Color Doppler and three-dimensional ultrasound in the assessment of early human development

Our expanding capability for 3D imaging in normal pregnancies has focused attention on the early weeks of gestation. The embryonic period, extending from conception until 9 weeks gestation, is extremely important. Most major anatomic structures and organ systems are formed and developed during this period. It is during this period that most major developmental anomalies originate. The sequential appearance of embryonic and fetal structures can be visualized by transvaginal ultrasonography as much 3 weeks earlier than with the use of transabdominal ultrasound. On the other hand color Doppler examination enables precise investigation of feto-maternal circulation throughout the pregnancy.