 [ Symptoms ] 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 am 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 [ Disease ] 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