Teen Mom stars Catelynn Lowell and Tyler Baltierra made a big decision in 2009 when they decided to put their daughter Carly up for adoption on MTV's 16 and Pregnant. Now the couple is pregnant, this time on their own terms, and on Saturday they revealed the gender of their second little bundle of joy.

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"Today is the day!" declared Baltierra on Instagram Saturday. "We finally get to find out if we will have a son or a daughter #Anticipation #IsKillingMe".

The father-to-be included park photos of two celebration setups, one with a blue theme and one with a pink one. Later that day Lowell announced that they will in fact be having a girl and the two couldn't be more pleased.

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The MTV star has been posting photos of her baby bump on Instagram for a few weeks now, but even as the couple celebrates their new little one they have not forgotten their first little girl.

"The moment we never wanted to end #ThrowBackThursday #Carly #Adoption #MyGirls," wrote Baltierra on Instagram earlier this month alongside a May 2009 photo of him and Lowell with their newborn baby Carly before giving her up. Carly, now five, continues to live with her adopted family. Over the years, Lowell and Baltierra have remained strong adoption advocates, having desired to give their first child a better life.

Five years later, however, the couple believe they are finally ready to raise a child together and are excited to welcome their second baby girl into the world.

A Teen Mom special featuring Lowell, Mack Bookout, and Amber Portwood will air this fall on MTV. The new season of the series begins in 2015.

Tags: teen mom MTV Reality TV