An ultrasonography generation device includes an ultrasonic wave transceiver (1002), a user inputter (1006) which inputs input by an operator, a monitor (1011) capable of displaying an image, an image processor (1005) which generates tomographic image data of a fetus and the placenta based on signals acquired from the ultrasonic wave transceiver and sets a region of interest including a region between the fetus and the placenta according to the input from the inputter when the tomographic image data is displayed on the display, a 3D-ROI corrector (1008) which corrects the region of interest using the region of interest set by the operator and the tomographic image data and determines validity of the corrected region of interest, and a presentation part (1012) which presents the determination result from 3D-ROI corrector. The ultrasonography generation device generates a 3D image of the fetus using the corrected region of interest.