Ultrasound scans internal structures using high-frequency sound waves. The sound waves are generated by a vibrating crystal using a handheld scanner. The sound waves reflected from the scanner are called ‘echoes’. They are then converted into a grainy image that is two-dimensional or sometimes three-dimensional on a monitor.
Ultrasound is used in pregnancy to monitor the baby’s development, and detect any Down syndrome abnormalities. Because the ultrasound scan can’t produce high quality images, any suspicions of abnormalities should be confirmed by other tests. Although the ultrasound scan can’t be 100% accurate, it is non-invasive and painless.
Uses for the ultrasound
Ultrasound can be used at different points in pregnancy.
- First Trimester An ultrasound is performed during the first three months after conception to confirm that the embryo is growing inside the womb. It also determines the due date and the gestational age of the baby.
- The second trimester – an ultrasound is performed between weeks 18-20 to assess the development of fetal structures like the spine, brain, and limbs. Also, the size and position of the placenta can be checked. Parents can also confirm the baby’s sexual history if they wish.
- Third trimester: An ultrasound is performed after 30 weeks to ensure that the baby continues to grow at an appropriate rate. To ensure that the placenta doesn’t block the cervix, it is examined.
Consider Health issues
Ultrasound is non-invasive, painless, and safe. Parents often consider ultrasound a way to see their unborn child, and possibly discover its sex. It is important to remember that ultrasounds are diagnostic procedures and may indicate that there is an abnormality in a fetus. To confirm the diagnosis, additional tests are often required.
This procedure is dependent on the type and use of ultrasound, but could include:
- Transabdominal ultrasound: Sound waves travel very well through water. Your full bladder is used by the sonographer to access your uterus. You will need to drink lots of water prior to the test. The sonographer will place you on a table or a bed. To make the scanner work better, the gel is applied to the abdomen. The sonographer then moves the scanner around in different positions. The images are instantly sent to a nearby monitor. Sometimes, the sonographer will need to push very hard to see deeper structures. It usually takes around 30 minutes to complete the scan.
- Vaginal ultrasound – sometimes a transabdominal ultrasound can’t provide clear images. You may have too much air in your bowel. This is because the air is a poor conductor for sound waves. A slender scanner will be inserted into the vagina. The scan takes approximately 30 minutes.
Right after the ultrasound
After the ultrasound is complete, you will be given tissues to remove the gel and can use the bathroom. You will need to schedule an appointment to receive the report from your doctor.
There are not known side effects, complications or risks for either the mother and her unborn child.
Take care of yourself at your home
An ultrasound scan is non-invasive and painless. You can go about your regular business as usual.
Long term outlook
Your ultrasound results will determine what happens next. A normal result does not mean that your baby will be healthy. Some abnormalities cannot even be detected using this test. You might need to order additional tests if fetal abnormalities are detected. These tests, which include amniocentesis or chorionic villus sampling, can be optional. Before deciding whether to proceed, discuss the risks and benefits of these tests with your doctor.
Other types of pregnancy tests
You may also be offered
- Amniocentesis is a procedure that allows the administration of a small amount amniotic fluid through a thin needle. It involves inserting the needle through the abdomen. An ultrasound guides the needle. The fluid sample is contaminated with cells and then tested in a laboratory to determine if there are any chromosomal abnormalities. One in 250 miscarriages can result from amniocentesis.
- A slender needle is used to sample chorionic villus. It is inserted through the abdomen, cervix or cervix and takes a small amount of placenta. An ultrasound guides the needle. The laboratory then tests the chorionic villi for any chromosomal abnormalities. One in 100 miscarriage is possible after chorionic villus sampling.