What is a Doppler scan?
A doppler ultrasound is a noninvasive test that is used to measure the blood flow through the umbilical cord and to the different parts of the baby’s body like his brain and heart. The test shows if he is getting all the oxygen and nutrients he needs via the placenta.
Regular ultrasounds uses sound waves to produce images but they can’t show blood flow.
Doppler gives doctors an idea about visual or audible representation of blood movement through veins, arteries and blood vessels with sound waves.
It is conducted through handheld device called transducer.
There are three main types of Doppler Ultrasound: continuous, duplex and color.
- Continuous Doppler Ultrasound
It is also known as Bedside ultrasound. Doctor uses small, portable unit to listen the reflected sounds. The sound waves are audible diagnostic tool as blocked blood vessels make a certain sound as do narrowed and open blood vessels. It is used for a quick diagnosis of potential restrictions in blood flow.
- Duplex Doppler Ultrasound
Along with the sound waves, it produces a visual picture. The dynamism of sound waves make blood vessels to create an image. The sounds are also used to convert the graphs using a computer program to evaluate the direction of blood flow and the speed at which blood is moving.
- Color Doppler Ultrasound
It is similar to duplex doppler ultrasound. Here instead of sound being converted into a graph, a color picture of blood flow speed and movement is created from the sounds.
Power doppler ultrasound : Power doppler comes under color doppler ultrasound. It penetrate organs to look close at what’s going on with blood flow inside the organ. The final image includes a color overlay showing blood speed and direction.
The expecting parents go for scans as they think its their only way to see their little one before the delivery. But for doctors , these scans can determine lot of things regarding health of baby and mother.
- It helps in confirming formal heartbeat.
- It tells about the progress of the pregnancy.
- It checks the status of the umbilical cord.
- It also checks the status of the placenta. As placenta supplies all the nutrients to the baby.
- It tells the position of the baby in the womb. And looking after the position doctor can determine the delivery date.
- It determines the health of the mother.Also any issues or complications like clots or cysts in the mother that can cause problems before or during labour.
- It can tell the general development of the baby in terms of length and weight.
How does doppler test work?
Doppler test during pregnancy is just like normal scan. Sonographer rubs gel over tummy and moves hand held device called transducer probe over the skin.
The ultrasound machine emits high frequency sound waves to the body through this transducer probe. Waves travel to varying lengths inside the body and get reflected back. The reflecting waves are caught by the probe and it is sent back to the machine.
Machine computes data and converts it into a relay of what exactly is happening inside womb. It can also convert that video into an image.
Image looks the same one that more like baby’s first photo.
Why doppler test during pregnancy?
Doctor advice to go for Doppler ultrasound during pregnancy to check foetal umbilical blood flow, placental blood flow and blood flow in the heart and brain. Using the result, doctors determine if restricted blood flow due to sickle cell anaemia, RH sensitisation or restricted blood vessels is to blame for foetal abnormalities.
Restricted blood flow to the foetus could cause:
- Lower birth weight
- Reduced size
- Impaired development
If sickle cell anaemia is diagnosed, child may undergo a special form of Doppler ultrasound known as the transcranial Doppler to evaluate the risk of stroke.
Some more reasons are:
- Mother is suffering from diabetes or high bold pressure. This can cause issues in blood flow to the baby.
- Mother is carrying twins or more.
- Mother is smoker. Smoking causes blood flow slow to the thinning of blood vessels due to Nicotine. Also apart from the carbon monoxide present in the cigarette, smoke impairs the ability of blood cells to carry oxygen.
- Mother has suffered a miscarriage before.
- High or low BMI as the time of conception.
Benefits of Doppler Test in pregnancy
It helps in identifying pregnancy problems non-invasively. It is more reliable than traditional ultrasound procedure. The f an unborn baby can be heard in the early stage around 12 weeks pregnant. Doctors observe and monitor foetal development much earlier than other technologies. This test can also be conducted if pregnant women suspect that their baby’s heart has begun beating earliest by the 5th week of pregnancy.
This scan assures assures healthy pregnancy. Also the high-risk pregnancies due to low amniotic fluid levels, Rh-incompatibility or twins sharing the same placenta.
These scans are extremely necessary to determine that baby is at the best of health and is not having any problems related to blood flow.