I refuse to alter the mechanics of Dwarf Fortress in the init.txt file in any way, unless completely necessary. One such example of this is the entry in it for the amount of babies you can have in the fortress. As a consequence, most of my fortresses are bogged down by endless births eventually, leading to much frustration.
... so why don't you mod the init.txt file? It's there for a reason...
I just consider some of the things, like changing the limit to immigration, to just be something like an immigrations and customs official that I just don't have access to inside the game because Toady hasn't gotten around to implimenting whatever feature is going to perform that function in the future.
Likewise, dwarves giving birth every single year from age 12 until they die, potentially as old as 180 or so years of age, for a total of 168 births, not even counting twins, is just plain absurd. Surely, Toady will eventually give us something that will function as "family planning" at some point, but if you just try to find ways to kill the children as soon as they pop out of your girl-dwarf spore-sacs, you might as well enforce "condoms" by changing the init file.