Get a Teen to Have a Baby in Sims 3 Without Mods

This article will show you how to get a teen to have a baby in The Sims 3 using only cheats.

Steps

Start out with two married Sims, or any other couple who can "Try for a Baby"
Have a baby.
Press the keys Ctrl,Shift, and C at the same time. A blue box will come up and pause your game
Type in testingcheatsenabled true and press enter.
Press the shift key and click on on a Sim while still holding the key down.
Click Edit Sim in Create a Sim
Change their age to teen. You may also change other aspects about your Sim.
Repeat the above two steps on your male Sim.
They will now be married or engaged while they are teens and you won't even need to be pregnant.

Hire a babysitter when they need to go to school or work, it is important to make a schedule on this or the Social worker will not allow you to have a child!
Remember this they can start out as young adults and live as teens just don't turn them into children or they will all be picked up by a social worker and you should be living with a young adult, adult or elder just in case!

When your Sims come back home, make sure you look after the baby as it can be kidnapped.
Your Sims will be a lot more stressed out, be careful.