Teen Mom stars Catelynn Lowell and Tyler Baltierra welcomed their second child on Jan. 1. Credit: Theo Wargo/Getty Images

New Year's Day baby! Catelynn Lowell and Tyler Baltierra welcomed their second child together on Thursday, Jan. 1. Teen Mom 2 star Kailyn Lowry spilled the beans on Twitter, writing, "Congratulations to my good friends @CatelynnLowell and @TylerBaltierra. cannot wait to meet your new bundle of joy."

Baltierra replied, "Thanks Kail! Can't wait for you to meet her either!"

The couple has not announced an official name, but have been calling their little one "Baby V."

Later that day, proud dad Baltierra tweeted, "OMG guys, my daughter is BEAUTIFUL! Can't wait for you guys to see her! Born on 1/01/15 at 3:15 #StillCantBelieveIt #ShesPerfect."

He later posted a picture of his fiancee holding their baby girl on Instagram, writing, "Momma Bear holding our little angel! Can't tell you the feeling of witnessing this. Look at my beautiful bride to be! That woman is beyond strong, caring, and selfless. Couldn't have asked for a better little family #Blessed #NewYearBAby #MyGirls #AreMyWorld."

On Jan. 1, Baltierra captioned a throwback Instagram photo holding Carly, writing, "IT'S HAPPENING! Here we go, doing this all over again. This is surreal, I'm freakin out a little lol but can't wait to meet my little angel! Thinking a lot about Carly right now. It's bringing me back. Even though I know this time I will actually be taking her home. I love my girls! #CantWait #Nervous #Excited #Scared #Happy." 

Lowell has been ready to meet her baby girl for a while now, tweeting on Sunday, Dec. 28, "38 weeks today now I feel like everyday just drags can't wait to meet our little angel!"

Us broke news back in May that the couple, both 22, were expecting again. Lowell's mom, April Stotts, revealed to Us how the MTV star first found out she was pregnant.

"She called to ask me about a pregnancy test and if I thought she was pregnant. So I made her send me a picture and I told her, 'I believe you are, you should go get a couple more and take a couple more,'" Stotts told Us at the time. "She was crying when she knew for sure and so I was like, 'Are you happy? Are you upset?' And she was like 'I'm happy!'"

Lowell and Baltierra documented the emotional process of placing their first daughter Carly, now 5, for adoption on MTV's 16 and Pregnant in 2009. They called off their wedding in July 2013 after a five-year engagement, but are still together. On Christmas Day, Baltierra presented his longtime love with a new engagement ring.