a good sonographer can most likely determine gender at 12 weeks with reasonable accuracy but at 13 weeks gender determination is close to 99% accurate. waiting until 18-20 weeks offers your ob more information so rather than just do a "wiener" search at 12 weeks it is best to be patient so see if you are having a little boy or girl. just because you are curious or anxious will not medically-justify an earlier sonogram. besides there is nothing that can change gender now!
can you tell gender by 12 weeks? . is the gender of a baby obvious by 12 weeks? i understand we have to be patient and wait 18-20 weeks but i'm just asking out of curiosity. i know at 9 weeks a baby boys and girls genitals look identical but is there a significant change at 12 weeks?