Fetal ultrasound is an imaging procedure done during pregnancy that uses reflected sound waves to produce a picture of a fetus, placenta, and amniotic fluid. The image is displayed on a screen.
Fetal ultrasound is used to assess fetal size and position and, because ultrasound images are captured in real-time, they can show the structure and movement of the fetus’ internal organs, as well as blood flowing through blood vessels. Fetal ultrasound does not use x-rays or other types of radiation that may harm the fetus. It can be done as early as the fifth week of pregnancy. Fetal ultrasound can be used to determine the sex of the fetus around the 18th week of pregnancy.