Ultrasound in pregnancy. Pregnant woman receives an ultrasound scan of her abdomen to monitor fetal development. The operator moves a handheld transducer over the woman's lubricated skin, while pointing to a two-dimensional image of the fetus transmitted to the screen. The father is in attendance. Ultrasound scanning is a diagnostic technique which uses high-frequency sound waves to detect body tissues of different density. In pregnancy it is performed to detect gross fetal disorders, and it helps to establish fetal size and healthy development and hence the expected delivery date. The technique is painless and safe.