A child is born not just through the genitals but through the heart
The heart is situated within the chest, and although instrumentally the son is born with the aid of the genitals, he is actually born from within the heart. According to the heart’s situation, the semen takes the form of a body. Therefore according to the Vedic system, when one begets a child his heart should be purified through the ritualistic ceremony known as garbhadhana.