1. Get two sims (male and female) who you want to have the baby with. (parents) They must have a high number relationship.2. Have them both stop what they are currently doing (if anything) and they will then have to both "relax" in a double bed.3. Once they are both "relaxing" on the double bed, click on one sims(does not matter) and click "try for baby". NOTE: THIS OPTION WILL NOT APPEAR IF YOUR RELATIONSHIP WITH THE OTHER PERSON IS NOT HIGH ENOUGH, THERE FORE YOU MUST GAIN RELATIONSHIP AND TRY AGAIN.4. Then a video will play of the two "trying for a baby" and finallly at the end If you here a short sound clip you are pregnant! Another way to find out is, after have them both relax again (as you did before) and if "try for baby" is NOT an option, you are pregnant. If it is an option, try it again. There is a 10% chance of having twins. USUALLY when you try more than twice, you have twins. NOT ALWAYS!!!!5. Other signs of pregnancy will be when your female sim throws up and has a baby pacifier sign with question mark in her thought bubble. She will do this a few times. Also different stages appear when the mother (soon to be) gets a bigger stomach. There are three stages of this stomach growth. The father is allowed to rub belly and say "hi" to baby once you start to get big. You also change into maternity everyday clothes and pajamas.TIP: While pregnant let your sim relax often, and try not to do too much work. She gets tired and hungry quick, so let her eat. Also if your mom sim dies from anything, the baby dies to ..... so be careful for both of their sakes. Hope this helped, and have nice baby....... or two! There are also online cheats to having twins automatically. And only adults can or young adults can have kids without cheats. No elders, teens, kids, toddlers, or babies can have babies! DuhOn the sims 2 for the PC you have to have two sims who are in love. have them both relax in a bed and then select "Try for baby" if it workes then there will be a chime and the next day your sim will have a baby bump. her stomach will "pop" twice and on the third day, you have a baby