The 3D/4D anatomy scan at a special non medical clinic requires your doctor to give you a letter saying they are aware you're doing the scan and you are indeed under prenatal care...just about everyone I know has done the scan to find out the gender early at 16 weeks... I asked my doctor about it and she told me NO she wouldn't send the approval because it isn't medically necessary and I should wait longer anyways. ...I'm quite confused considering at least 20 people I know have done it without problem!??