Putting together a Teen Mom throwback album feels a bit weird.
So weird, in fact, that featuring their ultrasounds in utero wouldn't be a stretch for the fab four who MTV first introduced us to in 2009.
Since the popular series, which was preceded by 16 & Pregnant, first premiered, a few cast members have had more children.
Maci Bookout and Catelynn Lowell both welcomed new additions in 2015. Jenelle Evans in 2014. Leah Messer has three kids total.
Some have struggled mightily with substance abuse, and at least one infamous "star" enjoys a career in the adult entertainment industry.
Farrah Abraham is in a league of her own, for better or worse.
If you watch Teen Mom online these days, you're watching quasi-celebs in their own right, given the show's surprising staying power.
Yet they were all regular girls at one point, and the authenticity from the olden days still shines through as they progress into adulthood.
With new Teen Mom: OG (original girls, not gangstaz) episodes starting January 4, 2016, let's throw it back to before they were stars ...
Maci Bookout: '16 & Pregnant' Throwback
"Throwback to "16 and Pregnant!" Bentley's mom wrote on Instagram. "I had no idea how much my life would change when I became a parent. I've learned so much about parenthood and teen pregnancy over the years and I encourage you all to do the same."
Caitlynne Lowell and Tyler Baltierra in 2010
"Wow a blast from the past!" Lowell wrote on Instagram. "This is from 5 years ago we are sooo little!"
Leah Messer, Kailyn Lowry, Jenelle Evans, and Chelsea Houska
The cast from 'Teen Mom 2' poses for a photo together in December 2011.
Catelynn Lowell and Tyler Baltierra's Adorable Throwback
The newlyweds in a serious Instagram throwback. "Wow this is from 5 years ago!! I was four months pregnant. Love my babe!" Lowell wrote.
Chelsea Houska: Eyebrow Regrets
"Looking at pictures from high school today just really made me grateful for eyebrow fillers," Teen Mom 2 star Chelsea Houska wrote on Instagram. "No comment on the tongue piercing haa."
Farrah Abraham's Family Flashback
Abraham shared a throwback photo of her mom and daughter, Sofia.
Kailyn Lowry Then and Now
An adorable collage of Teen Mom 2's Kailyn Lowry, from her young and innocent years to the present.
Catelynn Lowell In 7th Grade
"My TBT!" Lowell wrote. "This is in seventh grade when Tyler [Baltierra] and I started dating. Longgg time ago."
Jenelle Evans Then and Now
Yes, that's Jenelle Evans from 16 & Pregnant, before she became one of the Internet's go-to sources for social media selfies.
Maci Bookout at Her Junior Prom
"I went to my junior year prom pregnant," Bookout wrote of a throwback photo. "If you can't imagine doing that, then what are you doing to prevent it?"
Leah Messer and Her Twins
'Teen Mom 2' cast member Leah Messer covered an issue of Us Weekly in 2010.
Catelynn Lowell and Tyler Baltierra's Daughter, Carly, Is Born
"Can you believe that TOMORROW at 10:39am, Carly will be SIX years old?!?! I sure can't! Wish we could celebrate with you kiddo!"
Maci Bookout and Her Son, Bentley in 2009
"Holy throwback! when Bentley and i were both just babies! Cuties #tbt #2009."
Leah Messer Throwbacks
A young Leah Messer of Teen Mom 2, back before her life became unbelievably chaotic and complicated.
Farrah Abraham And Her Parents
"Throwback teenage years," Abraham wrote. "Happy Birthday daddy!"
Catelynn Lowell and Tyler Baltierra: Anniversary Throwback
"Wow today marks 10 YEARS! With my amazing man! Im SO blessed to have you!," Lowell wrote. "Thank you so much for all that you do and for being an amazing daddy! My life would be so dull without you in it...I love you with every ounce of me! Looking forward to the next 10 year and next month you will be my husband!!! xoxo love you to the moon and back!"
Farrah Abraham And Sophia's Dad, Derek
"#HappyDaddysDay to Derek," Abraham posted on her Instagram. "We love and miss you." Derek, Sofia's father, died in a car accident before she was born.
Sophia Abraham As an Infant
"#LateNight #THROWBACK Me and My Booboo :) #SophiaAbraham."
Chelsea Houska Through the Years
Teen Mom 2's Chelsea Houska through five seasons of the hit show. Just as Adam Lind remains as big of a d-bag today as when we first got to know him, Chelsea remains gorgeous with an infectious smile.
Catelynn & Tyler: "Old Throwback"
"This is an old throwback," Lowell wrote. "Me and the babe wayyy back! Love you hun."