A fetal ultrasound, or sonogram, is an imaging technique that uses high-frequency sound waves to produce images of a baby in the uterus.

Fetal ultrasound images can help your health care provider evaluate your baby's growth and development and determine how your pregnancy is progressing. In some cases, fetal ultrasound is used to evaluate possible problems or help confirm a diagnosis.

The first fetal ultrasound is usually done during the first trimester to confirm and date the pregnancy. If your pregnancy remains uncomplicated, the next ultrasound is typically offered during the second trimester, when anatomic details are visible. If your baby's health needs to be monitored more closely, additional ultrasounds might be recommended.

Sept. 19, 2015