Antepartum obstetric ultrasound examination is very useful to find out any abnormal structure of fetal body, especially main structures of body such as skull, brain, spine, chest, lungs, heart, abdominal wall, and abdominal organs such as stomach, liver, kidneys, and bladder, etc. This includes fetal development in order to confirm or identify fetal age in case that mother if not sure about her exact date of last period in order to estimate due date and prevent post-term birth, check the abnormality of umbilical cord, placenta, and amniotic fluid