Ultrasound is an imaging modality that is highly operator dependent. This article reviews the challenges in learning how to perform obstetric sonography, as well as the processes necessary to acquire expert performance skills in sonography. Simulation-based education and learning, and the value of medical simulation are also discussed. Ultrasound simulators are an effective means of teaching obstetric sonography, because it provides training, deliberate practice, and performance evaluation/feedback which allows continuous and critical self-evaluation. We review evidence that simulation can improve performance in obstetric ultrasound examination, review current simulators, and discuss the current problems/gaps in ultrasound simulation. Optical positioning ultrasound simulation is a novel high-fidelity simulation learning system, which addresses many of these problems/gaps and is introduced for the first time here.