Fetal dosimetry studies require the development of accurate 3D models of the fe- tus. This paper proposes a 3D articulated fe- tal growth model including skeleton, body en- velope, brain and lungs based on medical im- ages of 10 dierent fetuses acquired in clinical routine. The structures of interest were semi- manually segmented from the images and sur- face meshes were generated. A generic mesh of each structure has been deformed towards the segmented ones. By interpolating linearly be- tween the subjects of the database, each struc- ture can be estimated at any age and in any position. This process results in an automated model, the operator being only required to specify the age and position of the desired es- timated fetus.