4th house is the period of childhood and the prenatal period. It also covers the old age. Moon is the lord and natural significator of the house. It is a well-known assumption that Moon is strong by night. Similar is the position of planets in this house. They are strong by the night and also when there is some trouble. Jupiter gets exalted here. No planet gives bad effects to the affairs of this house if Moon does not occupy and of the house No. 1, 4, 7 or 10. Even the rank malefics like Rahu and Ketu become benefics for this house is Moon does not occupy any of the quandrangular houses. The bad effects of planets in house No. 4 are transferred to the affairs of the house occupied by Saturn.
For the pre-natal period if any if Jupiter, Sun, Mars or Mercury are in 4th house and child will be safe and healthy in mother's womb before birth and even Rahu or Ketu would not be able to spoil that.