Fetal Doppler Scan During Pregnancy: In which week should you get it done?

A complete guide on fetal doppler scan for expecting mothers

The term fetal doppler scan is very much relatable when you are pregnant or someone you know is. We all know every pregnancy is different and every woman faces a unique journey. A list of various medical tests and a lot of nutrients and even medicines women need to take to give birth to a healthy baby. During the pregnancy, doctors often seek a doppler scan report to check the growth of the baby. Many of us are still not fully aware of this doppler scan in pregnancy. And when doctors suggest it we find ourselves in a confusion. There are rumors also to make us more puzzled. This article concentrates on everything about doppler scan during pregnancy. So, hold it tight and keep reading!

What is a doppler scan?

A doppler scan is quite similar to an ultrasound scan. It uses high-frequency sound waves (not audible) to rightly determine the speed as well as the direction of the blood flow. Doctors seek doppler test reports to check whether the fetal growth is normal and tissues are carrying enough blood and nutrients or not. The equipment set bounces off bones and tissues and generates the ultrasound and the process records it with a microphone. The procedure is painless. Doctors perform it using a hand-held probe called a transducer.

A gentle gel will be spread all over the belly and the transducer will be pressed softly against the belly skin. It is very much different from the regular ultrasound. The color doppler scan is very much effective in detecting the flow of blood in blood vessels, estimating the speed of the blood flow, determining the direction, detecting blood clots, and so on. Mostly, modern-day ultrasound equipment comes with an inbuilt doppler feature, and both regular ultrasound and doppler scans can be carried out together.

Types of Doppler scan

There are various types of Doppler scans that doctors suggest to their patients based on their physical condition and medical case history. Depending on what needs to be detected, there are 3 types of doppler scan out there, such as-

a. Continuous-wave Doppler scan

This scanning procedure uses a continuous transmission as well as the reception of ultrasound waves in order to accurately measure high velocities of blood flow. But it cannot detect the direction or location of the blood flow. It can only measure speed. It is the most suggested doppler scan type during pregnancy.

b. Duplex doppler

It crafts an image of the blood vessel along with the surrounding organs. At the same time, it can also measure the direction as well as the speed of the blood flow.

c. Color Doppler scan

The color Doppler scan is quite similar to the duplex doppler scan but definitely offers better visualization of the scanned area. In this process, a computer will overlap the color images depicting the blood flow onto the image of the blood vessel along with the surrounding tissue. The different color schemes will show the speed and direction of the blood flow. In order to perform this process, lab doctors use a power doppler to check blood flow in solid organs.

Why do doctors suggest a doppler scan in pregnancy?

In most pregnancy cases, two ultrasound scans are required. One scan should be done during the first trimester to check the number of babies, heartbeat, and growth of the baby, and predict the due date. The next scan is done in the second trimester to detect whether the fetus has any physical abnormalities or not. Doctors conduct it to determine that the baby is growing normally.

If the regular ultrasound result comes with an anomaly in the fetus, it needs to conduct the doppler scan for further and better investigation. This scanning procedure helps in checking the placental blood flow, the fetal umbilical blood flow, and blood flow in the heart and brain. These things ensure that everything in the fetus is normal and growing naturally. If any restriction is there in the path of blood flow, the doctors can determine the reason and do the needful to soothe down everything as soon as possible.

Restricted or reduced blood flow in the fetus can result in reduced birth weight, impaired development, reduced size, and so on. Apart from this, often doctors suggest conducting a special type of Doppler ultrasound called a Transactional Doppler in order to evaluate the risk of strokes in babies. Generally, in-womb babies with sickle cell anemia face such conditions. There are various other scenarios where a doppler scan is important, such as-

• If a woman is carrying twins or more
• If the mother is suffering from high or low BMI
• If the mother has diabetes and high blood sugar
• If the fetus is affected by rhesus antibodies
• The fetus growth rate is low
• If the mother has previous miscarriage history
• If the mother smokes

When may your doctor suggest undergoing a doppler scan during pregnancy?

Doctors suggest doppler tests when various complications or abnormalities are detected in regular ultrasound scans. These complications indicate advanced care for the pregnant woman during the course. Apart from this, doctors can suggest a doppler test for the below reasons-

• Multiple pregnancies

If the mother is carrying more than one baby, it’s important to closely monitor that pregnancy as it turns into a high-risk one. For better monitoring, it’s important to conduct a fetal doppler scan. This type of pregnancy often brings many complications such as TTTS, IUGR, umbilical cord entanglement, and so on. Letting these risks rise may harm both babies and the mother. But a doppler test is really effective in identifying any anomalies or complications with a doppler scan.

• Placental problems

In the womb, there is a placenta that supplies blood, nutrients, and oxygen to the baby from the mother’s baby. Healthy blood flow via the placenta is important to let the baby grow naturally. Many people ask which week fetal doppler scan report is important to detect the anomaly. Generally, during the second trimester, the doctor suggests going for an anomaly detection scan. If the report comes with slower fetal movement, the doctor will be able to identify the cause and do the needful. In the case of placenta previa, the same scan test can be suggested for mothers. Via such scans, it’s easy to detect the placental position.

• Health condition of the mother

The overall health of the mother leaves a great impact on the baby. A doppler test helps in detecting the blood flow rate in the umbilical arteries and the placenta. In some serious health conditions of the mother, blood flow can get interrupted towards arteries and it can result in improper oxygen and nutrient supply to the fetus. If the mother is suffering from high blood pressure and diabetes, it can turn into a complicated pregnancy.

• Health condition of the fetus

If the growth rate of the fetus is not satisfactory in the previous regular ultrasound scan, the doctor can suggest enabling a doppler scan test to analyze things in a deeper way.

For the above conditions, a doctor may suggest a doppler test. The fetal doppler scan cost may seem a bit costly in comparison with regular ultrasound tests. But there are a lot of government facilities that help in conducting such tests at lower costs. Many people have thought that a doppler scan test is suggested only when things are not going well. It creates a sense of tension among them.

Is the doppler scan test safe?

It’s the most common question that many expecting mothers and their families think of if a doctor suggests it. Just like any other ultrasound scan test, it is quite easy and safe. Doppler scan is completely safe when it is done by trained and certified professionals. The sonographer carries out the scan following a set of guidelines to ensure that both the mother and baby are safe during the entire scan procedure. The process can generate a small amount of heat as a consequence. But there will be a thermal index display to check the heat.

Generally, these machines come with a low thermal index and come with various other output settings for different stages of pregnancy. The scan may require 30 minutes and it does not cause any harm to the mother or the baby.

These are all that you should know before undergoing a doppler scan test (obstetric doppler scan or scrotal doppler scan or color doppler scan). But it’s very much important to choose the right diagnostic center to get an accurate scan test report. Before finalizing the diagnostic center, you should do a bit of research on the leading centers available in your locality, check their reviews, procedures, etc, and then decide which one to choose. A diagnostic center with certified and trained professionals, advanced equipment, proper procedure and systems, and full-on security.

A Doppler scan test is quite a regular thing during a pregnancy journey. It’s not that your ultrasound report is containing anomalies and that only for that reason the doctor has suggested this test. For deeper analysis modern-day doctors suggest it. It’s completely safe and easy for expecting mothers and their babies.

This may also be of interest to you: What to expect in a Nuchal Translucency scan during your Pregnancy?

References

1. Alfirevic Z, Stampalija T, Medley N. (2015). Fetal and umbilical Doppler ultrasound in normal pregnancy. NCBI
2. E. Soto-Torres, E. Hernandez-Andrade, E. Huntley, H. Mendez-Figueroa, S. C. Blackwell. (2021). Ultrasound and Doppler findings in pregnant women with SARS-CoV-2 infection. https://obgyn.onlinelibrary.wiley.com

3. Kurt Hecher, Stuart Campbell, Pat Doyle, Kevin Harrington and Kypros Nicolaides. (1995). Assessment of Fetal Compromise by Doppler Ultrasound Investigation of the Fetal Circulation: Arterial, Intracardiac, and Venous Blood Flow Velocity Studies. https://www.ahajournals.org

4. Jostein Grytten, Irene Skau, Anne Eskild, Does the use of Doppler ultrasound reduce fetal mortality? A population study of all deliveries in Norway 1990–2014, International Journal of Epidemiology. academic.oup.com