The Fourth House relates to those things which are private, such as our home. Planets in this house may affect anything to do with our home life. It is also connected with one's parents and childhood, and hence to the unconscious mind.
A large number of planets in the Fourth House indicates a person whose energies are withdrawn, rather than public. Those planets which are there will indicate energies which are firmly anchored in the past or in a secure sense of belonging. On the other hand, Saturn in the Fourth House would indicate someone whose nurturing energies are held back, possibly causing restrictions in other areas of their life.