really put my mind at ease!  Blessings to all of you.  :)

Cheykath

[alaysha]

I had an ultrasound every other week even in the first trimester because I was high risk and bleeding. First time I heard her heartbeat was at one at 6 weeks. She is 100% okay! :)

[Melka76]

I have had that type done with all three of my children in the first, second and third trimester since I was high risk for all three - I have a healthy 8 year old, 5 year old and 1 week old... I would not worry about it. Good Luck

[cheykath]

Hi Alaysha,

Thanks for writing!  That is very reassuring.  I do have one question:  did they do that type of ultrasound in the first trimester with your 2 1/2 year old?

Cheykath

[alaysha]

Its pretty standard for any ultrasound you get since they need to have that information. Although they can see the flickering of the heart rate via regular ultrasound they cannot tell if it is what would be considered "normal" unless they hear it and can make a determination. I've had about 5 ultrasounds this pregnancy and they've done it every time. I also had like bi-weekly ultrasounds during my last pregnancy and they did it then too. My 2 1/2 year old is perfect and incredibly smart and I'm 25 weeks now and everything seems to be developing right.

[neecy28411]

do u mean like when hey do an ultrasound then make it to where u hear the heartbeat too? they did that to me with my other pregnancy i didnt know it was bad but i think you will be okay i was around 8 weeks when they did it maybe a little less.