If it were so easy as to use ultrasound, people would do that already. The resolution of ultrasound, even at that little distance, is pretty bad. I doubt if th

If it were so easy as to use ultrasound, people would do that already. The resolution of ultrasound, even at that little distance, is pretty bad. I doubt if the reproductive organs are big enough at that age. If I remember correctly, they don't differ that much at this stage either.