While it is possible for a male Sim to have a baby by way of alien abduction, it is much simpler and easier to go the traditional route of having a female Sim get pregnant. As in real life, babies cost money, so your Sims should be in a stable financial position when this occurs.
- Get a male and a female Sim together
You need a male and a female Sim that are attracted to each other. Get them together in a bed, hot tub or clothing booth where you may or may not get the Try For Baby option. Odds of success are best in a bed, slightly lower in a clothing booth and very low in a hot tub. If the pregnancy was successful, the female Sim will begin to show signs of it after several days.
- Help the Sim through her pregnancy
Once a female Sim is visibly pregnant, the pregnancy cycle lasts for three days. During this time, she may get sick frequently or be more tired or hungry than usual. This extra stress increases each day of the pregnancy. It is very important to have someone available to cook for her on the third day, or the stress could cause her to die.
- Deliver the baby
At some point on the third day, the Sim delivers her baby automatically. The event cannot be missed. There is a small chance that the Sim could have twins.