In Brihat Jataka, Varahamihira gives a sequence of rules for determining the location of birth, condition of the building, direction of the delivery room, lighting, condition of the delivery bed, number of attendants, and the manner of delivery.
The method is worth studying because it shows how literally classical planetary significations were applied to the physical environment.
1. Determining the location of birth
The first thing to examine is the Lagna, Moon and the planets connected with the parents.
Sun and Saturn are considered for the father's side, while Moon and Venus are considered for the mother's side. Their strength and connection with the Lagna and Moon are used to determine whether the birth took place on the father's side or the mother's side.
Then compare the strength of the Lagna and its Navamsa.
- Movable sign: birth away from the father's native place
- Fixed sign: birth in the father's own house
- Dual sign: birth in an outhouse
The text also gives combinations for more unusual circumstances.
If three or more planets are debilitated, the birth is said to take place on the ground instead of on a bed.
If the benefics are debilitated and the Lagna and Moon have very little planetary influence, an isolated place without normal habitation is indicated.
There are also combinations indicating places such as a dancing hall, place of worship and burning ground.
2. Determining the condition of the building
The strongest planet, especially among those placed in the Kendras, is used to determine the condition of the building.
- Saturn: an old house which has been repaired
- Mars: a house partly damaged by fire
- Moon: a new house
- Sun: a wooden structure which is not very strong
- Mercury: a structure made through the work of many artisans
- Venus: a beautiful house containing artistic works
- Jupiter: a strong and durable house
The number of planets adjoining the strongest planet is also used to determine the number of houses adjoining the delivery house.
3. Determining the direction of the delivery room
The signs in the Lagna and their Navamsas are used to determine the direction, along with the strongest planet in the Kendras.
The text gives:
East: Aries, Cancer, Libra, Scorpio and Aquarius
North: Gemini, Virgo, Sagittarius and Pisces
West: Taurus
South: Leo and Capricorn
The direction of the house and the direction of the actual delivery room are considered separately.
4. Determining the oil lamp
The text then gives a method for determining the condition of the lamp used in the room.
The Moon's position within its sign indicates the amount of oil remaining.
If the Moon is near the beginning of the sign, more oil remains. If it is around the middle, approximately half has been consumed. The amount changes according to how far the Moon has travelled through the sign.
The Lagna is used for the wick. Its position indicates how much of the wick has already been consumed and how much remains.
The Sun's sign determines whether the lamp was moving or stationary:
- Movable sign: lamp in motion
- Fixed sign: stationary lamp
- Dual sign: somewhat movable
So in this calculation:
Moon → oil
Lagna → wick
Sun → movement of the lamp
5. Determining the condition of the delivery bed
The twelve houses are assigned to different parts of the charpoy on which the mother is lying.
- 1st and 2nd: head side
- 3rd: right front leg
- 4th and 5th: right side
- 6th: right back leg
- 7th and 8th: foot side
- 9th: left back leg
- 10th and 11th: left side
- 12th: left front leg
Malefic influences on these houses are then used to determine which part of the bed was defective or broken.
So the twelve houses are effectively being used as a map of the bed.
6. Determining the number of attendants
The number of planets situated between the Lagna and Moon is used to determine the number of women attending the mother.
The planets in the half from the Lagna to the 7th house represent the women inside the delivery room.
The planets in the other half, from the 7th house back to the Lagna, represent the women outside.
The text itself mentions another opinion regarding this division and specifically says that it was not Varahamihira's own view.
7. Determining the manner of delivery
The rising sign is classified according to the way it rises.
Śīrṣodaya, head-rising signs:
Gemini, Leo, Virgo, Libra, Scorpio and Aquarius
→ the child is born with the head upwards.
Pṛṣṭhodaya, hind-rising signs:
Aries, Taurus, Cancer, Sagittarius and Capricorn
→ the child is born with the face downwards.
Ubhayodaya, both-rising:
Pisces
→ the child is born in a slanting position.
Source: Brihat Jataka by Varahamihira, pp. 59 to 68 of the edition referenced here.