The gender of the baby can be determined as early as the first trimester if the ultrasound scan used is 3D or 4D. However because only a few centres have 3D or 4D ultrasound scans the sex is determined usually @ 16-20 weeks in this environment. ( most centres use 2Dachines)It is important to note that the position of the baby and skill of the person doing the scan are also very important

Ultrasounds in the early days of pregnancy may not be the best, most accurate gauge of whether you're expecting a boy or girl. Your baby position is also important. If your little one doesn't cooperate during your ultrasound, you may not get that boy or girl determination until he or she arrives