Doppler Test During Pregnancy – All You Need To Know


What is doppler test during pregnancy?

Is a doppler ultrasound safe for the foetus?

How is it different from a normal ultrasound?

My doctor asked me to do a doppler test. Should I be worried?

doppler test during pregnancy

Carrying a baby for 9 months is no mean feat. But it also means a tonne of worries for new moms. Anytime your doctor asks you to get a test done, it sets of a wave of panic in moms to be. This continues till they get the results saying all is well.

Some moms are worried about tests as they fear it may cause harm to their little one.

You know about dum pukht biriyani? It is cooked in a heavy bottomed pan which is sealed with dough. Till the time the seal of dough is broken and the dish is served, you have no means of finding out whether everything is fine.

Pregnancy would have been just the same, had it not been for the tests and check-ups. Tests during pregnancy helps the doctor to find out if your baby’s growth is progressing in a pace that is normal.

So yes, test performed during pregnancy are important and remember, your doctor will not prescribe a test unless and until he thinks it is important.

Today’s article is about one such test that has made it possible for you to hear your little one’s heartbeat and a host of other test – The Doppler Test.

Ultrasound scans during pregnancy:

 Expecting parents look forward to scans as it is their only way to see their little one before the delivery. But for the doctors, it is way of determining a lot of things.

During pregnancy, ultrasound exams help your gynecologist determine the health of your baby. Let us see the things an ultrasound tells the doctor-

#1. It helps confirm foetal heartbeat

In the initial stages of your pregnancy this is required for the doctor to confirm your pregnancy.
You can also read about the 13 early signs of pregnancy.

#2. It tells the doctor about the progress of your pregnancy

This again tells the doctor if there are any red flags or everything is progressing normally.

#3. Status of umbilical cord

As you know, the umbilical cord is a bridge between the mother and the unborn baby. It provides oxygen and nutrients to the little one and the little one in turn sends back blood devoid of nutrients and oxygen back. It is vital that the umbilical cord doesn’t have any abnormalities as it can affect the health of both the mother and child.

#4. Status of placenta

Just like the umbilical cord, the placenta is also very important for your little one as it is what supplies all the nutrients he/she needs.

Apart from that it helps eliminate wastes, provide oxygen, take out carbon dioxide, protect the baby from infections and secrete hormones required during pregnancy.

Gynecologists use scans to see the location and development of the placenta.

#5. Position of baby

An ultrasound scan will also tell the doctor if the baby’s positioning is right in the womb. According to the position he can also determine when your baby is expected.

#6. General development

It can tell how the baby is developing, his/her growth in terms of length and weight etc.

#7. Health of the mother

Apart from the baby, an ultrasound will also help doctor determine if there are any issues or complications like clots or cysts in the mother that can cause problems before or during labour.

So this picture (sonogram) speaks a thousand words and can help the mother and baby in case there is any problem.

What is a doppler test during pregnancy?

There are various types of ultrasound scans that help determine how the pregnancy is developing. You do not have to undergo all of them. Your doctor will only prescribe what is required according to your stage and state.

Doppler scan is a type of ultrasound scan. A doppler test uses sound waves to check how blood flows through your blood vessels. It shows the rate of blood flow through arteries and veins.

What is the difference between a normal ultrasound and a doppler ultrasound?

A normal ultrasound will not show the rate of blood flow, but a doppler scan will show the rate of the blood flow and blood pressure in placenta, umbilical cord, brain and heart of the baby.

Normal ultrasound scans shows only the image of the baby but Doppler can help you hear the heartbeat and the amount of oxygen and nutrients the baby gets by accessing the blood flow rate.

How does a doppler scan help?

A Doppler scan is not just done during pregnancy. This can be used to check patients for the state of their blood circulation to rule out or find out issues.

The Doppler test can tell the doctors if there is a reduced flow of blood through the blood vessels. Not just that, it can also reveal if there are any blocks or clots in the circulatory system. So a timely intervention due to the Doppler test results can save a person from strokes, embolisms etc.

Likewise a doppler scan during pregnancy can help the doctor find out any issues in the health of the mother and the unborn baby.

An uterine artery doppler scan help the doctor find out if the enough nutrients and oxygen is reaching your placenta.

An Umbilical artery Doppler scan finds out whether your baby is getting enough nutrients and oxygen he needs from your placenta.

If your baby’s growth rate is slow, if you have twins, are affected by rhesus antibodies, if you smoke or have issues with blood pressure, a Doppler during pregnancy can help your doctor give you further instructions, medications and tests.

In short a Doppler test during pregnancy can tell you about the blood circulation in the brain, kidneys, heart, umbilical cord and the placenta of the little one as well as in the uterus. Problems in blood flow can cause abnormalities in growth of the foetus and a timely intervention based on the test results can help you baby and you.

Types of doppler scans during pregnancy phase:

There are 3 types of doppler scans. They are  as follows.

  • Continuous Wave Doppler
  • Duplex Doppler
  • Colour Doppler

#1. Continuous Wave Doppler

Here the change in the pitch of the echoes is monitored to find out about blood flow.

The change can then be used to figure out if there are any blocks or any areas where blood is not flowing. This is also called Bedside Doppler.

Well, no points for guessing why it is called so. It can be done at the bedside at the hospital. It can be used to give fast results.

#2. Duplex Doppler

This method gives you an image of the blood vessel and organs around it. It doesn’t stop there, it also helps convert the sounds into a graph. This graph will tell the doctor about the speed of the blood flow. It will also show the direction of the flow.

#3. Color Doppler

This is similar to the Duplex Doppler as here too an image of the blood vessel is produced. Then the sounds are converted into colours that are superimposed on the image of the blood vessel. This scan shows the speed and direction of blood flow too, like the Duplex Doppler.

There is a type of Colour Doppler called Power Doppler. This comes to play when it is difficult for the normal Colour Doppler to get the job done. It helps to find out blood flow in solid organs.

How does doppler test work?

As you now know, the Doppler test during pregnancy is just like your normal scan. The sonographer rubs some gel over your tummy and moves the hand held device called transducer probe over your skin.

The ultrasound machine emits high frequency sound waves to the body through this transducer probe. The sound waves travel to varying lengths inside the body and get reflected back. The reflected waves are caught by the probe and it is sent back to the machine.

The machine then computes the data and converts it into a relay of what exactly is happening inside your womb. It can also convert that video into an image.

Yes, the same one that looks more like your baby’s first photo (or the negative of the photo)

Though you can’t figure out much, doctors give you results by analysing the colours seen on the screen.

Most modern sonogram machines have the Doppler function too, so all they have to do is switch to Doppler during your regular scan and they can find out about the baby’s circulatory system. A Doppler scan will take only a few minutes during your normal ultrasound scan.

So how do doctors know about the blood flow looking at a black and white image?

As you know the scan uses high frequency sound waves that go into your body and it echoes back. But in the case of blood it keeps moving. So the echoes are varied as well. Doctors use these variations to find out how fast the blood is flowing.

When does your doctor ask for a doppler test during pregnancy?

 As you reach the last leg of pregnancy, the visits to your doctor also increase.

During these visits, your gynecologist checks your baby’s growth. In case your doctor feels your baby’s growth is not normal, then a Doppler ultrasound test may be suggested by him to rule out/ find the source of the problem.

Apart from this warning signs in your anomaly scan may cause your doctor to prescribe this.

Problems with the placenta is one such reason. As you know, the placenta is very important for your little one. If there is any problem with the position of the placenta, regarding the size or functioning, the doctor might suggest this test to find out more and figure out options and treatment.

Some of the reasons that may warrant this are

  • The mom has high blood pressure or diabetes: 

These conditions can also cause issues in blood flow to the little one.

  • The mom is carrying twins or more: 

If there is more than one baby in the womb, the doctor will need to check if both are thriving well.

  • The mom is a smoker:

 Smoking can cause sluggish blood flow due to the thinning of blood vessels due to Nicotine. Apart from the carbon monoxide present in the cigarette smoke impairs the ability of blood cells to carry oxygen.

  • The mom has suffered a miscarriage before
  • Low or high BMI at the time of conception

This test helps to find out if there is anything that can cause issues at the time of delivery.

 Types of Doppler tests during pregnancy:

You know the different types of Doppler scans. Now we will look at different doppler tests done during pregnancy based on the type of device and the stage of pregnancy you are in.

#1. Doppler scan

It can be done at the same time as your normal ultrasound as uses the same machine. The radiologist will apply a gel over your tummy and pelvic area. Then he will use the ultrasound transducer over the stomach and pelvis, just like in the case of your normal scan.

#2. Transvaginal Doppler

As the name suggest, here the Doppler probe in inserted into the vagina. It helps the doctors check if there is an ectopic pregnancy.

#3. Foetal Doppler

This is a handheld device used to monitor your baby’s heartbeat. This can make the heartbeats of your little one audible to you.

Are doppler test during pregnancy safe?

Ultrasound scans when performed by trained professional are totally safe and can help you wiggle your way out of potential dangers.

Trained sonographers make it a point to avoid Doppler, particularly with a vaginal probe, during early weeks of your pregnancy. Again they will make sure that the probe is not held at a same point for a long time to avoid heating up of the area.

To ensure further safety they will use low levels of ultrasound wherever possible and finish the scan as fast as possible.

So yes a Doppler scan is safe and will not cause any harm if used properly following the guidelines.

Should I buy a hand held Doppler machine to use at home?

There are fetal Doppler heart monitor available in the market, so would be mommies may be tempted to buy one and check their little one’s heartbeat. But this isn’t advised as you may end up with wrong/ misleading results, because, well you aren’t trained. So leave the diagnosis part to the doctor and concentrate on staying healthy.

Mommies, now you know all that you need to know about a doppler test during pregnancy.

Did your doctor recommend a doppler test during pregnancy?

How did you feel when you heard your baby’s heart beats for the first time? Did you go all misty eyed or did you want to jump with glee? Let us know.

Share with us your stories and little moments of happiness during your pregnancy days.

And as for the moms to be, take care and stay safe.


About Author

A stay at home mom for a feisty 19 month old named Ahaana, Chitra Santosh has rekindled her romance with words once again now. Though Arakkonam is her home, she can be seen migrating to Mavelikara, a quaint little town in Alappey during summers. Studies have shown that this has no connection with the migratory patterns of birds.

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