Developmental Stages of Human Embryo to Fetus.
The Models can be easily animated to show a progression between the stages, e.g.: using Shapes keys in Blender.
There are four stages shown as their own 3D models, these are as follows:
1. Fetus of 4-5 weeks
2. Fetus of 10 weeks
3. Fetus of 14 weeks
4. Fetus of 20-30 weeks

The models have been published by 3DSurreal Productions, and can be used freely and commercially once paid for in the platforms available.