An ultrasound (or sonogram) is a non-surgical method of getting a picture of your baby. Ultrasound involves the use of high-frequency sound waves. The sound waves are directed into your uterus with a small plastic device called a transducer. The sound waved reflect off of bones and tissues and are then converted into black and white images on a screen.
An ultrasound can be done at any time during pregnancy and may be repeated at different stages to monitor your baby’s growth and development if there is cause for concern. An advanced-level (level two) ultrasound is offered only when a problem is suspected. Usually, ultrasounds are offered between the 16th and 20th weeks of pregnancy. By that time, major structural abnormalities can be diagnosed and all four chambers of the heart can be seen (making it possible to detect some congenital heart defects.) A fetal heart can be seen beating as early as 5 or 6 weeks into your pregnancy.
Ultrasound is one of the most valuable methods of evaluating the development of your baby and placenta. Ultrasounds are usually performed: to confirm pregnancy (or detect miscarriage), date the pregnancy (an ultrasound exam is extremely accurate for judging the fetal age before 20 weeks), learn the number of babies, evaluate risks to the pregnancy (such as implantation location of the embryo in an abnormal location), examine the baby for structural malformations, determine the location and development of the placenta, evaluate the growth and development of the baby and asses health of the baby by monitoring movements.
Trans-vaginal ultrasounds are sometimes preferred for investigating pregnancy complications during the first trimester. For this test, a small transducer is inserted in the vagina up to the entrance of the uterus to create images of the baby on the monitor. This can be used in early pregnancy for a better view of the baby and placenta.
—Chorionic Villus Sampling (CVS)
—Contraction Stress test (CST)
—Glucose Tolerance Testing
—Non-Stress (NST) Test
—Triple Screen Test