Astrology and Karma are co-related just like karma theory, astrology also believes in theory of re-birth, continuity of soul and effects of good or bad karma on individual. The good or bad effects are reflected in the horoscope. The horoscope indicates the past, present and future in respect of the person concerned. The present is the result of past karma and future is also influenced by present and past.
Astrology explains what karmas one has done in his previous birth and what he should experience in this birth and when. These effects are seen in accordance with the major period and sub-period of the planets instrumental in giving effect to the previous birth.
The 5th house in the horoscope shows the link with the past. It is also the house where the balance of karma that we are carrying from the past is indicated. It is the house of Purva janma or previous birth. The ninth house which is the 5th from the 5th house indicates what karma we should be inclined to perform in the present life and also inturns connects us to the future life. 1, 5, 9, are houses of Dharma, 3, 7, and 11 are houses of Karma.
Astrology is telling of events on the basis of horoscope. This is also known as fate. Karma symbolized by planets, rashis and houses in a horoscope. 1, 5 , 9 house are of Dharma principles of righteousness, 2, 6, 10 are of Artha that is materialistic wealth, 3,7,11 are karma that is materialistic desires, and 4,8,12 are Moksha that is salvation or spiritual awakening. The link between astrology and karma is by seeing the majority of planets in houses. Say for example if the planets are in Artha or Karma houses the natives inclination and motivation will be in that direction.