When two persons ally themselves in the flesh and beget a child, the moment of impregnation is usually–though not invariably–the moment which attaches a soul to the newly conceived body. Hence, much depends upon the influences, astral and magnetic, under which impregnation and conception take place.
The pregnant woman is the centre of a whirl of magnetic forces, and she attracts within her sphere a soul whose previous conduct and odic condition correspond either to her own or to the magnetic influences under which she conceives.
This soul, if the pregnancy continues and progresses, remains attached to her sphere, but does not enter the embryo until the time of quickening, when it usually takes possession of the body, and continues to inhabit it until the time of delivery.
A pregnant woman is swayed not by her own will alone, but as often by the will of the soul newly attached to her sphere; and the opposition and cross-magnetisms of these two wills often occasion many strange and seemingly unaccountable whims, alternations of character, and longings, on the part of the woman.
Sometimes, however, the moment of impregnation or conception passes without attracting any soul, and the woman may even carry a false conception for some time, in which cases abortion occurs. There are innumerable accidents which may happen in this regard. Or, the soul, which has been attracted to her, may, under new influences, be withdrawn from her sphere, and from the embryo which, having quickened, may consume away; or, the soul originally drawn to her orbit may be replaced later by another, and so forth.
Some clairvoyant women have been conscious of the soul attached to them, and have seen it, at times as a beautiful infant, at times in other shapes.
Children begotten by ardent and mutual love are usually the best and healthiest, spiritually and physically, because the radical moment is seized by love, when the astral and magnetic influences are strongest and most ardent, and they attract the strongest and noblest souls.
— from “The Book of the Illuminations” by Anna Bonus Kingsford