The ultrasound device transmits sound waves through the body tissue, records echoes when ultrasound finds formations in the body and converts them into the image. The doctor moves the transmitter registrator on the surface of the abdomen. The picture is better if a woman drinks a lot of water and does not urinate before an ultrasound scan.
Ultrasound measures the size and shape of the fetus to determine the stage of pregnancy, possible abnormalities, the presence of twins, the degree of fetus development, is a doctor suspects on fetal growth restriction, position of the fetus in late pregnancy (see abnormal position of the fetus) and position of placenta, and if he suspects you have placenta previa. Ultrasound is a painless procedure and can not harm your child.