Have one female and one male Sim who already have an existing relationship (boyfriend/girlfriend or higher) try for a baby. The most common way is in a bed by having them both 'relax' and then clicking the other Sim and the 'try for baby' option. Make sure your sound is up so that you can listen for a jingle. If you hear a jingle, then your Sim is pregnant but she doesn't know it yet. The next day, depending what time you tried for baby, she will know she's pregnant and get the 'Pregnant!' moodlet.
While your Sim is pregnant, do everything you can to improve the pregnancy. Read the two pregnancy books 'Totally Preggers: An expecting mother's tale,' and 'Baby Incoming: Preparing With Vigilance,' and seek medical advice at the hospital. It also helps to find a doctor (In Sunset Valley, go to Jamie Jolina) and ask for advice.The harder you try for a smooth pregnancy, the more likely it will be that you get to choose it's traits. Though it is not a guarantee, have the mother eat 3 watermelons to improve the chances of having a girl, and three apples to improve the chances of having a boy.
Once the baby is born, give it good traits (e.g., Friendly, Good, Excitable, Good sense of humor). It is also beneficial to give it traits like "Workaholic" or specific job traits like "Handy" or "Good Cook" to prepare for future careers. Bring it home and feed it play with it, snuggle it, and interact with it so you and your baby are best/good friends. Make sure the bar is all the way up on their relationship bar. Put him/her in the crib afterwards if he/she is tired. If not, keep interacting with him/her.
Always make sure he/she is in a good mood all the time. If he/she is hungry feed him/her, and if she/he has a dirty diaper change him/her. Never hire a babysitter; they make things worse. For example, they often turn the stereo on while the baby is trying to sleep, or randomly take the baby out of the crib and put them back while ignoring the fact that they are hungry/their nappy is dirty. After all of this, you will have to pay the babysitter money for his/her poor care.
The baby stage does not do much for a child's development, so if you want to, go ahead and buy a birthday cake and make the child age up into a toddler. You do not want to age up any child prematurely unless it is a baby --> toddler transition.
The Sims 3 Guide to Children
Raising Kids: School, Homework, and Skills
Generations Additions: The Sims 3 Generations expansion pack brings many new features to childhood. If you want to read all about the new content for kids in the EP, have a look at Children in Generations. If your child had one as a toddler, they could be developing their Imaginary Friend.
This Sims 3 Guide was originally written for the PC and Mac versions of the game, but also will help owners of the console versions - PS3, Xbox 360 and Wii. Please remember some info or numbers may have changed.
Done a Good Job Raising Them?
If you've followed the parenting guide thus far, and used many of our tips to raising kids, your Sim's child should have been able to choose a trait. In addition, when your child first learns a skill, they will jump up a level immediately if they had training in that skill as a toddler. As such, they can view the skill journal. For example, after playing with the peg toybox for a couple skill levels in the toddler stage, learning the logic skill will immediately start them at level 3 logic once they've grown to a child. This gives your child a head start in school. An odd thing occured the first time my Sim's child slept. She learned the writing skill in her sleep and jumped to level 2.
The Childhood Life Stage
The Sims 3's children are much more like adult Sims than Toddlers. They now have free will, and can learn to cook (but not actually perpare) meals, chat on the computer, learn almost any other skill, go to school, and make friends. You'll also be happy to notice that they can stay home alone. If they spend a bit more time studying, and have a little less fun than other Sim kids, they can shoot straight up any job's career path so long as they maintain this momentum into the teenage years. Here I'll help you with raising a child Sim that tries to excel in life.
Since children cannot cook or fix things, they can play with the little baker oven or genesis building blocks to raise the handiness and cooking skills interactively, while having fun. The skill journal tabs for those skills will appear when they're a teenager. They can learn all other Sims 3 skills the regular ways, aside from Charisma, Guitar, and Gardening. Teens can begin learning those skills. Children can work out with the stereo, television and pool, but an Athletic skill bar will not appear. This may however help them with future development once they age up to teenagers.
Choosing a Child's Lifetime Wish
Watch for lifetime wishes to appear in the wish panel occasionally. They don't pop up often. If you already have a general idea what you want your child's lifetime wish to be, start trying to develop an interest in that trade. For example, if your Sim wants to be a sports star, try to do some athletics (via Pool, Radio, or Television, a hidden skill until Teenager) to increase the odds that the lifetime wish will come up. Likewise for cooking, logic, fishing,and so on.
All children must attend school. Elementary school hours are from 9AM(8 bus) to 3PM. It's just like a career, except the performance meter tops out once your child has an 'A'. There really isn't much to that is different from playing an adult Sim. They will occasionally get school opportunities, such as doing a research project. Their wishes will also sometimes go toward getting on the honor roll for multiple weeks (just have an 'A' grade 3 days in a row).
Children should do their homework daily to boost school performance. If two kids are going to school at the same time, they may want to copy homework off of one another. Drag the homework to a table or other location, and the little cheater can copy the answers straight to their paper. The kid can get detention if caught, however.
Two Children can work together to get the homework done faster, and this doesn't count as cheating. At level 5 in logic, parents can tutor their child to help raise their school performance. Parents can also help kids with homework without fear of detention, as well. It sure beats getting caught cheating! To help, click the child's homework in their inventory. You'll then select which Sim will help them with the homework.
Raising them Well
Keep the kid's mood up, do homework, and have the occasional friend over and your child will do fine in life. I'll add that it's definitely worth it to buy toys like the dollhouse when it comes up, to earn the lifetime happiness points. In fact, childhood is a great time to rack up lifetime happiness and be able to purchase rewards very very early in life.
Give the Kid a Good Birthday!
Make your Child's last birthday as a kid a special one. They're about to grow up into teenagers with more responsibilities and a wide open world.