Does anyone know how to do these mods? Thank you.

[Bluna The Sims]

I would like two mods: A mod that removes the chance of having twins or triplets, which will always only one and a mod that eliminates the chance of having children, which leaves a infertile Sim. I am asking these mods because I have a friend that when you have twin babies, killing one with a mod, and others that the mouse fails and ends up impregnating yes, and they want to abort. Then I wanted the abortion was not necessary, so I ask these mods.
Does anyone know how to do these mods? Thank you.

If English is poor or difficult to understand, forgive me, I'm using a translator. My language is Portuguese.

[Miss Harlequin]

You can use Twallan's StoryProgression mod which allows you to change the pregnancy settings for individual sims, as well as a whole other bunch of things relating to story progression.
http://www.modthesims.info/wiki.php?title=Sims_3:Installing_Package_Files
http://www.the-isz.com/nraas/index.php?topic=77.0

[mangaroo]

Please do not post requests to the Discussion forum. MTS doesn't have a forum for requests.

We do have a forum for people searching for existing mods. In the top menu, you'll find it under Help>Where Can I Find.