If you plan on having only one 4D Ultrasound, we would recommend having the ultrasound performed between the 26th and 32nd week of the pregnancy. The optimal time is generally 28-30 weeks. The farther past 30 weeks you get the more smashed the baby gets in the womb and can make it extremely difficult to capture facial images. If you have an anterior placenta, in the front, we recommend having your ultrasound at 27-28 weeks. If you do not know where your placenta is located your doctor will be able to tell you. Your doctor needs to know this for delivery and checks this at the 18-20 week ultrasound.  Many mothers obtain more than one 4D/HD ultrasound and have images to enjoy from their second and third trimesters.