The Sims 4

The Sims 4 – 14 March Base Game Update – Infants!

Written by deagh

On 14 March 2023, The Sims 4 added a new life stage to the game – infants!  This life stage goes between the “Newborn” (previously called the baby stage) and the “Toddler” stages.  This new stage has brought with it a great deal of additional gameplay as well as many new CAS and Buy/Build items.

Full patch notes can be found here, but this is such a huge update let’s look at what’s included!


First, let’s look at CAS.  Infants are fully creatable and customizable in CAS, so there are many new outfits, hairs, details, and accessories for them!


One of the new details is the “stork bite”, which in real life is a patch of blood vessels near the surface of the skin.  These marks usually fade entirely as a baby gets older, and they will do that for Sims as well.

There are also marks of this type for older sims, as well as stretch marks and C-section scars.


The goal of these details is to really individualize Sims and give players even more storytelling options for their Sims in-game.  I can absolutely see myself giving my legacy Sims some of these marks  I’m actually hoping they can be inherited, but I have not yet had a chance to test this.

There is also now an option on the gender selection screen to choose whether a Sim can produce milk.

So, lots of new ways to customize your Sims in CAS!  Now let’s look at the new build and buy options!


Just as in real life, infants in The Sims 4 need stuff.  A lot of stuff.  So. Much. Stuff.

There are bassinets, cribs, portable cribs, and even baby gate fencing.  A cool new feature of some of the cribs is that they can be converted to toddler beds and back to cribs using the handiness skill.  So the beds can adapt to a changing Sim family.  I usually end up with a selection of bassinets and toddler beds in the household inventory, so having just a few that I can have Sims change to the form they need will be useful.  Some cribs can also be upgraded to have mobiles on them to help soothe baby to sleep.

A new feature that has been added to both the new and existing gates and doors is “Babyproofing”.

You can set gates and doors to be “babyproofed”, which means that infants and toddlers will not be able to go through them.  Previously you had to lock gates and doors for each toddler specifically, so being able to just have one option to keep all the infants and toddlers out of the places you don’t want them to go will be useful.


There is a lot of new gameplay in this update.  There’s a whole new lifestage, of course, but that’s not all, not by a long shot.  This is by no means an exhaustive list, but let’s get into some of the new gameplay that has been added.

Quality of Life Improvements

Skill building now shows the skill being built

Updated Conversation Wheel for Social Interactions

The Social options have been extensively reworked.  The different options such as Friendly, Funny, Romance, etc have subcategories that break the interactions down into types.  This should make it much easier to find that “Get to Know” interaction that you have to have them do for their date!

Science Baby

There’s an entirely new way to have children – the “Science Baby”.  No, it’s not a baby in a lab coat, it’s having a baby through the marvel of modern Sim technology.  A Sim can choose to have a child on their own or with any one of their friends – no romance needed, although you do need to have a certain amount of friendship level for them to accept the request.  Science babies cost §1200.

The parent(s) will go off into a rabbithole and then return with the baby (or babies – it’s possible to have twins and triplets via Science Baby, which I can confirm as I’ve already had it happen).  That’s right – no three days of pregnancy, your Sim gets an insta-baby.

Both science babies and pregnancy babies start out in the “Newborn” stage, which was previously the baby stage.  This is now meant to represent only the time where you first bring a newborn home, so this stage has been shortened.  The other childhood stages are now longer.  Newborns now are supposed to show their genetic skintones and eye colors, although this may not be working correctly at this point, as this family’s newborn  is very different from either of their parents.  This newborn did keep this tone as they aged up, though, so there may be another issue here.

Caring for newborns is now smoother.  Sims will no longer put the baby back in the bassinet between each interaction.  There are also some new options for newborn care, such as choosing feeding preferences.  Once you’ve chosen a feeding preference Sims will automatically use that method when autonomously feeding the newborn, if they’re able to do so.

Infant Traits

When a newborn ages to infant you can assign them one of six traits

These traits determine how your infant reacts to new experiences such as trying new food, bath time, and meeting new Sims.

Infants also have “attachment” to their caregivers.  Infants attach to caregivers based on how quickly a caregiver comes to fill their needs and how much they interact with the infant.  Infants get moodlets based on how quickly (or slowly) their caregivers take care of them, and when they age up they can get one of three traits depending on how well (or not) they were cared for – unhappy infant, happy infant, and top-notch infant.  Which trait they end up with influences them going forward.  It is also possible for them to not get an attachment trait, if their caregiving was neither good nor bad enough to warrant one.

Skill Changes for Children

Previously, children only gained skills in “Child Skills” – Creativity, Mental, Motor, and Social – until they had maxed those skills, and only then would they gain skill in the “Adult” skill related to what they were doing.  So if a child was playing the violin they would gain skill in Creativity until they hit level 10, and only then would they gain skill in Violin.  This meant you could have a teen who had been playing the violin throughout their childhood but was abysmal at it as soon as they aged up.  That has now changed.

Children still build Creativity, Mental, Motor, and Social, but these have been broken out as “Fundamental Skills”.  If a child is using an object that builds adult skill, then they will gain skill in both the fundamental skill and the adult skill, although at a reduced rate for the adult skill.

Cross-pack play

There are also some additions to other packs, according to the SimGurus.  Infants will be able to interact with cats and dogs, the Parenthood pack will have some additional interactions, and Nifty Knitting will have some additional patterns for infants.  If you have Laundry Day Stuff and have laundry items on the lot you will be able to choose between cloth and disposable diapers.


Final Thoughts:

Overall I think this is an amazing addition to the game – the new lifestage gives some good opportunities for family gameplay, plus the addition of the Science Baby option really opens up the possibilities for different combinations of family dynamics.  Even though there is so much that I’ve found so far, I know I still have more to discover!  If you’ve found something new that wasn’t covered here, we’d love to hear from you! @PlatinumSimmers on Twitter and Instagram

The Growing Together pack, which will be out on 16 March, will add yet more family options, which we will discuss in another article.

Happy Simming!

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