Conception has primary and secondary causes. The primary causes are the father's semen the mother menstrual blood and the consciousness that enters the womb influenced by past life karma delusion, desire and hatred. The semen and menstrual blood should both be healthy; the semen should be white in colour; thick, plenty like honey, and sweet in taste and the menstrual blood should be like red rabbit blood; if it stains it is easily washed. In Tibetan medicine there are nine defects relating to the semen and menstrual blood that may prevent conception. These are here illustrated by the first nine egg like forms.
In addition to the semen menstrual blood and consciousness we need the five elements of earth, water, fire, air and space; these are secondary causes of conception. Earth helps the fetus to be solid; water helps it to cohere; fire to mature; air helps it to grow; and space helps it to move.
The father semen generates bone, the brain and the spinal cord while the mother's menstrual blood generates muscle tissue the five full organs and the six hollow organs. Consciousness develops the five senses.
Earth generates muscle tissue, bone and the nose and its sense of smell. Water generates blood, bodily fluids and the tongue and its sense of taste. Fire generates heat, clarity of complexion and the eyes and their sense of sight. Air generates breath, as well as the skin and its sense of touch. Space generates various orifices, among them the ears and their sense of hearing.
The embryo is thus formed by having healthy semen and menstrual blood, consciousness and the five elements.
The behavior and diet of the mother are very important for healthy development. She should avoid strenuous physical exertion late nights sleeping in the daytime, and eating hot and sharp foods. She should have plenty of fiber; inappropriate diet and behavior may result in miscarriage or stillbirth.
Whatever the mother eats and drinks is digested by her digestive system and its essence is stored in her reproductive organs. They are connected to the two channels of the uterus by the umbilical cord which in turn develops the fetus.
The development of the fetus takes thirty-eight weeks. In the fish stage of development the fetus is fish- shaped with no visible limbs. In the turtle stage the fetus is turtle-shaped; the limbs have appeared, as have the five full organs, the six hollow organs, the sense organs, and the connective nerves and channels. In the pig stage everything is developed and functional; it is called the pig stage because the fetus can now feel the dirtiness of its surroundings.
After thirty- eight weeks the fetus turns upside down and is ready for delivery. Symptoms are heavy feelings in the lower body excruciating back pains, expansion of the vagina and the frequent passing of urine. It is then important to properly care for the mother and child after birth.