4D ultrasound is one of the most accurate prenatal examinations and has the least impact on the fetus. The main purpose of ultrasound is to understand the size and shape of the fetus and the normal development of its organs in three dimensions. During the 4D ultrasound examination, the genitalia of the fetus, such as the male genitalia and female genitalia, can be clearly understood in four dimensions to differentiate between male and female babies. This is one of the most accurate methods of identifying male and female babies.