I tell you, there isn't one they gave us 4D one not much different, I just want to know if I'm having a son or a daughter already the wait is killing me. Also to keep it on topic my kid has bigger hands than Alex Smith, suck it KC!We have an appoinment set up for like 3 weeks to go get one done. It is funny the place does 3D and "4D" ultrasounds. I cant wait to find out what the difference is.