While playing Sims 3 with the ambitions pack, my family recently had a baby, but the baby doesn't look like any normal Sim baby, it has what looks like robot arms, part of its torso, and robot hand. After a quick google search of any cases like this I'm guessing that it's a simple texture glitch. As a continue playing with the family and the child grows I'll post updates; now onto the pictures.

In this picture it's easy to see the mechanical like hand and robot torso, the Sim holding him is his grandfather in case you wanted to know.

Here is another picture of the babies arm and torso, if you look closely you can see it looks like the entire right arm is mechanical.

In this last picture you can clearly see the all the mechanical like parts, that or a freak texture glitch.