OK, so I know how hard it is to have alot of babies and having them be the right gender. 
OK, so first, press [Ctrl] [Shift] [C] all together and that opens up the cheat bar up in 
the top. Type in testingCheatsenabled [true or false]. Type in true. Next, pause the game..
or play it, it does not matter. Then go to the mailbox and press [Shift] and click the mailbox 
at the same time. Press Make Me Know Everyone/Everybody. The go to the people you know tab 
and invite everybody you know. As soon as most of the people show up, pause the game. 
Then [Shift] click somebody. Then press the Change Sim In Create A Sim. When you enter 
Create A Sim change their age to toddler. If you want, you can make them look like how 
you want them to look. You can do this to everybody in the town. Don't forget to buy all 
the items for babies. If you want, you can make new sims in edit town. Even make new homes 
to put extra babies in their, but make sure it doesn't have anydoors so you can enter 
whenever you want! Enjoy!