The fetus depicted in this obstetrical wax model displays a lump on its head known as a caput succedaneum [Latin for "substitute head"]. This is a deformation of the head with a swelling of the occipital region and a distortion of the cranial bones. The anomaly can arise at any stage of delivery. If subjected to moderate pressure, the soft parts of the head form a lump mainly affecting the scalp and supra-osseous connective tissue. The fetus of this wax model is detachable and in face presentation. The umbilical cord winds around the neck and the placenta is in fundal position.

The model was commissioned by Felice Fontana, who was working on the installation of the Museo di Fisica e Storia Naturale of Florence, from the sculptor Giuseppe Ferrini and his assistant Clemente Susini.