Objective: To demonstrate spatial fetal organ and placental microvasculature using three-dimensional (3D) SlowflowHD. Methods: Seventy normal pregnancies at 11−39 weeks of gestation were studied to demonstrate spatial fetal organ (brain, lung, liver, spleen, adrenal gland, and kidney) and placental microvasculature using 3D SlowflowHD with a new transabdominal mechanical matrix probe. Results: In the first trimester of pregnancy, the whole-body vascularity of the fetus could be clearly depicted. Fetal intracranial vascularity including brain arteries and the venous system could be clearly identified. Characteristic spatial microvasculature of the fetal lung, liver, spleen, adrenal gland, and kidney could be clearly recognized. The microvasculature density of each organ increased with advancing gestation. Spatial relationships among fetal organs were also noted. The increased density of the placental microvasculature with advancing gestation was evident. Conclusion: 3D SlowflowHD can clearly demonstrate spatial fetal organ and placental microvasculature. This modality may provide novel information on normal and abnormal developments of fetal organs and the placenta in clinical practice and future research.