According to a stunning new report, Chelsea Houska is set to welcome her fourth child into the world next year...

... and she's also set to embark on a brand new world in the very near future.

Why?

Because she is leaving Teen Mom 2.

An original cast member, Houska allegedly told producers weeks ago that she won't return to the franchise next season.

Her final appearance will be on the upcoming reunion special.

This special was filmed on Thursday, The Ashley writes, and it was during this virtual meet-up that Housa's fellow castmates -- Jade Cline, Leah Messer, Kailyn Lowry and Brianna DeJesus -- learned the news.

Explains The Ashley, which broke this story:

“The girls were filming from their homes, along with Dr. Drew and Nessa, and at the end when all of the girls were on-screen together with [the hosts], they let Chelsea make her announcement to them.

"Chelsea told everyone that she has decided that it’s best for her family if they move on from the show, and that it was a really hard decision.

"But that she feels like a weight has been lifted from her shoulders."

Chelsea Houska hails from South Dakota and had her first baby, with ex Adam Lind, as a high school senior.

She met husband Cole DeBoer in 2014 and is now pregnant with this couple's third child, a girl who is due in early 2021.

Over the past month or so, Houska has been on the receiving end of some criticism, mostly due to the way she's featured oldest child Aubree in promotional photos for an eyewear line.

A bunch of trolls out there think this is inappropriate.

Did the backlash play any role in Chelsea deciding to walk away from MTV?

We can't say for certain at the moment.

“The girls were all supportive of her decision, but no one else announced that they were leaving,” The Ashley's source explains, adding:

“It’s obvious Chelsea’s life doesn’t really fit the show anymore, though.”

Indeed, Houska may have earned some ire of late for the reason detailed above -- but she's in a very happy and steady relationship.

There have never been any cheating allegations between her and her husband and the angriest viewers have seemed to get at Cole is when he almost cares too much about his step-daughter.

In other words?

Chelsea is almost too stable of a reality star.

She may very well think she's long moved past the drama of a show such as Teen Mom 2, and producers may very well agree.

Expecting her fourth child, building a new house and launching a lifestyle brand called "Aubree Says," Houska has plenty going on today, tomorrow and down the line.

She'll be busy for awhile, even without cameras following around her every move.

As for Teen Mom 2, however?

Where does this program go now?

It has been picked up for the second half of Season 10, although not yet for Season 11.

With this announcement, Houska becomes the first-ever star to leave on her own accord (Bristol Palin previously quit Teen Mom OG after just one season) and the second to leave overall.

In the spring of 2019, Jenelle Evans was fired as a cast member -- and you know what question he rumor mill will start churning with now, don't you?

Might Evans be brought back in now as a replacement?!?!?!?

View Slideshow: Teen Mom 2 Turns 10: See the Cast Then and Now!