To this date, there are no negative side effects, and it is viewed as a safer procedure than X-ray radiation because the ultrasonic waves do not need ionizing radiation. In an examination, the clothing from the abdominal region of the pregnant woman is removed and then the woman lies down upon a table. A water-based gel is rubbed on the skin to aid the transmission of sound waves. Electrical stimulation of the waves comes from the piezoelectric crystal within the transducer. The electric signal goes through signal processing devices, and it is then digitized by scan conversion.
Scan conversion is a tool that changes a processed signal into a representation of lines and curves.
This process is referred to as real-time imaging. Endosonography is a similar technique to ultrasonography. The ovaries, uterus, and fetus are scanned transvaginally as opposed to transabdominally. Ultrasound supplies the doctor with a real-time image of the fetus. Using transvaginal scanning to diagnose malformations has been introduced in the last decade.