How do you have a baby on sims 3 psp?

If you mean a kitten or a puppy, first you must have two dogs or two cats, one male and one female. They must have a good relationship with each other and be at least friends.

Make sure to have a kennel and get one of the dogs/cats to go into it. You should then click on the animal not in the kennel and direct it to have WooHoo. This should result in a pregnancy.