This page is located on the SimsWiki. To view it in it's original form, click here.
Sims 3 Game Help Categories:

Custom Content  | Installation  | Gameplay Guides  | Technical & Graphics Issues  | Miscellaneous Issues

MTS Help Q&A Forums
A pregnant Sim



Creating offspring is easy - if you know how!

Getting Pregnant

In order to get a sim pregnant, you will need one female sim (young adult or adult) and one male sim (young adult, adult, or elder). Same-sex pregnancy, male pregnancy, and teen pregnancy are not part of the game without hacks. Alien pregnancy is also not part of TS3.

Your sims will need to have a high existing relationship to each other to start with, and you'll need to get your sims in the mood. Unlike in Sims 2, you can't just put two sims with a high relationship on a bed and have them go at it - you've got to get them ready first. Start with lower level romantic interactions - flirts, cuddles, and kisses. You'll know they're ready when the socialization box at the top left of the screen says "(Name) finds (name) extremely irresistible!"

At that point, you can have both sims relax on the same double bed (if they weren't already) and, with one sim selected, click on the other and choose "Try for Baby." Alternately, you can choose it with them both still standing and they'll go and relax on the bed and have at it.

You must choose "Try for Baby" for there to be any chance of getting pregnant in the base game. There is no chance of getting pregnant from woohoo alone without hacks!

Listen carefully as the sims finish up under the covers. If the encounter has resulted in a pregnancy, you will hear a soft tinkling lullaby melody. If you don't hear the melody, you can try again.

Success Chance

The chance to get pregnant is different for each place two Sims can "Try for Baby."

EP Location Success Chance Side Effect
Base Game Bed 75% None
Base Game Rabbithole (City Hall, Science Lab, Military Base, etc.) 50% None
High-End Loft Stuff Heart-Shaped Bed 100% The baby will be born with the Excitable trait.
World Adventures Sarcophagus 75% None
Ambitions Time Machine 55% If Sims tried for baby in the future, the child will be added to the family after two days.
Late Night Elevator 65% None
Late Night Hot Tub 50% - 55% The baby may be born with the Hydrophobic or Party Animal trait.
Generations Shower 50% None
Generations Treehouse 50% Depending on the treehouse Sims tried for baby, the baby will be born with a specific trait.

During Pregnancy

After your sim is pregnant, you'll notice a number of changes...


  • Pregnancy Duration: 3 days (72 hours)
  • Pregnancy needs (quicker bladder decay, fatigue, etc.): 8 hours
  • "Nauseous" moodlet: Starts after 8 hours, but may continue later
  • "Pregnant" moodlet: 24 hours
  • Look fully pregnant (pregnancy bump is gradual - there is no "pop": 36 hours
  • Waddling animation: 40 hours
  • Contractions begin: 70 hours

Days Off

The pregnant mother will get 4 days off from work. Her spouse gets 2 days off after the baby is born.


After 8 hours, all pregnant sims will experience the "Nauseous" moodlet which will say it's from "Unknown Causes." This can cause your sim to vomit and may interrupt other actions so your sim can dash to the toilet to be sick. This can continue throughout the pregnancy but all sims will get it at 8 hours.

After 24 hours, the sim will get a "Pregnant" moodlet with a +20 mood bonus for the duration of the pregnancy.

Pregnant sims can get a "Backache" moodlet which gives -20 mood and lasts for 4 hours, or until the sim gets a massage. You can get a massage at the Day Spa, or have another sim give the massage. The spa gives a long-lasting positive moodlet, so may be a better choice.

When going into labor, your sim will get the "Baby Is Coming! " moodlet. It has no mood effect, but lasts until the sim gives birth.

Social Interactions

Once a sim knows she's pregnant, she has a variety of new social interactions. These include the ability to announce her pregnancy as well as ask other sims feel, listen, or talk to her tummy. Other sims can also do those actions without her asking.

Pregnancy Books

Your sim may get a want to read pregnancy books, or to have the baby's father read pregnancy books. This can boost her mood and improve your chances of getting good traits for the baby (or even getting to choose yourself).

  • For a list of the pregnancy books and more on books in general, see: Game Help:Books


Your sim is in labor - what to do?!

Home Birth & Hospital Birth

After contractions begin, you can choose to send your pregnant sim to give birth at the hospital, or she can stay home. Hospital birth is suggested if your sim's needs are already low, since needs are better regulated in the hospital. You also won't have to worry about the father's needs too, if he goes with her.

Multiple Births

Sims in The Sims 3 can have single births, twins, or triplets.

Buying the fertility treatment lifetime happiness reward goes a long way toward encouraging multiple births (and the chance is greater if both parents have the fertility treatment instead of just one).

You can also influence the chance of twins or triplets by listening to the kids' station on the radio and/or watching the kids' channel on TV. There is no special boost to doing them both at the same time, but if you watch/listen a lot (maximum of 2.5 hours total), then you can increase your chance of twins and triplets up to 50% for twins and up to 10% for triplets (from the default of 5% and 1%).

Baby Gender

Gender of babies is normally 50%/50%, purely random. You cannot outright choose the gender of babies born to your sims. The baby gender is determined by a random number generator which has a predetermined output for a given pregnancy. Think of it like a die that will always roll the same sequence of numbers. That means that loading a savegame from right before birth will always lead to the same gender. Unlike in TS2, you can't reload in TS3 until the baby has the gender you want. However, you can influence it by having your sims eat certain foods.

Eating apples increases the chance of boys. Eating watermelon increases the chance of girls. This works only for pure ingredients but not for items that include apple or watermelon ingredients (such as apple pancakes).

The chance of a particular gender is increased by 10% for each watermelon/apple item eaten, to a maximum of 50%. Thus, the maximum chance of having a particular gender is 100% if your sim eats 5 of a particular item. Until the baby's gender is ultimately determined, the offset to a certain gender can always be changed again by having your sim eat additional watermelons or apples. The chance offset will only be clamped right before the gender is determined, so letting your sim eat e.g. 7 watermelons and 1 apple will lead to an offset of 60% which will be clamped to 50% when the gender is actually determined.

Sims high in the medical profession can predict the gender of a baby. Once the gender has been predicted that way, it is determined and cannot be changed anymore.


Every sim baby is born with two traits. If your sim has had a good mood through the pregnancy, you will get better traits than if she was in a bad mood - and if she was in a great mood, you will get to choose the traits. Reading pregnancy books (or having the father read them) boosts your sim's mood during the pregnancy, and are a good way of ensuring good traits/getting to pick.

Hot Tubs

If your Sim tried for baby in a hot tub, there's a chance the baby will be born with the Hydrophobic or Party Animal trait.

EP Hot Tub Try for Baby Success Chance Hydrophobic Trait Chance Party Animal Trait Chance
Late Night The Maelstrom Hot Tub 50% 25% 50%
Outdoor Living Stuff The Modern Rustic Hot Tub
The Resplendence Hot Tub
Late Night The Serenity Hot Tub 55% 20% 65%
Outdoor Living Stuff The Empress Hot Tub
The Aqueous Garden Hot Tub
The Water Course Hot Tub
Late Night The Majestic Grotto Hot Tub 50% 10% 80%


Sims conceived in a treehouse will have one of the following traits.

EP Treehouse Traits
Generations Kid's Clubhouse Loves The Outdoors, Adventurous
Town Life Stuff Sunny Bungalow Clubhouse
Generations Sci-Fi Hideaway Genius, Eccentric
Generations The Princess and the Pauper Castle Snob


There are other objects that force baby traits, there are these:

EP Object Traits
High-End Loft Stuff The Vibromatic LN3000 Excitable

After Birth Moodlets

Depending on what baby or babies your sim gives birth to, the female sim (and the father) can get one of the following moodlets:

All after-birth moodlets are worth a +80 mood boost and last 24 hours.

Sims 3 Game Help Categories:

Custom Content  | Installation  | Gameplay Guides  | Technical & Graphics Issues  | Miscellaneous Issues

MTS Help Q&A Forums