Is having kids essential to marriage?

I worry that somehow by separating the act of love-making from procreation we somehow are feeding the already present gnostic tendencies of our culture. This gnostic tendency is present in the very atmosphere of our culture. It elevates internal, spiritual, self-referential over the external, material, and extrinsic. In this view the truest thing about the world is a first person, self-referential statement.