Some CAD software like the FreeCAD supports import of XML vector graphics (.svg) and can be used to create simple shapes or 3D objects that can be then saved and exported in IGES format. Possibly also can be done in other CAD programs.
Convert XML based scalable vector graphics format to IGES 3D exchange format.
We have found one software suitable in our database for this conversion.
Multiplatform software - convert svg to iges on any platform
An open source multiplatform 3D CAD/MCAD/CAx/CAE/PLM modeler
Convert from svg file format
The table with program actions contains information about what each program is capable of doing with their files. This may be a good pointer for further searches for certain file conversions and help you find the converter you are looking for if our search result is insufficient for you. However, it is far from perfect and may sometimes show results which are not really usable because of the nature of the software handles the files. So a conversion that appears as possible, just because of matched actions, may in fact not be possible.