At the turn of the last century (1900) the birth rate in the Missouri Synod was around 38 per 1000 members, a natural birth rate for an industrialized country with little contraception practiced. All Christian churches and denominations taught that contraception is against God's Word.
In 1930, the Lambeth conference of Anglican bishops became very the first Judeo-Christian authority in ALL of history to deny the biblical prohibition of contraception taught in God's church since He Himself said to Adam and Eve, "Be Fruitful and Multiply," and he killed Onan for practicing it in Genesis 38:10.
From the late 1940s through the late 1950s, the birth rate in the LCMS hovered around 37 per 1000 members, not much different than a half century earlier. At this point, the Missouri Synod still held fast to the biblical teaching, vociferously condemning the acceptance of contraception by the general culture and by the Anglicans.
But in 1959, Concordia Publishing House published a book called "Planned Parenthood" by Professor Alfred Rehwinkel (an otherwise conservative theologian) of Concordia Theological Seminary in St. Louis. This book marked the beginning of the acceptance of contraception within the Missouri Synod. In the book, Rehwinkel praised Margaret Sanger's "brilliance" and "God-given talents." Sanger was the mother of birth control and remains the patron saint of abortionists (as well as eugenics, and euthanasia).
By the late 1960s, the birth rate in the Missouri Synod had dropped by a third to less than 25 per 1000 members.
In 1960, the LCMS baptized 82,000 babies.
In 1981, the LCMS Commission on Theology and Church Relations report on "Human Sexuality" (never adopted in convention) stated: "...in the absence of Scriptural prohibition, there need be no objection to contraception within a marital union which is, as a whole, fruitful." Insert whatever you like into the phrase "as a whole, fruitful" -- whatever that means outside of "childless." This CTCR report did not even attempt to refute the Scriptural prohibition of contraception taught consistently by Christians and OT Jews since the beginning of time.
While total LCMS membership has remained relatively static since 1960, the LCMS baptized only 31,700 children in 2005, a drop of 66% since 1960. We are now, like the rest of the general population, at replacement level fertility levels (about two children per family).
Currently, the casual observer sadly knows the average Lutheran family consists of one or two parents with one to three children (often with various last names). The effect of contraception obviously explains our dwindling Lutheran youth.
I thought you might find these facts illuminating.
P.S. Aaron Wolf has another good article on this in Chronicles Magazine this month (not online). I drew a couple of these figures from that article.