with the new babies in the patch are they born after a sim gets pregnant?

The baby starts as a newborn (what we already have in game), then transitions to an infant (the new stage they are adding).

Actually, the transition is rather sweet. The Infant floats out of the bassinet (and by the way I love the new design that comes with GT) and softly lands on the floor. Knowing myself I will likely place a mat of some sort in front of the bassinet. I really hate the thought of a baby on the floor or a rug that's been walked on. I'm very excited about Infants, and looking forward to, hopefully, being able to navigate through Growing Together. There appears to be a lot to it. Yikes. Hope my head doesn't explode. LOL

One thing I noticed was anytime the infant is on the floor, a blanket appears on the floor/ground beneath them. I thought that was great.

I really want a chart that shows the age stage durations.
They said they were shortening the newborn stage and extending the others. How short can the newborn stage be? It's already set at 1,2 and 4 days. :o

"JadedJane;c-18239600" wrote:
One thing I noticed was anytime the infant is on the floor, a blanket appears on the floor/ground beneath them. I thought that was great.

I've also noticed that in the livestream. However, I've also noticed that it is only in Growing Together section. That could mean that this is tied to the milestones and once the infant learns to crawl, the floor mat will be gone.

"GalacticGal;c-18239946" wrote:

"Anmirla;c-18239613" wrote:
I really want a chart that shows the age stage durations.
They said they were shortening the newborn stage and extending the others. How short can the newborn stage be? It's already set at 1,2 and 4 days. :o

I think that is determined on which length you play. I play on Long, myself. I think babies take six days to age up to Toddler, currently, but to be honest I never really counted it to know for a certainty. It should be interesting to see if we can still Age Up the baby via the bassinet to hasten things along. Two days from now, all will be revealed, once we get our hands on those wee ones. Can't wait.

According to charts posted, the baby stage right now is 1 day on short, 2 days on normal and 4 days on long. That doesn't leave much wiggle room to shorten the lengths. It definitely should be shorter than infant and infant shorter than toddler which is currently posted as 3, 7 and 28.
I completely get lengthening the later stages, but shortening the newborn when it's already reduced to a minimum seems like it would throw it off a little.
I guess when it comes down to it, it doesn't really matter since so many people complained about the babies and had a tendency to age them up before their time arrived. :D

But I wanna knoooow...

I am not sure, but I think you can either make infants ( not newborns, I don’t think ) in CAS or get the sim pregnant, have them born as newborns and then have them age into infants. And, I also think you can adopt infants. There is also something called science baby that does not show the pregnancy but you can choose parents from close friends or those with enough romance I think. Then, I believe the baby shows up as a newborn.

At The Sims Wiki have a chart
Just still no tested infants at short lifespan (blank entry)

1 | 2 | 4 : Baby
- | 5 | 7 : Infant
3 | 7 | 28 : Toddler
7 | 13 | 52 : Child
7 | 21 | 52 : Teen
11 | 24 | 88 : Young Adult
11 | 33 | 88 : Adult
5 | 14 | 36 : Elder

Total lifespan:

• Short: 45+
  
• Normal: 114+
  
• Long: 348+
  

"leo3487;c-18242010" wrote:
At The Sims Wiki have a chart
Just still no tested infants at short lifespan (blank entry)

1 | 2 | 4 : Baby
- | 5 | 7 : Infant
3 | 7 | 28 : Toddler
7 | 13 | 52 : Child
7 | 21 | 52 : Teen
11 | 24 | 88 : Young Adult
11 | 33 | 88 : Adult
5 | 14 | 36 : Elder

Total lifespan:

• Short: 45+
  
• Normal: 114+
  
• Long: 348+
  

Interesting chart.

A bit off topic but I wonder why there is a difference in length between the child and the teen lifestage in normal lifespan and not in the others. I wish teens wouldn't be dragged out extra long on normal lifespan.

Got the new durations!
https://simscommunity.info/2023/03/15/the-sims-4-life-span-update-sim-age/

Baby Infant Toddler Child Teen Young
Adult Adult Elder

Short 0.5 2.5 3.5 7 10.5 14 21 7
Normal 1 5 7 14 21 28 42 14
Long 4 20 28 56 84 112 168 56

Argh! It didn't copy well. :/

Baby Infant Toddler Child Teen YA Adult Elder
0.5 2.5 3.5 7 10.5 14 21 7
1 5 7 14 21 28 42 14
4 20 28 56 84 112 168 56

Grrr...that still didn't work. Well, the page from the Simscommunity is linked. Sorry I couldn't get the chart more clear.