Ultrasound is a routine test used during pregnancy for monitoring the health, growth and formation of a fetus in the uterus.

Ultrasound (also known as sonography) uses sound waves to produce images on a screen. Ultrasound examinations are non-invasive, and they are safe for the mother and baby.

A small device, known as an ultrasound transducer, is placed on the abdomen along with a water-based gel. Sound waves from the transducer are reflected from the baby and are turned into images on a video screen. Important information about the developing baby and its environment can be obtained.

Your physicians may order several ultrasound exams at various points in your pregnancy. An ultrasound in the first trimester provides information about the number and viability of the fetus or fetuses that you are carrying. It also provides an accurate estimation of your due date.

An ultrasound in the second trimester, usually between 18 and 22 weeks, provides detailed information about the developing organ systems of your baby. Some abnormalities of the fetal head, spine, heart, abdomen, kidneys and extremities can be detected at this time.

An ultrasound exam in the third trimester produces information about the growth and well-being of your baby. Three-dimensional (3D) ultrasound is also available to provide additional information in certain cases.

Different ultrasound techniques exist for different conditions. To learn more, visit Doppler Technology  or Fetal Biophysical Profile.