Ultrasound in Pregnancy

Introduction:

Ultrasound is a diagnostic procedure that uses sound waves to create a picture of a body on a computer screen. This is done to check on the health of the baby and to detect any pregnancy complications. During this test, pictures of a baby (embryo or fetus) within the pregnant mother can also be viewed, along with images of the uterus and ovaries. It does not have any harmful radiation affecting the body and is one of the preferred methods for monitoring the condition of pregnant women and their unborn babies.

What Is an Ultrasound Scan?

Ultrasound scan is a non-invasive imaging technique that helps the physician diagnose multiple medical conditions. Ultrasound imaging is also called sonography. This is a painless procedure that helps in developing images of the inside of the body using sound waves. This test does not use any kind of radiation and does not harm the patient. It emits sound waves that bounce off the tissues, fluids, or bones and create the image.

What Are the Uses of Ultrasound in Pregnancy?

The ultrasound in pregnancy is mainly used for two things which include -

• To evaluate the overall growth and development of the fetus.

• To detect certain complications or medical conditions related to pregnancy.

In the majority of pregnancies, the ultrasound results are normal; however, in some cases, it may also help in finding out some of the following problems which include -

• Confirming the pregnancy.

• Checking pregnancy complications such as early pregnancy, ectopic pregnancy (a fertilized egg grows outside of the uterus), or miscarriage.

• Checking the growth, movement, and heart rate of the baby.

• Evaluating the gestational age and due date of the baby.

• Checking for twins or triplets or more.

• Checking the location of the placenta.

• Checking the baby's position in the uterus.

• Examining the pelvic organs such as the uterus, ovaries, or cervix.

• Identifying any problem with the organs, muscles, or bones.

• To detect any congenital abnormalities.

• Can be done along the biophysical profile (BPP) test to check if the baby is getting enough oxygen.

At What Point During Pregnancy Is an Ultrasound Typically Performed?

The American College of Obstetricians and Gynecologists (ACOG) recommends that pregnant women should get at least one ultrasound in the second trimester, one between 18 and 22 weeks of pregnancy. An additional ultrasound in the first trimester, before the 14th week of pregnancy, may also be needed.

First-Trimester Ultrasound -

An early ultrasound is a routine scan done between six and nine weeks of pregnancy; however, it can be done anytime before week 14. But this scan is not considered a standard scan as it is not possible to see the baby in detail. Therefore, most of the time, the first scan is done after six weeks. Moreover, a fetal heartbeat can be detected at five to six weeks in the scan.

This scan is mostly used for -

• Confirming the due date accurately by measuring the fetus.

• Detecting the heartbeat of the fetus.

• Making sure the location of the pregnancy is in the uterus.

• To check for multiple babies (twin, triplets, or more).

Second-Trimester Ultrasound -

The second scan can be done midway between the pregnancy, during the 18 and 22 weeks, and is also called level 2 ultrasound. This scan provides an overall picture of the health of the baby and pregnancy. The following things can be known from this scan which includes -

• Measuring the size of the baby and checking all major organs.

• Verifying the position of the placenta.

• Checking the amount of amniotic fluid in the uterus.

• Knowing the sex of a baby.

This scan is usually done in two-dimension, but it can also be done in three or four dimensions to examine the fetus more closely and in detail and to detect any anomaly.

Third Trimester Ultrasound -

The third-trimester ultrasound scan or additional scans are mostly not needed in the majority of pregnancies, but if the pregnancy is considered high risk, it may be done which include conditions such as -

• High blood pressure.

• Bleeding.

• Low levels of amniotic fluid.

• Preterm contractions.

• Over age 35.

What Are the Different Kinds of Pregnancy Ultrasounds?

There are different kinds of pregnancy ultrasounds which include -

1. Transabdominal Ultrasound - This is the most common type of ultrasound done during pregnancy. During this test, the pregnant female has to lie down on the exam table. The provider will cover her belly with a thin layer of gel, which helps the sound waves get emitted more easily from the transducer, which is moved all over the belly. Patients have to drink plenty of water before the test to keep the bladder full during the test which helps in the movement of sound waves.

2. Transvaginal Ultrasound - This kind of ultrasound is done through the vagina. The patient has to lie back on the exam table. A thin transducer shaped like a wand is inserted into the vagina. This is done as an additional test to get more information about the baby. The bladder needs to be empty or just partly full during this test.

3. Doppler Ultrasound - This type of ultrasound is used to examine the blood flow in a baby. The transducer is used to listen to the heartbeat of the baby and to measure the blood flow in the umbilical cord and blood vessels. A color Doppler may be used to identify the vessels that will show in red or blue colors, according to the direction of blood flow. This is used in the last trimester but can also be done earlier.

4. 3-D Ultrasound - This scan takes multiple pictures all at once and creates a three-dimensional image as clear as a normal photograph. This is done by some physicians to check the development and growth of the baby's organs, and it can also be done to check for problems in the uterus.

5. 4-D Ultrasound - This scan is the same as a 3-D scan, but it also shows the baby's movements in the womb in a video.

Is Ultrasound Risky?

Ultrasound imaging is a safe and non-invasive procedure that uses low-power sound waves. Till today, there are no known risks of ultrasound. It is a valuable diagnostic tool, but it does have some limitations, such as sound waves do not travel well through bones or air. So body parts that contain gas are hidden by bone, such as the lungs or head.

The body parts that are located deep in the human body may not be visible. Therefore, in that case, the healthcare provider may prescribe other diagnostic tests such as MRI (magnetic resonance imaging) or CT (computed tomography), or X-rays.

Conclusion

Getting an ultrasound during pregnancy can be exciting and terrifying. This test is done for the health and well-being of the fetus as well as the mother. It helps in detecting the growth and development of the child and detecting any complications. Various types of ultrasounds may be prescribed by the health care provider according to the situation. Overall, it is a safe procedure and can be very helpful in pregnancy.