JOEL - This question is about as deep as a bottomless pit :-)
President Harold B. Lee said:

"Let us take a brief glimpse of our premortal life.... You were the sons and daughters of God in the pre-existent world of spirits.... Spirits are organized intelligences that were so prepared before the foundations of the earth were laid, and ... they were organized by our Heavenly Father and dwelt with him while the earth was being formed." (Harold B. Lee, Youth and the Church (Salt Lake City: Deseret Book Co., 1953), pp. 123-125.)

So according to President Lee our spirits were prepared "before" the world was created; so it sounds like He did not have any more after the world was created.

The Prophet Joseph Smith said:
"At the first organization in heaven "we were all present", and saw the Savior chosen and appointed and the plan of salvation made, and we sanctioned it" (Joseph Smith, Teachings of the Prophet Joseph Smith, (Salt Lake City: Deseret Book Co., 1972), p. 181.)

So according to the prophets, in the premortal life all God's spirit children were created before the world was and we were all involved in the great council and war in heaven. We also all had the opportunity to decide which of us would follow God's plan, to "populate worlds without number" and who would follow Satan. With Satan now cast out any subsequent spirit children God might create would not have the opportunity to make that choice. All these points would lead one to believe that God is not creating any more spirit children(at least not at this time and not for this universe). His continued increase will probably come when we are exalted, become god's of our own universes, and create our own spirit children. Perhaps He's really looking forward to being the Grandfather to a lot of grand spirit children :-)